2017 |
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| 148. | Dae-Hwan Jung; Seong-Ook Park Ku-band Car-borne FMCW Stripmap Synthetic Aperture Radar Journal Article International Symposium on Antenna and Propagation, 2017. @article{Jung2017, title = {Ku-band Car-borne FMCW Stripmap Synthetic Aperture Radar}, author = {Dae-Hwan Jung and Seong-Ook Park}, year = {2017}, date = {2017-10-31}, journal = {International Symposium on Antenna and Propagation}, keywords = {}, pubstate = {published}, tppubtype = {article} } |
| 147. | Byung-Kwan Kim; Hyunseong Kang; Seong-Ook Park Experimental Analysis of Small Drone Polarimetry Based on Micro-Doppler Signature Journal Article IEEE Geoscience and Remote Sensing Letters, 14 , pp. 1670 - 1674, 2017. @article{Kim2017f, title = {Experimental Analysis of Small Drone Polarimetry Based on Micro-Doppler Signature}, author = {Byung-Kwan Kim and Hyunseong Kang and Seong-Ook Park}, url = {http://143.248.148.42/wordpress/wp-content/uploads/2018/10/08004431.pdf}, doi = {10.1109/LGRS.2017.2727824}, year = {2017}, date = {2017-08-09}, journal = {IEEE Geoscience and Remote Sensing Letters}, volume = {14}, pages = {1670 - 1674}, abstract = {We present a polarimetric analysis of small drones from different aspect angles. Polarimetric analysis can provide more information of a target, since the returned radar signal is affected by different wave polarization. The analysis is performed with micro-Doppler signature (MDS) to investigate micromotions of the drone detected by the radar. We measured operating small drones in an anechoic chamber from two aspect angles, 0° and 90°. An outdoor experiment was carried out with metal clutters for verification in real environment. The indoor analysis result shows that copolarized antenna receives signals better than cross polarized when the aspect angle is 0°, and vice versa. We also verified that cross-polarized antenna receives MDS from the drone better than copolarized antenna, from outdoors when an aspect angle is almost 90°. By utilizing the polarimetric characteristic of the drone at this frequency band, it is preferable to use a polarimetric radar for drone detection.}, keywords = {}, pubstate = {published}, tppubtype = {article} } We present a polarimetric analysis of small drones from different aspect angles. Polarimetric analysis can provide more information of a target, since the returned radar signal is affected by different wave polarization. The analysis is performed with micro-Doppler signature (MDS) to investigate micromotions of the drone detected by the radar. We measured operating small drones in an anechoic chamber from two aspect angles, 0° and 90°. An outdoor experiment was carried out with metal clutters for verification in real environment. The indoor analysis result shows that copolarized antenna receives signals better than cross polarized when the aspect angle is 0°, and vice versa. We also verified that cross-polarized antenna receives MDS from the drone better than copolarized antenna, from outdoors when an aspect angle is almost 90°. By utilizing the polarimetric characteristic of the drone at this frequency band, it is preferable to use a polarimetric radar for drone detection. |
| 146. | Tae-Wan Kim; Rao Shahid Aziz; Seong-Ook Park Design of patch loaded with metallic posts inside dielectric resonator antenna Journal Article IET Microwaves, Antennas & Propagation, 11 , pp. 1483 - 1487, 2017. @article{Kim2017g, title = {Design of patch loaded with metallic posts inside dielectric resonator antenna}, author = {Tae-Wan Kim and Rao Shahid Aziz and Seong-Ook Park}, url = {http://143.248.148.42/wordpress/wp-content/uploads/2018/10/07999329.pdf}, doi = {10.1049/iet-map.2016.1026}, year = {2017}, date = {2017-08-03}, journal = {IET Microwaves, Antennas & Propagation}, volume = {11}, pages = {1483 - 1487}, abstract = {A new hybrid-antenna that is capable of wide-bandwidth operation and is small size is presented. The structure of the proposed antenna consists of a cylindrical dielectric resonator, metallic posts that are embedded in the resonator, and a rectangular patch. The proposed design generates three resonances: the full-cylindrical HE 11δ , half-HE 11δ -like mode, and radiation by the patch antenna. An electromagnetic analysis using a finite integration method (CST microwave studio) was performed to investigate the resonances. Furthermore, a prototype of antenna has fabricated for the experimental verification. The simulation results are in close agreement with the experimental findings. The proposed antenna offers a fractional bandwidth of 16.5% at the centre frequency of 9.27 GHz and a peak gain is >4.56 dBi in the matching band.}, keywords = {}, pubstate = {published}, tppubtype = {article} } A new hybrid-antenna that is capable of wide-bandwidth operation and is small size is presented. The structure of the proposed antenna consists of a cylindrical dielectric resonator, metallic posts that are embedded in the resonator, and a rectangular patch. The proposed design generates three resonances: the full-cylindrical HE 11δ , half-HE 11δ -like mode, and radiation by the patch antenna. An electromagnetic analysis using a finite integration method (CST microwave studio) was performed to investigate the resonances. Furthermore, a prototype of antenna has fabricated for the experimental verification. The simulation results are in close agreement with the experimental findings. The proposed antenna offers a fractional bandwidth of 16.5% at the centre frequency of 9.27 GHz and a peak gain is >4.56 dBi in the matching band. |
| 145. | Seong-Jin Park; Myung-Hun Jeong; Kyung-Bin Bae; Dong-Chan Kim; Laxmikant Minz; Seong-Ook Park IEEE Transactions on Antennas and Propagation, 65 , pp. 6669 - 6678, 2017. @article{Park2018, title = {Performance Comparison of 2×2 MIMO Antenna Arrays With Different Configurations and Polarizations in Reverberation Chamber at Millimeter-Waveband}, author = {Seong-Jin Park and Myung-Hun Jeong and Kyung-Bin Bae and Dong-Chan Kim and Laxmikant Minz and Seong-Ook Park}, url = {http://143.248.148.42/wordpress/wp-content/uploads/2018/10/07997938.pdf}, doi = {10.1109/TAP.2017.2734242}, year = {2017}, date = {2017-07-31}, journal = {IEEE Transactions on Antennas and Propagation}, volume = {65}, pages = {6669 - 6678}, abstract = {A performance comparison of 2 × 2 multiple-input multiple-output (MIMO) antenna arrays with different configurations and polarizations in a reverberation chamber (RC) is presented at the 28-GHz band. Eight types of antenna arrays are proposed according to different configurations and polarizations. The measured results of the antenna arrays show that they have similar antenna performance with respect to the same array size except for those concerning with the polarization. Based on these antenna arrays, we propose twelve cases of 2×2 MIMO antenna arrays with dual-separated polarizations between top and bottom side. A 28-GHz channel sounder and a vector network analyzer were used to measure complex channel transfer functions at the specific position of the rotating mode stirrer in the RC. The proposed MIMO antenna arrays were measured in the RC without and with absorbers. To clarify the channel performance for each case, a wideband channel capacity is calculated from the measured result.}, keywords = {}, pubstate = {published}, tppubtype = {article} } A performance comparison of 2 × 2 multiple-input multiple-output (MIMO) antenna arrays with different configurations and polarizations in a reverberation chamber (RC) is presented at the 28-GHz band. Eight types of antenna arrays are proposed according to different configurations and polarizations. The measured results of the antenna arrays show that they have similar antenna performance with respect to the same array size except for those concerning with the polarization. Based on these antenna arrays, we propose twelve cases of 2×2 MIMO antenna arrays with dual-separated polarizations between top and bottom side. A 28-GHz channel sounder and a vector network analyzer were used to measure complex channel transfer functions at the specific position of the rotating mode stirrer in the RC. The proposed MIMO antenna arrays were measured in the RC without and with absorbers. To clarify the channel performance for each case, a wideband channel capacity is calculated from the measured result. |
| 144. | Jun-Seuk Suh; Laxmikant Minz; Dae-Hwan Jung; Hyunseong Kang; Jong-Wook Ham; Seong-Ook Park Drone-Based External Calibration of a Fully Synchronized Ku-Band Heterodyne FMCW Radar Journal Article IEEE Transactions on Instrumentation and Measurement, 66 , pp. 2189 - 2197, 2017. @article{Suh2017, title = {Drone-Based External Calibration of a Fully Synchronized Ku-Band Heterodyne FMCW Radar}, author = {Jun-Seuk Suh and Laxmikant Minz and Dae-Hwan Jung and Hyunseong Kang and Jong-Wook Ham and Seong-Ook Park}, url = {http://143.248.148.42/wordpress/wp-content/uploads/2018/10/07896553.pdf}, doi = {10.1109/TIM.2017.2687518}, year = {2017}, date = {2017-04-12}, journal = {IEEE Transactions on Instrumentation and Measurement}, volume = {66}, pages = {2189 - 2197}, abstract = {This paper discusses a novel drone-based external radar calibration technique, which utilizes a metal sphere hanging from a drone. The advantages of drone-based calibration are introduced and applied to a dual intermediate-frequency frequency-modulation continuous-wave (FMCW) radar system, which was developed to detect a low radar cross section (RCS) target like a drone with high sensitivity. The developed radar system operates in 150-MHz bandwidth with a frequency sweeping time of 500 μm at Ku-band frequencies. A 75-Ω coaxial cable was utilized in the radar system to physically separate the transmitter (Tx) and receiver (Rx) modules for better isolation. The physical separation with a coaxial cable helps in reducing Tx leakage signal effect, which is a critical concern of typical FMCW radar system, and also it helps the proposed radar system to have higher sensitivity. The designed radar system is a wired system that is fully synchronized with an internal reference clock generator. Offset frequency and other compensation factors were calculated for the calibration of the radar system using a big size metal sphere hanging from a drone. We observed that the theoretical calculations using the standard radar equation and the measurement results on calibration are in good agreement with each other. Furthermore, the RCS value of a small size drone is also investigated using the calibrated radar system. The RCS value estimated for the drone was about -22 dBsm.}, keywords = {}, pubstate = {published}, tppubtype = {article} } This paper discusses a novel drone-based external radar calibration technique, which utilizes a metal sphere hanging from a drone. The advantages of drone-based calibration are introduced and applied to a dual intermediate-frequency frequency-modulation continuous-wave (FMCW) radar system, which was developed to detect a low radar cross section (RCS) target like a drone with high sensitivity. The developed radar system operates in 150-MHz bandwidth with a frequency sweeping time of 500 μm at Ku-band frequencies. A 75-Ω coaxial cable was utilized in the radar system to physically separate the transmitter (Tx) and receiver (Rx) modules for better isolation. The physical separation with a coaxial cable helps in reducing Tx leakage signal effect, which is a critical concern of typical FMCW radar system, and also it helps the proposed radar system to have higher sensitivity. The designed radar system is a wired system that is fully synchronized with an internal reference clock generator. Offset frequency and other compensation factors were calculated for the calibration of the radar system using a big size metal sphere hanging from a drone. We observed that the theoretical calculations using the standard radar equation and the measurement results on calibration are in good agreement with each other. Furthermore, the RCS value of a small size drone is also investigated using the calibrated radar system. The RCS value estimated for the drone was about -22 dBsm. |
| 143. | Woncheol Lee; Yang-Ki Hong; Jihoon Park; Jaejin Lee; In-Seung Baek; Nam-Pal Hur; Won-Mo Seong; Seong-Ook Park A Simple Wireless Power Charging Antenna System: Evaluation of Ferrite Sheet Journal Article IEEE Transactions on Magnetics, 53 , 2017. @article{Lee2017, title = {A Simple Wireless Power Charging Antenna System: Evaluation of Ferrite Sheet}, author = {Woncheol Lee and Yang-Ki Hong and Jihoon Park and Jaejin Lee and In-Seung Baek and Nam-Pal Hur and Won-Mo Seong and Seong-Ook Park}, url = {http://143.248.148.42/wordpress/wp-content/uploads/2018/10/07867861.pdf}, doi = {10.1109/TMAG.2017.2676099}, year = {2017}, date = {2017-03-01}, journal = {IEEE Transactions on Magnetics}, volume = {53}, abstract = {We report a simple wireless power charging (WPC) antenna system (50 mm × 40 mm × 0.1 mm) for use in simulating power transfer efficiency (η) with and without ferrite and a metallic object (battery case), thereby identifying suitable magnetic parameters and ferrite sheet thickness. The simulation results suggest that magnetic loss tangent (tan δ μ ) and permeability (μ') need to be less than 0.05 and higher than 125 at 13.56 MHz, respectively, to achieve at least 75% of the transfer efficiency (η max ) of the WPC antenna without ferrite and the metallic object. Accordingly, we have fabricated Ni x Zn 0.85-x Cu 0.15 Fe 2 O 4 (x = 0.32 - 0.38) spinel ferrites using a one-step sintering process and obtained relatively high μ' of 169 and low tan δ μ of 0.1 with a nickel (Ni) concentration of 0.38. This magnetic loss is still too high to achieve 75% of the η max value. In order to further reduce the magnetic loss, a two-step sintering process was used. The two-step sintered Ni 0.38 Zn 0.47 Cu 0.15 Fe 2 O 4 shows μ' of 132 and a tan δ μ of 0.03 at 13.56 MHz, respectively. Therefore, this ferrite meets criteria identified by the transfer efficiency simulation and is a good candidate for 13.56-MHz wireless power transfer charging antenna system. In addition, our designed WPC system is capable of evaluating other magnetic materials that are suitable for WPC antenna applications.}, keywords = {}, pubstate = {published}, tppubtype = {article} } We report a simple wireless power charging (WPC) antenna system (50 mm × 40 mm × 0.1 mm) for use in simulating power transfer efficiency (η) with and without ferrite and a metallic object (battery case), thereby identifying suitable magnetic parameters and ferrite sheet thickness. The simulation results suggest that magnetic loss tangent (tan δ μ ) and permeability (μ') need to be less than 0.05 and higher than 125 at 13.56 MHz, respectively, to achieve at least 75% of the transfer efficiency (η max ) of the WPC antenna without ferrite and the metallic object. Accordingly, we have fabricated Ni x Zn 0.85-x Cu 0.15 Fe 2 O 4 (x = 0.32 - 0.38) spinel ferrites using a one-step sintering process and obtained relatively high μ' of 169 and low tan δ μ of 0.1 with a nickel (Ni) concentration of 0.38. This magnetic loss is still too high to achieve 75% of the η max value. In order to further reduce the magnetic loss, a two-step sintering process was used. The two-step sintered Ni 0.38 Zn 0.47 Cu 0.15 Fe 2 O 4 shows μ' of 132 and a tan δ μ of 0.03 at 13.56 MHz, respectively. Therefore, this ferrite meets criteria identified by the transfer efficiency simulation and is a good candidate for 13.56-MHz wireless power transfer charging antenna system. In addition, our designed WPC system is capable of evaluating other magnetic materials that are suitable for WPC antenna applications. |
| 142. | Tae-Wan Kim; Byeong-Yong Park; Seong-Ook Park A Theoretical Model for Frequency Response of a Cylindrical Resonator Antenna With the H E-11 delta Mode Splitting Behavior Journal Article IEEE Transactions on Antennas and Propagation, 65 , pp. 1615 - 1623, 2017. @article{Kim2017h, title = {A Theoretical Model for Frequency Response of a Cylindrical Resonator Antenna With the H E-11 delta Mode Splitting Behavior}, author = {Tae-Wan Kim and Byeong-Yong Park and Seong-Ook Park}, url = {http://143.248.148.42/wordpress/wp-content/uploads/2018/10/07856949.pdf}, doi = {10.1109/TAP.2017.2670442}, year = {2017}, date = {2017-02-15}, journal = {IEEE Transactions on Antennas and Propagation}, volume = {65}, pages = {1615 - 1623}, abstract = {This paper presents a theoretical model of a cylindrical hybrid resonator antenna. The hybrid resonator consists of an annular ring ferrite and a cylindrical dielectric with a dc magnetic bias field, applied in direction parallel to the antenna height. The HE 11δ mode splitting behavior caused by tensor nature of the permeability of a biased ferrite is investigated. To validate the proposed approximate analysis, an experimental investigation of an antenna loaded with a biased ferrite is also presented. The presented theory is shown to demonstrate the measured results. The antenna is found to be used as frequency, bandwidth, and polarization tunable antenna. The operating frequency can be chosen in the range from 9.07 to 9.84 GHz. In addition, the bandwidth can be extended from 7.3% to 12.7%. The polarization can be switched from linear to circular. The features mentioned earlier can be achieved by applying the appropriate magnetic field due to the HE 11δ mode splitting behavior. The theoretical model, the design process, and the measured results are presented in detail. The antenna is also found to be capable of tuning the operating frequency as well as the frequency tuning range without changing the overall size of the resonator.}, keywords = {}, pubstate = {published}, tppubtype = {article} } This paper presents a theoretical model of a cylindrical hybrid resonator antenna. The hybrid resonator consists of an annular ring ferrite and a cylindrical dielectric with a dc magnetic bias field, applied in direction parallel to the antenna height. The HE 11δ mode splitting behavior caused by tensor nature of the permeability of a biased ferrite is investigated. To validate the proposed approximate analysis, an experimental investigation of an antenna loaded with a biased ferrite is also presented. The presented theory is shown to demonstrate the measured results. The antenna is found to be used as frequency, bandwidth, and polarization tunable antenna. The operating frequency can be chosen in the range from 9.07 to 9.84 GHz. In addition, the bandwidth can be extended from 7.3% to 12.7%. The polarization can be switched from linear to circular. The features mentioned earlier can be achieved by applying the appropriate magnetic field due to the HE 11δ mode splitting behavior. The theoretical model, the design process, and the measured results are presented in detail. The antenna is also found to be capable of tuning the operating frequency as well as the frequency tuning range without changing the overall size of the resonator. |
2016 |
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| 141. | Dong-Uk Sim; Jong-Hwa Kwon; Seong-Ook Park Design of multiband electromagnetic wave absorber based on a periodic surface for electromagnetic wave measurement facility applications Journal Article Microwave and Optical Technology Letters, 59 , pp. 478 - 481, 2016. @article{Sim2016, title = {Design of multiband electromagnetic wave absorber based on a periodic surface for electromagnetic wave measurement facility applications}, author = {Dong-Uk Sim and Jong-Hwa Kwon and Seong-Ook Park}, url = {http://143.248.148.42/wordpress/wp-content/uploads/2018/10/Sim_et_al-2017-Microwave_and_Optical_Technology_Letters.pdf}, doi = {10.1002/mop.30318}, year = {2016}, date = {2016-12-22}, journal = {Microwave and Optical Technology Letters}, volume = {59}, pages = {478 - 481}, abstract = {In this paper, the periodic structure‐based absorber operating at dual‐band or more for applying to new electromagnetic wave measurement facility that does not contain a conventional pyramidal absorber is presented. To achieve the objective, the absorber structure takes the format of two‐layer periodic surfaces. Based on the logical design principles, the parametric study results to obtain the desired performance and the final experimental result are addressed. The measured result shows a broadband reflectivity characteristic from 0.60 to 3.27 GHz on the basis of below −10 dB. As a result, the absorber shows the performance supporting CDMA, WCDMA, and WLAN bands in the electromagnetic wave measurement facility.}, keywords = {}, pubstate = {published}, tppubtype = {article} } In this paper, the periodic structure‐based absorber operating at dual‐band or more for applying to new electromagnetic wave measurement facility that does not contain a conventional pyramidal absorber is presented. To achieve the objective, the absorber structure takes the format of two‐layer periodic surfaces. Based on the logical design principles, the parametric study results to obtain the desired performance and the final experimental result are addressed. The measured result shows a broadband reflectivity characteristic from 0.60 to 3.27 GHz on the basis of below −10 dB. As a result, the absorber shows the performance supporting CDMA, WCDMA, and WLAN bands in the electromagnetic wave measurement facility. |
| 140. | Myung-Hun Jeong; Tae-Wan Kim; Seong-Ook Park Characteristics Calculation of Ferrite Material Using Frequency Tunable Resonator Journal Article IEEE Transactions on Magnetics, 53 , 2016. @article{Jeong2016, title = {Characteristics Calculation of Ferrite Material Using Frequency Tunable Resonator}, author = {Myung-Hun Jeong and Tae-Wan Kim and Seong-Ook Park}, url = {http://143.248.148.42/wordpress/wp-content/uploads/2018/10/07781609.pdf}, doi = {10.1109/TMAG.2016.2638802}, year = {2016}, date = {2016-12-12}, journal = {IEEE Transactions on Magnetics}, volume = {53}, abstract = {This paper presents an efficient method to measure the permittivity, permeability, and magnetization of ferrite at various resonance frequencies of ferrite resonator. A cylindrical dielectric rod is inserted to annular ring ferrite for tuning the resonance frequency of the ferrite resonator without changing the length of the resonator. The permeability and permittivity of ferrite are calculated using a characteristic equation for resonator in a demagnetized state. The permittivity is compared with the measured results by the cavity perturbation method to verify the calculated results. We analyzed the electromagnetic fields in each region of ferrite, and derived 8 × 8 eigenvalue matrix for the mode-splitting behavior on the HE +111 /HE -111 mode. The induced magnetization of ferrite in the partially magnetized state is calculated by a nonlinear system with the measured resonance frequency. The calculated magnetization of the resonator is a critical parameter to analyze ferrite material, so the calculated results are verified by the magneto-static simulation based on the measured data of B-H curve. Finally, the permeability tensor components at various frequencies are obtained by statistic equations.}, keywords = {}, pubstate = {published}, tppubtype = {article} } This paper presents an efficient method to measure the permittivity, permeability, and magnetization of ferrite at various resonance frequencies of ferrite resonator. A cylindrical dielectric rod is inserted to annular ring ferrite for tuning the resonance frequency of the ferrite resonator without changing the length of the resonator. The permeability and permittivity of ferrite are calculated using a characteristic equation for resonator in a demagnetized state. The permittivity is compared with the measured results by the cavity perturbation method to verify the calculated results. We analyzed the electromagnetic fields in each region of ferrite, and derived 8 × 8 eigenvalue matrix for the mode-splitting behavior on the HE +111 /HE -111 mode. The induced magnetization of ferrite in the partially magnetized state is calculated by a nonlinear system with the measured resonance frequency. The calculated magnetization of the resonator is a critical parameter to analyze ferrite material, so the calculated results are verified by the magneto-static simulation based on the measured data of B-H curve. Finally, the permeability tensor components at various frequencies are obtained by statistic equations. |
| 139. | Dong-Hun Shin; Dae-Hwan Jung; Dong-Chan Kim; Jong-Wook Ham; Seong-Ook Park A Distributed FMCW Radar System Based on Fiber-Optic Links for Small Drone Detection Journal Article IEEE Transactions on Instrumentation and Measurement, 66 , pp. 340 - 347, 2016. @article{Shin2016, title = {A Distributed FMCW Radar System Based on Fiber-Optic Links for Small Drone Detection}, author = {Dong-Hun Shin and Dae-Hwan Jung and Dong-Chan Kim and Jong-Wook Ham and Seong-Ook Park}, url = {http://143.248.148.42/wordpress/wp-content/uploads/2018/10/07762208.pdf}, doi = {10.1109/TIM.2016.2626038}, year = {2016}, date = {2016-11-29}, journal = {IEEE Transactions on Instrumentation and Measurement}, volume = {66}, pages = {340 - 347}, abstract = {This paper discusses a distributed frequency modulation continuous wave radar system. This K-band radar system has high sensitivity, linearity, and flatness to detect low-radar cross section targets and measure their range and velocity. To reduce the leakage between a transmitter and a receiver, the system uses not RF cables but fiber-optic links that have low distortion characteristics and low propagation loss. The transmitter and the receiver are each mounted on a designed fixture to reduce the ground reflections. In addition, they are located on different platforms to reduce the leakage signal flowing directly from the transmitter to the receiver. Measurements in terms of the range and the velocity of a small drone have been carried out to evaluate the proposed distributed radar system. The results show that we can clearly detect the small drone within a 500 m range, which demonstrates the high sensitivity of the system and high isolation between the transmitter and the receiver.}, keywords = {}, pubstate = {published}, tppubtype = {article} } This paper discusses a distributed frequency modulation continuous wave radar system. This K-band radar system has high sensitivity, linearity, and flatness to detect low-radar cross section targets and measure their range and velocity. To reduce the leakage between a transmitter and a receiver, the system uses not RF cables but fiber-optic links that have low distortion characteristics and low propagation loss. The transmitter and the receiver are each mounted on a designed fixture to reduce the ground reflections. In addition, they are located on different platforms to reduce the leakage signal flowing directly from the transmitter to the receiver. Measurements in terms of the range and the velocity of a small drone have been carried out to evaluate the proposed distributed radar system. The results show that we can clearly detect the small drone within a 500 m range, which demonstrates the high sensitivity of the system and high isolation between the transmitter and the receiver. |
| 138. | Hyunseong Kang; Seong-Ook Park Mushroom meta-material based substrate integrated waveguide cavity backed slot antenna with broadband and reduced back radiation Journal Article IET Microwaves, Antennas & Propagation, 10 , pp. 1598 - 1603, 2016. @article{Kang2016, title = {Mushroom meta-material based substrate integrated waveguide cavity backed slot antenna with broadband and reduced back radiation}, author = {Hyunseong Kang and Seong-Ook Park}, url = {http://143.248.148.42/wordpress/wp-content/uploads/2018/10/07755934.pdf}, doi = {10.1049/iet-map.2016.0056}, year = {2016}, date = {2016-11-24}, journal = {IET Microwaves, Antennas & Propagation}, volume = {10}, pages = {1598 - 1603}, abstract = {A novel substrate integrated waveguide (SIW) cavity backed slot antenna with low back radiation is proposed in this study. This newly proposed meta-mushroom antenna uses a SIW cavity to decrease the back radiation. It is fed by the SIW cavity backed slot and radiates by meta-mushroom structure. This antenna exhibits broadband characteristics due to the meta-mushroom structure and a bow-tie slot on the SIW. The back radiation of the proposed antenna is considerably diminished by the SIW cavity located at the back side maintaining high gain performance. After all, its front-to-back ratio is increased and maintained over 19.2 dB in the operating frequency band, 4.5-5.6 GHz. Full-wave simulation and experiments results of the proposed antenna are demonstrated.}, keywords = {}, pubstate = {published}, tppubtype = {article} } A novel substrate integrated waveguide (SIW) cavity backed slot antenna with low back radiation is proposed in this study. This newly proposed meta-mushroom antenna uses a SIW cavity to decrease the back radiation. It is fed by the SIW cavity backed slot and radiates by meta-mushroom structure. This antenna exhibits broadband characteristics due to the meta-mushroom structure and a bow-tie slot on the SIW. The back radiation of the proposed antenna is considerably diminished by the SIW cavity located at the back side maintaining high gain performance. After all, its front-to-back ratio is increased and maintained over 19.2 dB in the operating frequency band, 4.5-5.6 GHz. Full-wave simulation and experiments results of the proposed antenna are demonstrated. |
| 137. | Byung-Kwan Kim; Hyunseong Kang; Seong-Ook Park Drone Classification Using Convolutional Neural Networks With Merged Doppler Images Journal Article IEEE Geoscience and Remote Sensing Letters, 14 , pp. 38 - 42, 2016. @article{Kim2016c, title = {Drone Classification Using Convolutional Neural Networks With Merged Doppler Images}, author = {Byung-Kwan Kim and Hyunseong Kang and Seong-Ook Park}, url = {http://143.248.148.42/wordpress/wp-content/uploads/2018/10/07748505.pdf}, doi = {10.1109/LGRS.2016.2624820}, year = {2016}, date = {2016-11-18}, journal = {IEEE Geoscience and Remote Sensing Letters}, volume = {14}, pages = {38 - 42}, abstract = {We propose a drone classification method based on convolutional neural network (CNN) and micro-Doppler signature (MDS). The MDS only presents Doppler information in time domain. The frequency domain representation of MDS is called as cadence-velocity diagram (CVD). To analyze the Doppler information of drone in time and frequency domain, we propose a new image by merging MDS and CVD, as merged Doppler image. GoogLeNet, a CNN structure, is utilized for the proposed image data set because of its high performance and optimized computing resources. The image data set is generated by the returned Ku-band frequency modulation continuous wave radar signal. Proposed approach is tested and verified in two different environments, anechoic chamber and outdoor. First, we tested our approach with different numbers of operating motor and aspect angle of a drone. The proposed method improved the accuracy from 89.3% to 94.7%. Second, two types of drone at the 50 and 100 m height are classified and showed 100% accuracy due to distinct difference in the result images.}, keywords = {}, pubstate = {published}, tppubtype = {article} } We propose a drone classification method based on convolutional neural network (CNN) and micro-Doppler signature (MDS). The MDS only presents Doppler information in time domain. The frequency domain representation of MDS is called as cadence-velocity diagram (CVD). To analyze the Doppler information of drone in time and frequency domain, we propose a new image by merging MDS and CVD, as merged Doppler image. GoogLeNet, a CNN structure, is utilized for the proposed image data set because of its high performance and optimized computing resources. The image data set is generated by the returned Ku-band frequency modulation continuous wave radar signal. Proposed approach is tested and verified in two different environments, anechoic chamber and outdoor. First, we tested our approach with different numbers of operating motor and aspect angle of a drone. The proposed method improved the accuracy from 89.3% to 94.7%. Second, two types of drone at the 50 and 100 m height are classified and showed 100% accuracy due to distinct difference in the result images. |
| 136. | Byeong-Yong Park; Tae-Wan Kim; AK Ayra; Seung-Young Park; Seong-Ook Park Theory and Design of a Cylindrical Ferrite Resonator Antenna Using HE11 delta Mode Splitting Behavior Journal Article IEEE Transactions on Antennas and Propagation, 64 , pp. 5547 - 5552, 2016. @article{Park2016e, title = {Theory and Design of a Cylindrical Ferrite Resonator Antenna Using HE11 delta Mode Splitting Behavior}, author = {Byeong-Yong Park and Tae-Wan Kim and AK Ayra and Seung-Young Park and Seong-Ook Park}, url = {http://143.248.148.42/wordpress/wp-content/uploads/2018/10/07726002.pdf}, doi = {10.1109/TAP.2016.2623486}, year = {2016}, date = {2016-10-31}, journal = {IEEE Transactions on Antennas and Propagation}, volume = {64}, pages = {5547 - 5552}, abstract = {A theoretical model of a cylindrical ferrite resonator antenna with a dc magnetic bias, applied in the direction parallel to the antenna height, is proposed. HE 11δ mode splitting behavior caused by tensor nature of the permeability of a biased ferrite is investigated. The proposed model is validated through an experimental investigation of the HE 11δ mode antenna. This communication utilizes a Li-ferrite suitable for the antenna applications. The presented theory is shown to correlate well with the measured results. It is also found that HE 11δ mode splitting behavior of the antenna involves frequency and polarization, and bandwidth tuning performances. Therefore, the antenna is a good candidate for a multifunctional antenna.}, keywords = {}, pubstate = {published}, tppubtype = {article} } A theoretical model of a cylindrical ferrite resonator antenna with a dc magnetic bias, applied in the direction parallel to the antenna height, is proposed. HE 11δ mode splitting behavior caused by tensor nature of the permeability of a biased ferrite is investigated. The proposed model is validated through an experimental investigation of the HE 11δ mode antenna. This communication utilizes a Li-ferrite suitable for the antenna applications. The presented theory is shown to correlate well with the measured results. It is also found that HE 11δ mode splitting behavior of the antenna involves frequency and polarization, and bandwidth tuning performances. Therefore, the antenna is a good candidate for a multifunctional antenna. |
| 135. | Jung-Hwan Hwang; Tae-Wook Kang; Jong-Hwa Kwon; Seong-Ook Park Effect of Electromagnetic Interference on Human Body Communication Journal Article IEEE Transactions on Electromagnetic Compatibility, 59 , pp. 48 - 57, 2016. @article{Hwang2016, title = {Effect of Electromagnetic Interference on Human Body Communication}, author = {Jung-Hwan Hwang and Tae-Wook Kang and Jong-Hwa Kwon and Seong-Ook Park}, url = {http://143.248.148.42/wordpress/wp-content/uploads/2018/10/07574274.pdf}, doi = {10.1109/TEMC.2016.2598582}, year = {2016}, date = {2016-09-22}, journal = {IEEE Transactions on Electromagnetic Compatibility}, volume = {59}, pages = {48 - 57}, abstract = {In human body communication (HBC), the human body is used as a medium for transmitting data between devices as a replacement for wired and wireless technologies. The human body functions as an antenna in the low-frequency band used by HBC. Owing to this antenna function, electromagnetic waves radiating from electronic devices or wireless services cause electromagnetic interference (EMI) in HBC devices. This paper addresses such EMI in HBC devices. The interference signal caused by EMI was measured while the human subject, who was using an HBC device, was exposed to a general EMI environment at multiple sites. Using the interference model obtained from the measured interference signals, bit-error-rate degradation caused by the interference signal was simulated. The interference model presented in this paper can be effectively used to achieve reliable data communication in various HBC devices.}, keywords = {}, pubstate = {published}, tppubtype = {article} } In human body communication (HBC), the human body is used as a medium for transmitting data between devices as a replacement for wired and wireless technologies. The human body functions as an antenna in the low-frequency band used by HBC. Owing to this antenna function, electromagnetic waves radiating from electronic devices or wireless services cause electromagnetic interference (EMI) in HBC devices. This paper addresses such EMI in HBC devices. The interference signal caused by EMI was measured while the human subject, who was using an HBC device, was exposed to a general EMI environment at multiple sites. Using the interference model obtained from the measured interference signals, bit-error-rate degradation caused by the interference signal was simulated. The interference model presented in this paper can be effectively used to achieve reliable data communication in various HBC devices. |
| 134. | Seong-Jin Park; Seong-Ook Park LHCP and RHCP Substrate Integrated Waveguide Antenna Arrays for Millimeter-Wave Applications Journal Article IEEE Antennas and Wireless Propagation Letters, 16 , pp. 601 - 604, 2016. @article{Park2016d, title = {LHCP and RHCP Substrate Integrated Waveguide Antenna Arrays for Millimeter-Wave Applications}, author = {Seong-Jin Park and Seong-Ook Park}, url = {http://143.248.148.42/wordpress/wp-content/uploads/2018/10/07523214.pdf}, doi = {10.1109/LAWP.2016.2594081}, year = {2016}, date = {2016-07-27}, journal = {IEEE Antennas and Wireless Propagation Letters}, volume = {16}, pages = {601 - 604}, abstract = {Left-hand and right-hand circularly polarized (LHCP and RHCP) substrate integrated waveguide (SIW) antenna arrays are presented at the 28-GHz band for millimeterwave (mm-wave) applications. Two types of circularly polarized (CP) antenna elements are designed to achieve respective LHCP and RHCP performance. Eight-element LHCP and RHCP antenna arrays have been implemented with feeding networks and measured. Based on the measurement, the LHCP and RHCP antenna arrays have impedance bandwidths of 1.54 and 1.7 GHz within |S 11 | <; -10 dB, whereas 3-dB axial-ratio bandwidths are 1.1 and 1.3 GHz, respectively. Each of the fabricated LHCP and RHCP antenna arrays is accomplished with a gain up to 13.09 and 13.52 dBi. Most of the measured results are validated with the simulated ones. The proposed CP antenna arrays can provide low-cost, broadband characteristics, and high-gain radiation performance with CP properties for mm-wave applications.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Left-hand and right-hand circularly polarized (LHCP and RHCP) substrate integrated waveguide (SIW) antenna arrays are presented at the 28-GHz band for millimeterwave (mm-wave) applications. Two types of circularly polarized (CP) antenna elements are designed to achieve respective LHCP and RHCP performance. Eight-element LHCP and RHCP antenna arrays have been implemented with feeding networks and measured. Based on the measurement, the LHCP and RHCP antenna arrays have impedance bandwidths of 1.54 and 1.7 GHz within |S 11 | <; -10 dB, whereas 3-dB axial-ratio bandwidths are 1.1 and 1.3 GHz, respectively. Each of the fabricated LHCP and RHCP antenna arrays is accomplished with a gain up to 13.09 and 13.52 dBi. Most of the measured results are validated with the simulated ones. The proposed CP antenna arrays can provide low-cost, broadband characteristics, and high-gain radiation performance with CP properties for mm-wave applications. |
| 133. | Jung-Hwan Hwang; Tae-Wook Kang; Chang-Hee Hyoung; Seong-Ook Park Bit error rate degradation model for time-delay parameter of co-channel interference occurring in human body communication Journal Article IET Communications, 10 , pp. 724 - 733, 2016. @article{Hwang2016b, title = {Bit error rate degradation model for time-delay parameter of co-channel interference occurring in human body communication}, author = {Jung-Hwan Hwang and Tae-Wook Kang and Chang-Hee Hyoung and Seong-Ook Park}, url = {http://143.248.148.42/wordpress/wp-content/uploads/2018/10/07452484.pdf}, doi = {10.1049/iet-com.2015.0689}, year = {2016}, date = {2016-04-14}, journal = {IET Communications}, volume = {10}, pages = {724 - 733}, abstract = {Human body communication (HBC) is a new technology for mobile and wearable devices operating over body area networks. In HBC, the body is used as a medium for transmitting data between devices to replace wired and wireless technologies. This study examines the bit error rate (BER) degradation experienced by HBC systems under the presence of co-channel interference. A degradation model is proposed to estimate the change in BER, and a selective simulation method is proposed to obtain the BER performance with a small exceedance probability and a small number of BER samples.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Human body communication (HBC) is a new technology for mobile and wearable devices operating over body area networks. In HBC, the body is used as a medium for transmitting data between devices to replace wired and wireless technologies. This study examines the bit error rate (BER) degradation experienced by HBC systems under the presence of co-channel interference. A degradation model is proposed to estimate the change in BER, and a selective simulation method is proposed to obtain the BER performance with a small exceedance probability and a small number of BER samples. |
| 132. | Rao Shahid Aziz; AK Ayra; Seong-Ook Park Multiband Full-Metal-Rimmed Antenna Design for Smartphones Journal Article IEEE Antennas and Wireless Propagation Letters, 15 , pp. 1987 - 1990, 2016. @article{Aziz2016, title = {Multiband Full-Metal-Rimmed Antenna Design for Smartphones}, author = {Rao Shahid Aziz and AK Ayra and Seong-Ook Park}, url = {http://143.248.148.42/wordpress/wp-content/uploads/2018/10/07442781.pdf}, doi = {10.1109/LAWP.2016.2548018}, year = {2016}, date = {2016-03-29}, journal = {IEEE Antennas and Wireless Propagation Letters}, volume = {15}, pages = {1987 - 1990}, abstract = {In this letter, a multiband full-metal-rimmed antenna covering 10 frequency bands for personal wireless communication terminals is presented. The design antenna is based on simple and effective techniques that are used for metal-rimmed smartphone applications. The proposed antenna with full metal rim is designed on RO4350B substrate within the volume of 130 × 70 × 5 mm 3 . We employed RO4350B substrate with inserted vias as metal rim with height of 5 mm, which surrounds the inner circuit board. The circuit board substrate has a ground plane, which is connected to the metal rim via extended substrate patch. This connection divides the rim into two metal rim strips. The combination of these two strips allows the design to operate on 10 bands. Performing perturbation on the ground plane further adds more operating bands and makes the design an excellent candidate for multiband operation. The designed antenna can be used to serve on GSM850/900, GPS, DCS, PCS, UMTS, WiBro at 2.35 GHz, Bluetooth, ISM, SDM-B at 2.65 GHz, WiMAX at 3.5 GHz, and C-band at 4 GHz wireless communication bands. A prototype antenna was fabricated and tested for input reflection coefficient, radiation performances, antenna gain, and efficiency. The measured and simulated results have been presented and discussed.}, keywords = {}, pubstate = {published}, tppubtype = {article} } In this letter, a multiband full-metal-rimmed antenna covering 10 frequency bands for personal wireless communication terminals is presented. The design antenna is based on simple and effective techniques that are used for metal-rimmed smartphone applications. The proposed antenna with full metal rim is designed on RO4350B substrate within the volume of 130 × 70 × 5 mm 3 . We employed RO4350B substrate with inserted vias as metal rim with height of 5 mm, which surrounds the inner circuit board. The circuit board substrate has a ground plane, which is connected to the metal rim via extended substrate patch. This connection divides the rim into two metal rim strips. The combination of these two strips allows the design to operate on 10 bands. Performing perturbation on the ground plane further adds more operating bands and makes the design an excellent candidate for multiband operation. The designed antenna can be used to serve on GSM850/900, GPS, DCS, PCS, UMTS, WiBro at 2.35 GHz, Bluetooth, ISM, SDM-B at 2.65 GHz, WiMAX at 3.5 GHz, and C-band at 4 GHz wireless communication bands. A prototype antenna was fabricated and tested for input reflection coefficient, radiation performances, antenna gain, and efficiency. The measured and simulated results have been presented and discussed. |
| 131. | Ki-Bok Kong; Woo-Ram Jeong; Seong-Ook Park Design and initial measurements of K-band FMCW rain radar with high resolution Journal Article Microwave and Optical Technology Letters, 58 , pp. 817 - 822, 2016. @article{Kong2016, title = {Design and initial measurements of K-band FMCW rain radar with high resolution}, author = {Ki-Bok Kong and Woo-Ram Jeong and Seong-Ook Park}, url = {http://143.248.148.42/wordpress/wp-content/uploads/2018/10/Kong_et_al-2016-Microwave_and_Optical_Technology_Letters.pdf}, doi = {10.1002/mop.29677}, year = {2016}, date = {2016-02-24}, journal = {Microwave and Optical Technology Letters}, volume = {58}, pages = {817 - 822}, abstract = {This paper presents an FMCW K‐band rain radar with the property of high resolution. The radar system was designed for measurement of localized torrential rain. Using DDS and FPGA control, heterodyne modulation was used to generate the FMCW down‐chirp signal with 50 MHz bandwidth, and emitted a K‐band signal with nominal power of 125 mW in the vertical direction. To obtain high resolution for the Doppler spectrum, the radar system used a coherent signal processing method. Several experiments were conducted and the results were compared with data from the meteorological administration.}, keywords = {}, pubstate = {published}, tppubtype = {article} } This paper presents an FMCW K‐band rain radar with the property of high resolution. The radar system was designed for measurement of localized torrential rain. Using DDS and FPGA control, heterodyne modulation was used to generate the FMCW down‐chirp signal with 50 MHz bandwidth, and emitted a K‐band signal with nominal power of 125 mW in the vertical direction. To obtain high resolution for the Doppler spectrum, the radar system used a coherent signal processing method. Several experiments were conducted and the results were compared with data from the meteorological administration. |
| 130. | Tae-Wan Kim; Byeong-Yong Park; Seung-Young Park; Seong-Ook Park Calculation of Magnetization and Permeability Tensor of a Partially Magnetized Cylindrical Ferrite Resonator Journal Article IEEE Magnetics Letters, 7 , 2016. @article{Kim2016d, title = {Calculation of Magnetization and Permeability Tensor of a Partially Magnetized Cylindrical Ferrite Resonator}, author = {Tae-Wan Kim and Byeong-Yong Park and Seung-Young Park and Seong-Ook Park}, url = {http://143.248.148.42/wordpress/wp-content/uploads/2018/10/07414421.pdf}, doi = {10.1109/LMAG.2016.2532319}, year = {2016}, date = {2016-02-19}, journal = {IEEE Magnetics Letters}, volume = {7}, abstract = {A accurate method of calculating a magnetization and permeability tensor of ferrites is proposed in this paper. We introduce a cylindrical ferrite resonator that is located between parallel metal plates. We theoretically derive exact eigenvalue equations for the mode-splitting phenomenon of the HE111 mode. We also show that the mode-splitting behavior depends on a single magnetization value of the ferrite. The magnetization and permeability tensor components are computed from the measured resonant frequencies of the resonator. We present an analysis of cylindrical ferrite resonator and its experimental results.}, keywords = {}, pubstate = {published}, tppubtype = {article} } A accurate method of calculating a magnetization and permeability tensor of ferrites is proposed in this paper. We introduce a cylindrical ferrite resonator that is located between parallel metal plates. We theoretically derive exact eigenvalue equations for the mode-splitting phenomenon of the HE111 mode. We also show that the mode-splitting behavior depends on a single magnetization value of the ferrite. The magnetization and permeability tensor components are computed from the measured resonant frequencies of the resonator. We present an analysis of cylindrical ferrite resonator and its experimental results. |
| 129. | Dong-Hyuk Choi; Seong-Ook Park Active integrated antenna using T‐shaped microstip‐line‐fed slot antenna Journal Article Microwave and Optical Technology Letters, 48 , 2016. @article{Choi2016, title = {Active integrated antenna using T‐shaped microstip‐line‐fed slot antenna}, author = {Dong-Hyuk Choi and Seong-Ook Park}, url = {http://143.248.148.42/wordpress/wp-content/uploads/2018/10/Choi_et_al-2006-Microwave_and_Optical_Technology_Letters.pdf}, doi = {10.1002/mop.21351}, year = {2016}, date = {2016-02-01}, journal = {Microwave and Optical Technology Letters}, volume = {48}, abstract = {An active integrated antenna (AIA), which consists of a T‐shaped microstrip‐line‐fed slot antenna, is proposed. Since the designed antenna has an electromagnetically coupled feedback loop, it can easily solve the problem of DC isolation between ports of the amplifier. The fabricated parallel feedback antenna oscillator shows stable oscillation at a frequency of 10.05 GHz. The measured EIRP is 37.79 mW, and the cross‐polarization levels are at least −15‐dB lower than those of co‐polarization for all directions.}, keywords = {}, pubstate = {published}, tppubtype = {article} } An active integrated antenna (AIA), which consists of a T‐shaped microstrip‐line‐fed slot antenna, is proposed. Since the designed antenna has an electromagnetically coupled feedback loop, it can easily solve the problem of DC isolation between ports of the amplifier. The fabricated parallel feedback antenna oscillator shows stable oscillation at a frequency of 10.05 GHz. The measured EIRP is 37.79 mW, and the cross‐polarization levels are at least −15‐dB lower than those of co‐polarization for all directions. |
| 128. | Dong-Uk Sim; Jeong-Ho Ju; Jong-Hwa Kwon; Seong-Ook Park An ultracompact CRLH-TL bandpass filter for VHF applications Journal Article Microwave and Optical Technology Letters, 58 , pp. 694 - 697, 2016. @article{Sim2016b, title = {An ultracompact CRLH-TL bandpass filter for VHF applications}, author = {Dong-Uk Sim and Jeong-Ho Ju and Jong-Hwa Kwon and Seong-Ook Park}, url = {http://143.248.148.42/wordpress/wp-content/uploads/2018/10/Sim_et_al-2016-Microwave_and_Optical_Technology_Letters.pdf}, doi = {10.1002/mop.29641}, year = {2016}, date = {2016-01-27}, journal = {Microwave and Optical Technology Letters}, volume = {58}, pages = {694 - 697}, abstract = {This article proposes a new design approach to an ultracompact composite right‐/left‐handed transmission line (CRLH‐TL) bandpass filter with good passband and very broad stopband performances. In order to reduce the size, a series connection of the interdigital capacitor and shorted spiral inductor for realizing CRLH‐TL is adopted and optimized to create the target Terrestrial‐Digital Multimedia Broadcasting (T‐DMB, 174–216 MHz) bandpass filtering. T‐DMB was developed in South Korea. The results of a Bloch impedance analysis suggest that the proposed approach generates good impedance matching. The proposed filter has overall dimensions of λg/19 by λg/34 in terms of a center frequency of 180 MHz, a 3 dB fractional bandwidth of over 28%, an insertion loss of much lower than 2 dB, and a good return loss performance in the predicted and measured results.}, keywords = {}, pubstate = {published}, tppubtype = {article} } This article proposes a new design approach to an ultracompact composite right‐/left‐handed transmission line (CRLH‐TL) bandpass filter with good passband and very broad stopband performances. In order to reduce the size, a series connection of the interdigital capacitor and shorted spiral inductor for realizing CRLH‐TL is adopted and optimized to create the target Terrestrial‐Digital Multimedia Broadcasting (T‐DMB, 174–216 MHz) bandpass filtering. T‐DMB was developed in South Korea. The results of a Bloch impedance analysis suggest that the proposed approach generates good impedance matching. The proposed filter has overall dimensions of λg/19 by λg/34 in terms of a center frequency of 180 MHz, a 3 dB fractional bandwidth of over 28%, an insertion loss of much lower than 2 dB, and a good return loss performance in the predicted and measured results. |
2015 |
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| 127. | Seong-Jin Park; Dong-Hun Shin; Seong-Ook Park Low Side-Lobe Substrate-Integrated-Waveguide Antenna Array Using Broadband Unequal Feeding Network for Millimeter-Wave Handset Device Journal Article IEEE Transactions on Antennas and Propagation, 64 , pp. 923 - 932, 2015. @article{Park2015, title = {Low Side-Lobe Substrate-Integrated-Waveguide Antenna Array Using Broadband Unequal Feeding Network for Millimeter-Wave Handset Device}, author = {Seong-Jin Park and Dong-Hun Shin and Seong-Ook Park }, url = {http://143.248.148.42/wordpress/wp-content/uploads/2018/10/07368120.pdf}, doi = {10.1109/TAP.2015.2513075}, year = {2015}, date = {2015-12-29}, journal = {IEEE Transactions on Antennas and Propagation}, volume = {64}, pages = {923 - 932}, abstract = {A low side-lobe substrate-integrated-waveguide (SIW) antenna array is presented at the 28-GHz band using broadband unequal feeding network for millimeter-wave (mm-wave) handset devices. The ground-plane size of the proposed antenna is fixed to half of the size of the Samsung Galaxy Note 4. The antenna array has been implemented with a multilayer structure created by stacking three substrates and a copper plate. An 8-way SIW feeding network with broadband 4-stage T-junction dividers and a cavity-backed antenna are investigated to obtain broadband performance. The proposed unequal T-junction dividers with phase compensation are introduced and designed for various output ratios. Applying Taylor beam-pattern synthesis in the 8-way SIW feeding network, low side-lobe performance is achieved. The measured result of the fabricated antenna has 2.3 GHz bandwidth within S 11 <; - 10 dB. The fabricated antenna can be performed with a gain up to 13.97 dBi with a low cross-polarization and symmetrical fan beam radiation patterns with low side-lobe levels. Most of the measured results are validated with the simulated results. The proposed antenna array provides low cost, broadband performance, and good radiation performances with low side-lobe levels for mm-wave handset devices.}, keywords = {}, pubstate = {published}, tppubtype = {article} } A low side-lobe substrate-integrated-waveguide (SIW) antenna array is presented at the 28-GHz band using broadband unequal feeding network for millimeter-wave (mm-wave) handset devices. The ground-plane size of the proposed antenna is fixed to half of the size of the Samsung Galaxy Note 4. The antenna array has been implemented with a multilayer structure created by stacking three substrates and a copper plate. An 8-way SIW feeding network with broadband 4-stage T-junction dividers and a cavity-backed antenna are investigated to obtain broadband performance. The proposed unequal T-junction dividers with phase compensation are introduced and designed for various output ratios. Applying Taylor beam-pattern synthesis in the 8-way SIW feeding network, low side-lobe performance is achieved. The measured result of the fabricated antenna has 2.3 GHz bandwidth within S 11 <; - 10 dB. The fabricated antenna can be performed with a gain up to 13.97 dBi with a low cross-polarization and symmetrical fan beam radiation patterns with low side-lobe levels. Most of the measured results are validated with the simulated results. The proposed antenna array provides low cost, broadband performance, and good radiation performances with low side-lobe levels for mm-wave handset devices. |
| 126. | Byeong-Yong Park; Tae-Wan Kim; Seong-Ook Park Metallic post-array loaded cylindrical dielectric resonator antenna Journal Article The Journal of Engineering, pp. 1 - 3, 2015. @article{Park2015b, title = {Metallic post-array loaded cylindrical dielectric resonator antenna}, author = {Byeong-Yong Park and Tae-Wan Kim and Seong-Ook Park}, url = {http://143.248.148.42/wordpress/wp-content/uploads/2018/10/JOE.2015.0182.pdf}, doi = {10.1049/joe.2015.0182}, year = {2015}, date = {2015-11-27}, journal = {The Journal of Engineering}, pages = {1 - 3}, abstract = {An investigation of a novel cylindrical dielectric resonator antenna (DRA) configuration has been carried out. It is shown that two resonances including the full- and half-cylindrical HE 11δ-like modes can coexist simultaneously at different frequencies by placing a metallic post array in the resonator. Moreover, compared with the conventional HE 11δ mode cylindrical DRA having the same size, the proposed antenna operates in lower frequency band and shows improved bandwidth. The experimental results including the return loss and the radiation patterns are demonstrated.}, keywords = {}, pubstate = {published}, tppubtype = {article} } An investigation of a novel cylindrical dielectric resonator antenna (DRA) configuration has been carried out. It is shown that two resonances including the full- and half-cylindrical HE 11δ-like modes can coexist simultaneously at different frequencies by placing a metallic post array in the resonator. Moreover, compared with the conventional HE 11δ mode cylindrical DRA having the same size, the proposed antenna operates in lower frequency band and shows improved bandwidth. The experimental results including the return loss and the radiation patterns are demonstrated. |
| 125. | Dong-Hun Shin; Seong-Jin Park; Jae-We Ahan; Ki-Woong Han; Seong-Ook Park Design of shorted parasitic rhombic array antenna for 24 GHz rear and side detection system Journal Article IET Microwaves Antennas & Propagation, 9 , pp. 1581 - 1586, 2015. @article{Shin2015, title = {Design of shorted parasitic rhombic array antenna for 24 GHz rear and side detection system}, author = {Dong-Hun Shin and Seong-Jin Park and Jae-We Ahan and Ki-Woong Han and Seong-Ook Park}, url = {http://143.248.148.42/wordpress/wp-content/uploads/2018/10/07328558.pdf}, doi = {10.1049/iet-map.2015.0086}, year = {2015}, date = {2015-11-16}, journal = {IET Microwaves Antennas & Propagation}, volume = {9}, pages = {1581 - 1586}, abstract = {A novel microstrip patch antenna is proposed for automotive application. The antenna design has been investigated through both the parametric study and the demonstration of surface currents on the antenna structure. The surface currents related to the co-polarisation increased, and those related to the cross-polarisation is reduced by attaching shorted parasitic element. The four types of single antenna are designed to compare of gain and cross-polarisation level. The cross-polarisation level of proposed antenna has been reduced by 5.9 dB compared with the rhombic antenna. The rhombic array antenna and proposed array antenna were fabricated and tested for input reflection coefficient and radiation performance. The measured and simulated results have been presented and discussed.}, keywords = {}, pubstate = {published}, tppubtype = {article} } A novel microstrip patch antenna is proposed for automotive application. The antenna design has been investigated through both the parametric study and the demonstration of surface currents on the antenna structure. The surface currents related to the co-polarisation increased, and those related to the cross-polarisation is reduced by attaching shorted parasitic element. The four types of single antenna are designed to compare of gain and cross-polarisation level. The cross-polarisation level of proposed antenna has been reduced by 5.9 dB compared with the rhombic antenna. The rhombic array antenna and proposed array antenna were fabricated and tested for input reflection coefficient and radiation performance. The measured and simulated results have been presented and discussed. |
| 124. | Jung-Hwan Hwang; Tae-Wook Kang; Youn-Tae Kim; Seong-Ook Park Measurement of Transmission Properties of HBC Channel and Its Impulse Response Model Journal Article IEEE Transactions on Instrumentation and Measurement, 65 , pp. 177 - 188, 2015. @article{Hwang2015, title = {Measurement of Transmission Properties of HBC Channel and Its Impulse Response Model}, author = {Jung-Hwan Hwang and Tae-Wook Kang and Youn-Tae Kim and Seong-Ook Park}, url = {http://143.248.148.42/wordpress/wp-content/uploads/2018/10/07273899.pdf}, doi = {10.1109/TIM.2015.2476236}, year = {2015}, date = {2015-09-22}, journal = {IEEE Transactions on Instrumentation and Measurement}, volume = {65}, pages = {177 - 188}, abstract = {In human body communication (HBC), the human body is used as a medium for transmitting data between devices in order to replace wired and wireless technologies. This paper presents the measurement results on the transmission properties of an HBC channel and an impulse response model for the HBC channel. The HBC channel was measured with respect to multiple subjects, and the channel parameters were then obtained to analyze the subject dependency of the HBC channel. The HBC channel was modeled using impulse responses that were obtained from the measured channels. The measurement results and the impulse response model can be effectively used to estimate the performance of HBC devices, which is significantly influenced by an HBC channel.}, keywords = {}, pubstate = {published}, tppubtype = {article} } In human body communication (HBC), the human body is used as a medium for transmitting data between devices in order to replace wired and wireless technologies. This paper presents the measurement results on the transmission properties of an HBC channel and an impulse response model for the HBC channel. The HBC channel was measured with respect to multiple subjects, and the channel parameters were then obtained to analyze the subject dependency of the HBC channel. The HBC channel was modeled using impulse responses that were obtained from the measured channels. The measurement results and the impulse response model can be effectively used to estimate the performance of HBC devices, which is significantly influenced by an HBC channel. |
| 123. | AK Ayra; Rao Shahid Aziz; Seong-Ook Park Planar ultra-wideband printed wide-slot antenna using fork-like tuning stub Journal Article Electronics Letters, 51 , pp. 550 - 551, 2015. @article{Ayra2015, title = {Planar ultra-wideband printed wide-slot antenna using fork-like tuning stub}, author = {AK Ayra and Rao Shahid Aziz and Seong-Ook Park}, url = {http://143.248.148.42/wordpress/wp-content/uploads/2018/10/07073714.pdf}, doi = {10.1049/el.2015.0428}, year = {2015}, date = {2015-04-02}, journal = {Electronics Letters}, volume = {51}, pages = {550 - 551}, abstract = {A printed wide-slot antenna with a centred rectangular parasitic patch, fed by a fork-like tuning stub with rectangular parasitic elements adjacent to the main feed line is proposed and discussed. The proposed wide-slot antenna eliminates the need of rotation of the slot and parasitic patches both in the ground plane for the improvement in impedance bandwidth. The experimental results indicate that the presented antenna has a bandwidth (-10 dB) of more than 148% ranging from 2 to 13.5 GHz. The total size of the proposed antenna configuration is 44.3 × 44.3 × 0.508 mm3.}, keywords = {}, pubstate = {published}, tppubtype = {article} } A printed wide-slot antenna with a centred rectangular parasitic patch, fed by a fork-like tuning stub with rectangular parasitic elements adjacent to the main feed line is proposed and discussed. The proposed wide-slot antenna eliminates the need of rotation of the slot and parasitic patches both in the ground plane for the improvement in impedance bandwidth. The experimental results indicate that the presented antenna has a bandwidth (-10 dB) of more than 148% ranging from 2 to 13.5 GHz. The total size of the proposed antenna configuration is 44.3 × 44.3 × 0.508 mm3. |
| 122. | Dong-Uk Sim; Jong-Hwa Kwon; Seong-Ook Park Design of electromagnetic wave absorber using periodic structure and method to broaden its bandwidth based on equivalent circuit-based analysis Journal Article IET Microwaves Antennas & Propagation, 9 , pp. 142 - 150, 2015. @article{Sim2015, title = {Design of electromagnetic wave absorber using periodic structure and method to broaden its bandwidth based on equivalent circuit-based analysis}, author = {Dong-Uk Sim and Jong-Hwa Kwon and Seong-Ook Park}, url = {http://143.248.148.42/wordpress/wp-content/uploads/2018/10/07027647.pdf}, doi = {10.1049/iet-map.2013.0487}, year = {2015}, date = {2015-02-05}, journal = {IET Microwaves Antennas & Propagation}, volume = {9}, pages = {142 - 150}, abstract = {A new broadband electromagnetic wave absorber based on a periodic surface and a method to increase its absorption bandwidth is proposed. The proposed absorber structure shows broadband characteristics, and its bandwidth is improved by generating additional resonances through a reasonable approach. To provide an understanding of the logical design procedure, an analytical method to determine the sheet resistance and new equivalent circuit models for analysing the impedance are both presented. From the analysis, it is shown that the exact range of the sheet resistance corresponding to the desired absorption level can be efficiently estimated for the resonance of the structure. For the verification of this approach to obtain an efficient design, as well as the functionality of both the absorber and the proposed method, experimental results are demonstrated along with analytical and computational results. The final measured results using the proposed method show a broadband reflectivity response, with a fractional bandwidth of approximately 93% below -10 dB and a bandwidth increase of 17%.}, keywords = {}, pubstate = {published}, tppubtype = {article} } A new broadband electromagnetic wave absorber based on a periodic surface and a method to increase its absorption bandwidth is proposed. The proposed absorber structure shows broadband characteristics, and its bandwidth is improved by generating additional resonances through a reasonable approach. To provide an understanding of the logical design procedure, an analytical method to determine the sheet resistance and new equivalent circuit models for analysing the impedance are both presented. From the analysis, it is shown that the exact range of the sheet resistance corresponding to the desired absorption level can be efficiently estimated for the resonance of the structure. For the verification of this approach to obtain an efficient design, as well as the functionality of both the absorber and the proposed method, experimental results are demonstrated along with analytical and computational results. The final measured results using the proposed method show a broadband reflectivity response, with a fractional bandwidth of approximately 93% below -10 dB and a bandwidth increase of 17%. |
| 121. | Chang-Hee Hyoung; Jung-Hwan Hwang; Sung-Wen Kang; Seong-Ook Park A Feasibility Study on the Adoption of Human Body Communication for Medical Service Journal Article IEEE Transactions on Circuits and Systems II: Express Briefs, 62 , pp. 169 - 173, 2015. @article{Hyoung2015, title = {A Feasibility Study on the Adoption of Human Body Communication for Medical Service}, author = {Chang-Hee Hyoung and Jung-Hwan Hwang and Sung-Wen Kang and Seong-Ook Park}, url = {http://143.248.148.42/wordpress/wp-content/uploads/2018/10/07001176.pdf}, doi = {10.1109/TCSII.2014.2387631}, year = {2015}, date = {2015-01-05}, journal = {IEEE Transactions on Circuits and Systems II: Express Briefs}, volume = {62}, pages = {169 - 173}, abstract = {A feasibility study on the adoption of human body communication (HBC) for medical service is presented. The electrical specifications of HBC for medical service were reviewed. The ratio of the leakage current into the heart to the output current of a capsule-type transmitter and the propagation loss in the channel were simulated using an anatomical body model. The in-body to on-body channel loss for HBC was provided by electromagnetic simulation from the capsule-type transmitter in the stomach to receiving electrodes on the abdominal region. An analog front end with a sensitivity of 37 μVpp was developed, which showed an improvement of 21 dB against the best report. The 14 mm × 26 mm capsule-type transmitter was implemented, and preclinical experiment was conducted using a live pig. The proposed system successfully transferred data from the capsule-type transmitter in a stomach to the electrodes on the butt and the low jaw of the pig at a high rate of 2 Mb/s at a distance of 90 cm without packet error.}, keywords = {}, pubstate = {published}, tppubtype = {article} } A feasibility study on the adoption of human body communication (HBC) for medical service is presented. The electrical specifications of HBC for medical service were reviewed. The ratio of the leakage current into the heart to the output current of a capsule-type transmitter and the propagation loss in the channel were simulated using an anatomical body model. The in-body to on-body channel loss for HBC was provided by electromagnetic simulation from the capsule-type transmitter in the stomach to receiving electrodes on the abdominal region. An analog front end with a sensitivity of 37 μVpp was developed, which showed an improvement of 21 dB against the best report. The 14 mm × 26 mm capsule-type transmitter was implemented, and preclinical experiment was conducted using a live pig. The proposed system successfully transferred data from the capsule-type transmitter in a stomach to the electrodes on the butt and the low jaw of the pig at a high rate of 2 Mb/s at a distance of 90 cm without packet error. |
2014 |
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| 120. | Jung-Hwan Hwang; Tae-Wook Kang; Youn-Tae Kim; Seong-Ook Park Empirical Channel Model for Human Body Communication Journal Article IEEE Antennas and Wireless Propagation Letters, 14 , pp. 694 - 697, 2014. @article{Hwang2014, title = {Empirical Channel Model for Human Body Communication}, author = {Jung-Hwan Hwang and Tae-Wook Kang and Youn-Tae Kim and Seong-Ook Park}, url = {http://143.248.148.42/wordpress/wp-content/uploads/2018/10/06975066.pdf}, doi = {10.1109/LAWP.2014.2377051}, year = {2014}, date = {2014-12-04}, journal = {IEEE Antennas and Wireless Propagation Letters}, volume = {14}, pages = {694 - 697}, abstract = {In this letter, an empirical channel model for human body communication (HBC) is presented based upon impulse response. For a channel model over a wide range of frequencies between 5 and 80 MHz, the amplitude of an impulse response is modeled with a random variable at each sampling point; the random variable is found using empirically obtained impulse responses with respect to multiple subjects of 70 human subjects. This empirical channel model is obtained when a signal transmitter and receiver are located on opposite hands. However, it provides a practical way to estimate the performance of HBC systems within an environment of multiple users and various devices.}, keywords = {}, pubstate = {published}, tppubtype = {article} } In this letter, an empirical channel model for human body communication (HBC) is presented based upon impulse response. For a channel model over a wide range of frequencies between 5 and 80 MHz, the amplitude of an impulse response is modeled with a random variable at each sampling point; the random variable is found using empirically obtained impulse responses with respect to multiple subjects of 70 human subjects. This empirical channel model is obtained when a signal transmitter and receiver are located on opposite hands. However, it provides a practical way to estimate the performance of HBC systems within an environment of multiple users and various devices. |
| 119. | Yun-Seok Noh; Rao Shahid Aziz; Myung-Hun Jeong; Dae-Hwan Jung; AK Ayra; Seong-Ook Park Rayleigh Fading Channel Characterization Using K-Band FMCW Radar in Reverberation Chamber Journal Article Progress In Electromagnetics Research M, 39 , pp. 193 - 201, 2014. @article{Noh2014, title = {Rayleigh Fading Channel Characterization Using K-Band FMCW Radar in Reverberation Chamber}, author = {Yun-Seok Noh and Rao Shahid Aziz and Myung-Hun Jeong and Dae-Hwan Jung and AK Ayra and Seong-Ook Park}, url = {http://143.248.148.42/wordpress/wp-content/uploads/2018/10/14102803.pdf}, doi = {10.2528/PIERM14102803}, year = {2014}, date = {2014-12-03}, journal = {Progress In Electromagnetics Research M}, volume = {39}, pages = {193 - 201}, abstract = {This paper investigates the channel characterization of Rayleigh fading channel using K-band frequency-modulated continuous wave (FMCW) radar system. An IF (intermediate frequency) signal of K-band FMCW radar can be treated as time and frequency domain signals due to a unique property of linear frequency modulation (LFM). First, channel sounder FMCW radar stability has been confirmed by measuring power flatness of transmitted radio frequency signal and estimated range in anechoic chamber before conducting the experiment for channel characterization of Rayleigh fading channel. Next, the measurement setup has been conducted in reverberation chamber which emulates multipath fading phenomena. In reverberation chamber, four different cases have been examined by changing the boundary conditions inside it with and without flat microwave absorbers. This investigation leads to obtained scattered plots, normalized propagation delay profiles (PDPs), mean excess delay, root-mean-square (RMS) delay spread and envelope distribution of Rayleigh fading channel at about 24.591 GHz.}, keywords = {}, pubstate = {published}, tppubtype = {article} } This paper investigates the channel characterization of Rayleigh fading channel using K-band frequency-modulated continuous wave (FMCW) radar system. An IF (intermediate frequency) signal of K-band FMCW radar can be treated as time and frequency domain signals due to a unique property of linear frequency modulation (LFM). First, channel sounder FMCW radar stability has been confirmed by measuring power flatness of transmitted radio frequency signal and estimated range in anechoic chamber before conducting the experiment for channel characterization of Rayleigh fading channel. Next, the measurement setup has been conducted in reverberation chamber which emulates multipath fading phenomena. In reverberation chamber, four different cases have been examined by changing the boundary conditions inside it with and without flat microwave absorbers. This investigation leads to obtained scattered plots, normalized propagation delay profiles (PDPs), mean excess delay, root-mean-square (RMS) delay spread and envelope distribution of Rayleigh fading channel at about 24.591 GHz. |
| 118. | Young-Guk Kim; Seong-Ook Park A wideband dual polarization base station antenna Journal Article Microwave and Optical Technology Letters, 57 , pp. 22 - 26, 2014. @article{Kim2014, title = {A wideband dual polarization base station antenna}, author = {Young-Guk Kim and Seong-Ook Park}, url = {http://143.248.148.42/wordpress/wp-content/uploads/2018/10/Kim_et_al-2015-Microwave_and_Optical_Technology_Letters.pdf}, doi = {doi.org/10.1002/mop.28767}, year = {2014}, date = {2014-11-18}, journal = {Microwave and Optical Technology Letters}, volume = {57}, pages = {22 - 26}, abstract = {This article investigates the slotted bow‐tie dual‐polarization antenna with achieving the wide band. The proposed antenna consists of upper antenna and lower antenna in one PCB substrate. This antenna achieves a −10 dB return loss within the operating band of 1.6–2.3 GHz, which has a 700 MHz bandwidth. Isolation between antenna 1 and antenna 2 is about −30 dB within the operating frequency band. Antenna 1 and 2's gains are above 8 dBi in the entire frequency bandwidth.}, keywords = {}, pubstate = {published}, tppubtype = {article} } This article investigates the slotted bow‐tie dual‐polarization antenna with achieving the wide band. The proposed antenna consists of upper antenna and lower antenna in one PCB substrate. This antenna achieves a −10 dB return loss within the operating band of 1.6–2.3 GHz, which has a 700 MHz bandwidth. Isolation between antenna 1 and antenna 2 is about −30 dB within the operating frequency band. Antenna 1 and 2's gains are above 8 dBi in the entire frequency bandwidth. |
| 117. | Viet-Anh Nguyen; Rao Shahid Aziz; Seong-Ook Park; Giwan Yoon A Design of Multiband, Dual-Polarization, Beam-Switchable Dual-antenna for Indoor Base Stations Journal Article Progress in Electromagnetics Research, 149 , pp. 147 - 160, 2014. @article{Nguyen2014b, title = {A Design of Multiband, Dual-Polarization, Beam-Switchable Dual-antenna for Indoor Base Stations}, author = {Viet-Anh Nguyen and Rao Shahid Aziz and Seong-Ook Park and Giwan Yoon}, url = {http://143.248.148.42/wordpress/wp-content/uploads/2018/10/14073103.pdf}, year = {2014}, date = {2014-10-14}, journal = {Progress in Electromagnetics Research}, volume = {149}, pages = {147 - 160}, abstract = {A novel multiband, dual-polarization, beam-switched dual-antenna design, covering some LTE and WLAN bands, has been proposed for indoor base stations. The proposed design consists mainly of dual modified monopole antennas. The horizontal antenna consists of four printed monopole elements, and the control circuit using p-i-n diodes has been implemented for feeding to each monopole element. The vertical monopole antenna beam patterns are controlled by reconfigurable frequency selective reflectors (RFSR) technique. The p-i-n diodes have been utilized for switching mechanism to feed the four RFSR. The measured and simulated results indicate that the antenna system possesses multiband and dual polarization. It has been observed from the simulated and measured reflection coefficients |S11| that the presented dual antenna system supports both LTE (1.7-2.1 GHz) and WLAN (2.5 GHz and 5.8 GHz) band frequencies. Moreover, the radiation characteristics show dual-polarization behaviors of the presented antenna system and beam switching states suitable for small cell indoor-base stations.}, keywords = {}, pubstate = {published}, tppubtype = {article} } A novel multiband, dual-polarization, beam-switched dual-antenna design, covering some LTE and WLAN bands, has been proposed for indoor base stations. The proposed design consists mainly of dual modified monopole antennas. The horizontal antenna consists of four printed monopole elements, and the control circuit using p-i-n diodes has been implemented for feeding to each monopole element. The vertical monopole antenna beam patterns are controlled by reconfigurable frequency selective reflectors (RFSR) technique. The p-i-n diodes have been utilized for switching mechanism to feed the four RFSR. The measured and simulated results indicate that the antenna system possesses multiband and dual polarization. It has been observed from the simulated and measured reflection coefficients |S11| that the presented dual antenna system supports both LTE (1.7-2.1 GHz) and WLAN (2.5 GHz and 5.8 GHz) band frequencies. Moreover, the radiation characteristics show dual-polarization behaviors of the presented antenna system and beam switching states suitable for small cell indoor-base stations. |
| 116. | Dohoon Kim; Hyo-J. Eom; Seong-Ook Park TM Modes on Pyramidal Transmission Line Journal Article IEEE Antennas and Wireless Propagation Letters, 13 , pp. 1741 - 1744, 2014. @article{Kim2014b, title = {TM Modes on Pyramidal Transmission Line}, author = {Dohoon Kim and Hyo-J. Eom and Seong-Ook Park }, url = {http://143.248.148.42/wordpress/wp-content/uploads/2018/10/06888463.pdf}, doi = {10.1109/LAWP.2014.2352674}, year = {2014}, date = {2014-08-29}, journal = {IEEE Antennas and Wireless Propagation Letters}, volume = {13}, pages = {1741 - 1744}, abstract = {Transverse magnetic (TM)-mode propagation on a pyramidal transmission line is considered. The mode-matching method is applied to study the TM-mode characteristics. A set of equations for modal coefficients is constituted and numerically solved. Field distributions of the TM modes are presented.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Transverse magnetic (TM)-mode propagation on a pyramidal transmission line is considered. The mode-matching method is applied to study the TM-mode characteristics. A set of equations for modal coefficients is constituted and numerically solved. Field distributions of the TM modes are presented. |
| 115. | Viet-Anh Nguyen; Byeong-Yong Park; Giwan Yoon; Seong-Ook Park A Planar Dipole for Multiband Antenna Systems With Self-Balanced Impedance Journal Article IEEE Antennas and Wireless Propagation Letters, 13 , pp. 1632 - 1635, 2014. @article{Nguyen2014, title = {A Planar Dipole for Multiband Antenna Systems With Self-Balanced Impedance}, author = {Viet-Anh Nguyen and Byeong-Yong Park and Giwan Yoon and Seong-Ook Park}, url = {http://143.248.148.42/wordpress/wp-content/uploads/2018/10/06878461.pdf}, doi = {10.1109/LAWP.2014.2347952}, year = {2014}, date = {2014-08-14}, journal = {IEEE Antennas and Wireless Propagation Letters}, volume = {13}, pages = {1632 - 1635}, abstract = {In this letter, we present a multiframe L-slot planar dipole loaded with a single microstripline for multiband antenna systems. The multiband is achieved by creating a multiframe L-slot on a host dipole and also by loading the host dipole antenna with a single microstripline to generate a couple of shunts and series of capacitive gaps with an inductive strip, eventually forming LC-like resonators. The antenna supports several wireless communication bands including: LTE bands at 1.7 ~ 1.8 and 2.3 ~ 2.6 GHz; WLAN bands at 2.4 ~ 2.5, 5.2, and 5.8 GHz; WiBro/WiMAX bands at 3 ~ 4 GHz. In addition, to validate the multiband behaviors, we also proposed a simple equivalent circuit for the designed antenna in which biconical transmission lines were adopted to model the host dipole sections. The simulation, fabrication, and measurement of the proposed antenna were implemented. As a result, its reflection coefficients |S11| were found to be better than -7 dB for most operating frequencies along with a sufficiently large bandwidth and good radiation patterns.}, keywords = {}, pubstate = {published}, tppubtype = {article} } In this letter, we present a multiframe L-slot planar dipole loaded with a single microstripline for multiband antenna systems. The multiband is achieved by creating a multiframe L-slot on a host dipole and also by loading the host dipole antenna with a single microstripline to generate a couple of shunts and series of capacitive gaps with an inductive strip, eventually forming LC-like resonators. The antenna supports several wireless communication bands including: LTE bands at 1.7 ~ 1.8 and 2.3 ~ 2.6 GHz; WLAN bands at 2.4 ~ 2.5, 5.2, and 5.8 GHz; WiBro/WiMAX bands at 3 ~ 4 GHz. In addition, to validate the multiband behaviors, we also proposed a simple equivalent circuit for the designed antenna in which biconical transmission lines were adopted to model the host dipole sections. The simulation, fabrication, and measurement of the proposed antenna were implemented. As a result, its reflection coefficients |S11| were found to be better than -7 dB for most operating frequencies along with a sufficiently large bandwidth and good radiation patterns. |
| 114. | Byeong-Yong Park; Myung-Hun Jeong; Seong-Ook Park A Magneto-Dielectric Handset Antenna for LTE/WWAN/GPS Applications Journal Article IEEE Antennas and Wireless Propagation Letters, 13 , pp. 1482 - 1485, 2014. @article{Park2014, title = {A Magneto-Dielectric Handset Antenna for LTE/WWAN/GPS Applications}, author = {Byeong-Yong Park and Myung-Hun Jeong and Seong-Ook Park}, url = {http://143.248.148.42/wordpress/wp-content/uploads/2018/10/06866129.pdf}, doi = {10.1109/LAWP.2014.2342256}, year = {2014}, date = {2014-07-25}, journal = {IEEE Antennas and Wireless Propagation Letters}, volume = {13}, pages = {1482 - 1485}, abstract = {A compact multiband internal antenna covering LTE/GSM/GPS/DCS/PCS/UMTS bands (748-960 and 1575.42-2690 MHz) is presented for mobile terminals. The antenna combines a coupled-fed scheme and a magneto-dielectric material, which has low loss properties (magnetic loss tangent ) up to 3 GHz, thereby achieving not only reduced antenna size but also improved bandwidth. In addition, a T-shaped monopole feeding line generating parasitic capacitance is applied to the proposed antenna. It plays an important role to shift the resonances, especially in the low band. The overall size of the antenna is only 35 ×15 ×4 mm 3 , corresponding to 0.0875λ0 ×0.0375 λ0 ×0.01 λ0 ( λ0 is the wavelength at 750 MHz). The design process and the measured results of the proposed antenna are presented in detail.}, keywords = {}, pubstate = {published}, tppubtype = {article} } A compact multiband internal antenna covering LTE/GSM/GPS/DCS/PCS/UMTS bands (748-960 and 1575.42-2690 MHz) is presented for mobile terminals. The antenna combines a coupled-fed scheme and a magneto-dielectric material, which has low loss properties (magnetic loss tangent ) up to 3 GHz, thereby achieving not only reduced antenna size but also improved bandwidth. In addition, a T-shaped monopole feeding line generating parasitic capacitance is applied to the proposed antenna. It plays an important role to shift the resonances, especially in the low band. The overall size of the antenna is only 35 ×15 ×4 mm 3 , corresponding to 0.0875λ0 ×0.0375 λ0 ×0.01 λ0 ( λ0 is the wavelength at 750 MHz). The design process and the measured results of the proposed antenna are presented in detail. |
| 113. | Byeong-Yong Park; Myung-Hun Jeong; Seong-Ook Park A Miniaturized Microstrip-to-Coplanar-Strip Transition Loaded with Artificial Transmission Lines and 2.4-GHz Antenna Application Journal Article IEEE Antennas and Wireless Propagation Letters, 13 , pp. 1486 - 1489, 2014. @article{Park2014b, title = {A Miniaturized Microstrip-to-Coplanar-Strip Transition Loaded with Artificial Transmission Lines and 2.4-GHz Antenna Application}, author = {Byeong-Yong Park and Myung-Hun Jeong and Seong-Ook Park}, url = {http://143.248.148.42/wordpress/wp-content/uploads/2018/10/06861938.pdf}, doi = {10.1109/LAWP.2014.2341552}, year = {2014}, date = {2014-07-22}, journal = {IEEE Antennas and Wireless Propagation Letters}, volume = {13 }, pages = {1486 - 1489}, abstract = {A miniaturized microstrip-to-coplanar strip transition and its antenna application are presented in this letter. A composite right/left-handed transmission line and planar artificial transmission lines are used to design the transition in the 2.4-GHz band and to balance the output of the transition over a wider frequency range. In addition, the occupied area of the transition is only 0.087λg 2 . The 3-dB back-to-back insertion loss bandwidth is around 84%. Based on the proposed transition, a quasi-Yagi antenna is demonstrated. The impedance bandwidth is 30.3%. The antenna offers excellent endfire radiation performance. The maximum gain and front-to-back ratio are 5.1 dBi and 21 dB, respectively, at the endfire direction in the operating band. The design process and the measured results of the proposed design are presented in detail.}, keywords = {}, pubstate = {published}, tppubtype = {article} } A miniaturized microstrip-to-coplanar strip transition and its antenna application are presented in this letter. A composite right/left-handed transmission line and planar artificial transmission lines are used to design the transition in the 2.4-GHz band and to balance the output of the transition over a wider frequency range. In addition, the occupied area of the transition is only 0.087λg 2 . The 3-dB back-to-back insertion loss bandwidth is around 84%. Based on the proposed transition, a quasi-Yagi antenna is demonstrated. The impedance bandwidth is 30.3%. The antenna offers excellent endfire radiation performance. The maximum gain and front-to-back ratio are 5.1 dBi and 21 dB, respectively, at the endfire direction in the operating band. The design process and the measured results of the proposed design are presented in detail. |
| 112. | Yun-Taek Im; Maifuz Ali; Seong-Ook Park Slow Modulation Behavior of the FMCW Radar for Wireless Channel Sounding Technology Journal Article IEEE Transactions on Electromagnetic Compatibility, 56 , pp. 1229 - 1237, 2014. @article{Im2014c, title = {Slow Modulation Behavior of the FMCW Radar for Wireless Channel Sounding Technology}, author = {Yun-Taek Im and Maifuz Ali and Seong-Ook Park}, url = {http://143.248.148.42/wordpress/wp-content/uploads/2018/10/06804658.pdf}, doi = {10.1109/TEMC.2014.2311095}, year = {2014}, date = {2014-04-23}, journal = {IEEE Transactions on Electromagnetic Compatibility}, volume = {56}, pages = {1229 - 1237}, abstract = {A frequency-modulated continuous wave (FMCW) radar is used to sounding wireless channel. An intermediate frequency signal of the FMCW radar can be treated simultaneously as a frequency-domain signal as well as a time-domain signal when the modulation time is sufficiently long. This distinctive compatibility enables the FMCW radar system to measure the normalized impulse response for the power delay profile and Rician K-factor by using an oscilloscope. This theory is fully demonstrated and experiments are performed in the reverberation chamber for the small-scale fading environments of Rayleigh and Rician conditions, and all measurements are verified by using the oscilloscope.}, keywords = {}, pubstate = {published}, tppubtype = {article} } A frequency-modulated continuous wave (FMCW) radar is used to sounding wireless channel. An intermediate frequency signal of the FMCW radar can be treated simultaneously as a frequency-domain signal as well as a time-domain signal when the modulation time is sufficiently long. This distinctive compatibility enables the FMCW radar system to measure the normalized impulse response for the power delay profile and Rician K-factor by using an oscilloscope. This theory is fully demonstrated and experiments are performed in the reverberation chamber for the small-scale fading environments of Rayleigh and Rician conditions, and all measurements are verified by using the oscilloscope. |
| 111. | Dong-Hun Shin; Ki-Beom Kim; Jong-Guk Kim; Seong-Ook Park Design of Null-Filling Antenna for Automotive Radar Using the Genetic Algorithm Journal Article IEEE Antennas and Wireless Propagation Letters, 13 , pp. 738 - 741, 2014. @article{Shin2014, title = {Design of Null-Filling Antenna for Automotive Radar Using the Genetic Algorithm}, author = {Dong-Hun Shin and Ki-Beom Kim and Jong-Guk Kim and Seong-Ook Park}, url = {http://143.248.148.42/wordpress/wp-content/uploads/2018/10/06785956.pdf}, doi = {10.1109/LAWP.2014.2316300}, year = {2014}, date = {2014-04-09}, journal = {IEEE Antennas and Wireless Propagation Letters}, volume = {13}, pages = {738 - 741}, abstract = {A null-filling antenna for automotive radar is investigated using the genetic algorithm. The single column of the proposed antenna consists of four gap-coupled antenna elements and 14 direct-coupled antenna elements. The radiating elements are inclined 45 ° from the feedline. The proposed antenna has 19.67 dBi gain with a -20.19-dB sidelobe level in the elevation and a -25.08-dB sidelobe level in the azimuth direction. The blind zone is reduced from 19.03 to 2.38 m using the proposed antenna for sensing the obstacle. The proposed antenna is a good solution for both short- and long-range automotive radar.}, keywords = {}, pubstate = {published}, tppubtype = {article} } A null-filling antenna for automotive radar is investigated using the genetic algorithm. The single column of the proposed antenna consists of four gap-coupled antenna elements and 14 direct-coupled antenna elements. The radiating elements are inclined 45 ° from the feedline. The proposed antenna has 19.67 dBi gain with a -20.19-dB sidelobe level in the elevation and a -25.08-dB sidelobe level in the azimuth direction. The blind zone is reduced from 19.03 to 2.38 m using the proposed antenna for sensing the obstacle. The proposed antenna is a good solution for both short- and long-range automotive radar. |
| 110. | Myung-Hun Jeong; Byeong-Yong Park; Jung-Hwan Choi; Seong-Ook Park Doppler Spread Spectrum of a Circularly Moving Receiver in an Anechoic and a Reverberation Chamber Journal Article Progress In Electromagnetics Research C, 48 , pp. 125 - 132, 2014. @article{Jeong2014, title = {Doppler Spread Spectrum of a Circularly Moving Receiver in an Anechoic and a Reverberation Chamber}, author = {Myung-Hun Jeong and Byeong-Yong Park and Jung-Hwan Choi and Seong-Ook Park}, url = {http://143.248.148.42/wordpress/wp-content/uploads/2018/10/13122601.pdf}, doi = {10.2528/PIERC13122601}, year = {2014}, date = {2014-03-18}, journal = {Progress In Electromagnetics Research C}, volume = {48}, pages = {125 - 132}, abstract = {The Doppler phenomena caused by a moving receiver or environmental scatters around a receiver are emulated in an AC(Anechoic Chamber) and a RC(Reverberation Chamber) using platform and mode stirring. In order to verify the emulated Doppler spread spectrum, the measured results in the AC and the RC have been investigated to incorporate Jakes's and 802.11 TGn Doppler models, respectively.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The Doppler phenomena caused by a moving receiver or environmental scatters around a receiver are emulated in an AC(Anechoic Chamber) and a RC(Reverberation Chamber) using platform and mode stirring. In order to verify the emulated Doppler spread spectrum, the measured results in the AC and the RC have been investigated to incorporate Jakes's and 802.11 TGn Doppler models, respectively. |
| 109. | Viet-Anh Nguyen; Rao Shahid Aziz; Seong-Ook Park Multi-band, Dual Polarization, Dual Antennas for Beam Reconfigurable Antenna System for Small Cell Base Station (Invited Paper) Journal Article 2014 International Workshop on Antenna Technology: Small Antennas, Novel EM Structures and Materials, and Applications (iWAT), 2014. @article{Nguyen2014c, title = {Multi-band, Dual Polarization, Dual Antennas for Beam Reconfigurable Antenna System for Small Cell Base Station (Invited Paper)}, author = {Viet-Anh Nguyen and Rao Shahid Aziz and Seong-Ook Park}, url = {http://143.248.148.42/wordpress/wp-content/uploads/2018/10/06958625.pdf}, year = {2014}, date = {2014-03-04}, journal = {2014 International Workshop on Antenna Technology: Small Antennas, Novel EM Structures and Materials, and Applications (iWAT)}, abstract = {Multiband, dual polarization dual antennas for beam reconfigurable antenna system suitable for small cell indoor wireless base stations is proposed. The whole design consists of horizontal and vertical antennas on a PCB board. Both the antennas are printed monopole type. The antenna supports LTE (1.7-2.1 GHz) and WLAN (2.5 GHz and 5.75 GHz) band frequencies. The simulated reflection coefficients |S 11 | of the proposed antenna shows that at operating frequencies undergo sufficient bandwidth lower than -7dB. Additionally, radiation characteristic of the presented antenna shows dual polarization behavior and switching states of the beam.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Multiband, dual polarization dual antennas for beam reconfigurable antenna system suitable for small cell indoor wireless base stations is proposed. The whole design consists of horizontal and vertical antennas on a PCB board. Both the antennas are printed monopole type. The antenna supports LTE (1.7-2.1 GHz) and WLAN (2.5 GHz and 5.75 GHz) band frequencies. The simulated reflection coefficients |S 11 | of the proposed antenna shows that at operating frequencies undergo sufficient bandwidth lower than -7dB. Additionally, radiation characteristic of the presented antenna shows dual polarization behavior and switching states of the beam. |
| 108. | Dong-Uk Sim; Jung-Ick Moon; Seong-Ook Park An internal triple-band antenna for PCS/IMT-2000/Bluetooth applications Journal Article IEEE Antennas and Wireless Propagation Letters, 3 , 2014. @article{Sim2014b, title = {An internal triple-band antenna for PCS/IMT-2000/Bluetooth applications}, author = {Dong-Uk Sim and Jung-Ick Moon and Seong-Ook Park}, url = {http://143.248.148.42/wordpress/wp-content/uploads/2018/10/01290930.pdf}, doi = {10.1109/LAWP.2004.827903}, year = {2014}, date = {2014-02-01}, journal = {IEEE Antennas and Wireless Propagation Letters}, volume = {3}, abstract = {An internal triple-band antenna fed by a microstrip line is proposed for operation in the PCS, IMT-2000, and Bluetooth bands. By using two branches of meander line, the desired resonant frequencies can be achieved. A broadband characteristic for each band is optimized by tuning the parts of the radiating patch and the size of each strip line segment. The proposed antenna and substrate are small enough to be built in a practical mobile handset. Details of the proposed technique and experimental results are presented and discussed.}, keywords = {}, pubstate = {published}, tppubtype = {article} } An internal triple-band antenna fed by a microstrip line is proposed for operation in the PCS, IMT-2000, and Bluetooth bands. By using two branches of meander line, the desired resonant frequencies can be achieved. A broadband characteristic for each band is optimized by tuning the parts of the radiating patch and the size of each strip line segment. The proposed antenna and substrate are small enough to be built in a practical mobile handset. Details of the proposed technique and experimental results are presented and discussed. |
2013 |
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| 107. | Sang-Jin Eom; Ho-Saeng Kim; Maifuz Ali; Seong-Ook Park Embedded Antenna for Metallic Handheld Communication Devices Journal Article Progress In Electromagnetics Research B, 57 , pp. 127 - 138, 2013. @article{Eom2013, title = {Embedded Antenna for Metallic Handheld Communication Devices}, author = {Sang-Jin Eom and Ho-Saeng Kim and Maifuz Ali and Seong-Ook Park}, url = {http://143.248.148.42/wordpress/wp-content/uploads/2018/10/13101107.pdf}, year = {2013}, date = {2013-12-03}, journal = {Progress In Electromagnetics Research B}, volume = {57}, pages = {127 - 138}, abstract = {In this study, a quad-band folded slot antenna with a monopole feed line embedded in a conductive housing structure (the LCD bracket of a mobile phone) is proposed. The performance of the proposed antenna is evaluated through simulation and measurement, demonstrating that it can provide total radiation efficiencies of more than 40% in the EGSM900, DCS, PCS, and WCDMA1 bands. Over these four bands, the total radiated power (TRP) of a prototype mobile phone using the antenna is 28.5, 27.1, 27.5, and 21 dBm, respectively, while the total isotropic sensitivity (TIS) is 102.7, 104.3, 103.8, and 107.3 dBm, respectively; all of these values satisfy Cellular Telecommunication and Internet Association (CTIA) requirements for over-the-area-(OTA) testing standards. The radiation performance of the proposed antenna in the calling mode is tested and shown to be within satisfactory limits; similarly, the specific absorption rates (SARs) of the prototype mobile phone are also found to be within standard SAR limits.}, keywords = {}, pubstate = {published}, tppubtype = {article} } In this study, a quad-band folded slot antenna with a monopole feed line embedded in a conductive housing structure (the LCD bracket of a mobile phone) is proposed. The performance of the proposed antenna is evaluated through simulation and measurement, demonstrating that it can provide total radiation efficiencies of more than 40% in the EGSM900, DCS, PCS, and WCDMA1 bands. Over these four bands, the total radiated power (TRP) of a prototype mobile phone using the antenna is 28.5, 27.1, 27.5, and 21 dBm, respectively, while the total isotropic sensitivity (TIS) is 102.7, 104.3, 103.8, and 107.3 dBm, respectively; all of these values satisfy Cellular Telecommunication and Internet Association (CTIA) requirements for over-the-area-(OTA) testing standards. The radiation performance of the proposed antenna in the calling mode is tested and shown to be within satisfactory limits; similarly, the specific absorption rates (SARs) of the prototype mobile phone are also found to be within standard SAR limits. |
| 106. | Yun-Taek Im; Seong-Ook Park An FMCW and chirp pulse-doppler radar system for surveillance in X-band Journal Article Microwave and Optical Technology Letters, 55 , pp. 474 - 479, 2013. @article{Im2013, title = {An FMCW and chirp pulse-doppler radar system for surveillance in X-band}, author = {Yun-Taek Im and Seong-Ook Park}, url = {http://143.248.148.42/wordpress/wp-content/uploads/2018/10/Im_et_al-2013-Microwave_and_Optical_Technology_Letters.pdf}, doi = {10.1002/mop.27343}, year = {2013}, date = {2013-01-28}, journal = {Microwave and Optical Technology Letters}, volume = {55}, pages = {474 - 479}, abstract = {A narrow band radar system based on a field programmable gate array is proposed for dual‐mode operation.Frequency‐modulated continuous‐wave (FMCW) radar mode is for short‐range target detection and pulse‐Doppler (PD) radar mode is for long‐range target detection. Precomputed codes are used to generate linear frequency modulation signals in both FMCW and PD radar mode. The bandwidths of FMCW and PD radar modes are 10 and 1 MHz. Experiments have been carried out to confirm the system operation. In FMCW radar mode, nonlinear amplitude response can be corrected by precomputed code. In PD radar mode, the RX signals have been checked in the pulse width of 4 μs with a compressed echo signal response.}, keywords = {}, pubstate = {published}, tppubtype = {article} } A narrow band radar system based on a field programmable gate array is proposed for dual‐mode operation.Frequency‐modulated continuous‐wave (FMCW) radar mode is for short‐range target detection and pulse‐Doppler (PD) radar mode is for long‐range target detection. Precomputed codes are used to generate linear frequency modulation signals in both FMCW and PD radar mode. The bandwidths of FMCW and PD radar modes are 10 and 1 MHz. Experiments have been carried out to confirm the system operation. In FMCW radar mode, nonlinear amplitude response can be corrected by precomputed code. In PD radar mode, the RX signals have been checked in the pulse width of 4 μs with a compressed echo signal response. |
2012 |
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| 105. | Han-Cheol Ryu; Seong-Ook Park; Kwang-Yong Kang A spectral analysis of an integrated photomixer/antenna in a homodyne terahertz photomixing system Journal Article Optics Communications, 286 , pp. 363 - 367, 2012. @article{Ryu2012, title = {A spectral analysis of an integrated photomixer/antenna in a homodyne terahertz photomixing system}, author = {Han-Cheol Ryu and Seong-Ook Park and Kwang-Yong Kang}, url = {http://143.248.148.42/wordpress/wp-content/uploads/2018/10/1-s2.0-S0030401812009984-main.pdf}, doi = {10.1016/j.optcom.2012.09.021}, year = {2012}, date = {2012-09-28}, journal = {Optics Communications}, volume = {286}, pages = {363 - 367}, abstract = {An analysis has been carried out to estimate the spectral characteristics of an integrated photomixer/antenna in a homodyne photomixing system. The analysis adopts the impedance mismatch factor and Friis power transmission formula used in communication links based on the conventional analysis theory of a terahertz photomixer. The analysis and experimental results have proved that an impedance matching condition between the impedance of a photomixer and the input impedance of an antenna is directly related with photomixing terahertz wave generation. The Friis formula is introduced to calculate the propagation loss of the wave from a transmitter to a receiver in a homodyne photomixing system. A log-periodic antenna was used to ensure a high dynamic range in a broad frequency region. The dynamic range of the homodyne terahertz photomixing system was about 60 dB near 100 GHz and decreased with an increasing frequency from 10 GHz to 1000 GHz. The measured results agree well with the theoretically analyzed results and prove that the terahertz photomixing power is closely related to impedance mismatch factor and it could be estimated in the homodyne terahertz photomixing system without a terahertz power detector.}, keywords = {}, pubstate = {published}, tppubtype = {article} } An analysis has been carried out to estimate the spectral characteristics of an integrated photomixer/antenna in a homodyne photomixing system. The analysis adopts the impedance mismatch factor and Friis power transmission formula used in communication links based on the conventional analysis theory of a terahertz photomixer. The analysis and experimental results have proved that an impedance matching condition between the impedance of a photomixer and the input impedance of an antenna is directly related with photomixing terahertz wave generation. The Friis formula is introduced to calculate the propagation loss of the wave from a transmitter to a receiver in a homodyne photomixing system. A log-periodic antenna was used to ensure a high dynamic range in a broad frequency region. The dynamic range of the homodyne terahertz photomixing system was about 60 dB near 100 GHz and decreased with an increasing frequency from 10 GHz to 1000 GHz. The measured results agree well with the theoretically analyzed results and prove that the terahertz photomixing power is closely related to impedance mismatch factor and it could be estimated in the homodyne terahertz photomixing system without a terahertz power detector. |
| 104. | Manh-Tuan Dao; Dong-Hun Shin; Yun-Taek Im; Seong-Ook Park A two sweeping VCO source for heterodyne FMCW radar Journal Article IEEE Transactions on Instrumentation and measurement, pp. 230 - 239, 2012. @article{Dao2012, title = {A two sweeping VCO source for heterodyne FMCW radar}, author = {Manh-Tuan Dao and Dong-Hun Shin and Yun-Taek Im and Seong-Ook Park}, url = {http://143.248.148.42/wordpress/wp-content/uploads/2018/10/06304920.pdf}, doi = {10.1109/TIM.2012.2212510}, year = {2012}, date = {2012-09-17}, journal = {IEEE Transactions on Instrumentation and measurement}, pages = {230 - 239}, abstract = {We propose and develop a heterodyne frequency modulated continuous wave (FMCW) radar system. The system operates at 14 GHz with a 500-MHz bandwidth in a 100-μs sweeping period, based on two wideband linear RF voltage-controlled oscillator (VCO) sweeping sources, which are controlled by a direct digital synthesizer (DDS) through a phase-locked scheme, leading to a high linearity of the frequency chirping signal. To achieve low phase noise, the RF signals are synthesized from low-noise baseband signals which are generated through a generation scheme of using phase-locked oscillators operating in the 800-MHz frequency range. Additionally, the proposed architecture can eliminate the phase noise contributions and/or frequency deviation due to the uncorrelation of different VCOs. The results are verified through measurements and derivation.}, keywords = {}, pubstate = {published}, tppubtype = {article} } We propose and develop a heterodyne frequency modulated continuous wave (FMCW) radar system. The system operates at 14 GHz with a 500-MHz bandwidth in a 100-μs sweeping period, based on two wideband linear RF voltage-controlled oscillator (VCO) sweeping sources, which are controlled by a direct digital synthesizer (DDS) through a phase-locked scheme, leading to a high linearity of the frequency chirping signal. To achieve low phase noise, the RF signals are synthesized from low-noise baseband signals which are generated through a generation scheme of using phase-locked oscillators operating in the 800-MHz frequency range. Additionally, the proposed architecture can eliminate the phase noise contributions and/or frequency deviation due to the uncorrelation of different VCOs. The results are verified through measurements and derivation. |
| 103. | Viet-Anh Nguyen; Myung-Hun Jeong; Manh-Tuan Dao; Seong-Ook Park Four-port Beam Reconfigurable Antenna Array for Pattern Diversity System Journal Article IET Microwaves, Antennas & Propagation, 6 , pp. 1179 - 1186, 2012. @article{Nguyen2012, title = {Four-port Beam Reconfigurable Antenna Array for Pattern Diversity System}, author = {Viet-Anh Nguyen and Myung-Hun Jeong and Manh-Tuan Dao and Seong-Ook Park}, url = {http://143.248.148.42/wordpress/wp-content/uploads/2018/10/06270166.pdf}, doi = {10.1049/iet-map.2011.0606}, year = {2012}, date = {2012-08-20}, journal = {IET Microwaves, Antennas & Propagation}, volume = {6}, pages = {1179 - 1186}, abstract = {This study investigates a practical design for a switched beam planar antenna that can be implemented as a compact, low-cost switchable and/or reconfigurable beam antenna array. The antenna consists of a four-port antenna array, which is based on L-shaped quarter-wavelength slot antenna elements. This type of antenna array is a planar structure and its maximum directional radiation beam pattern presents in an azimuth plane covering 3600. The antenna array operates based on the `ON' or `OFF' states of PIN diodes in each individual slot antenna element and the combined signals from the four-port output. Therefore by properly controlling the state of the PIN diodes, the antenna exposes its characteristics of switchable/ reconfigurable beam patterns in the Φ-plane. To validate the proposed design, a small smart, switched-beam antenna operating at 2.7 GHz in multiple input-multiple output applications is simulated and fabricated.}, keywords = {}, pubstate = {published}, tppubtype = {article} } This study investigates a practical design for a switched beam planar antenna that can be implemented as a compact, low-cost switchable and/or reconfigurable beam antenna array. The antenna consists of a four-port antenna array, which is based on L-shaped quarter-wavelength slot antenna elements. This type of antenna array is a planar structure and its maximum directional radiation beam pattern presents in an azimuth plane covering 3600. The antenna array operates based on the `ON' or `OFF' states of PIN diodes in each individual slot antenna element and the combined signals from the four-port output. Therefore by properly controlling the state of the PIN diodes, the antenna exposes its characteristics of switchable/ reconfigurable beam patterns in the Φ-plane. To validate the proposed design, a small smart, switched-beam antenna operating at 2.7 GHz in multiple input-multiple output applications is simulated and fabricated. |
| 102. | Soon-Gyu Yi; Ki-Bok Kong; Byeong-Yong Park; Maifuz Ali; Seong-Ook Park Modeling and Performance Analysis of Reverberation Chamber using FDTD Method Journal Article IET Microwave Antennas and propagation, 6 , pp. 975 - 981, 2012. @article{Yi2012, title = {Modeling and Performance Analysis of Reverberation Chamber using FDTD Method}, author = {Soon-Gyu Yi and Ki-Bok Kong and Byeong-Yong Park and Maifuz Ali and Seong-Ook Park}, url = {http://143.248.148.42/wordpress/wp-content/uploads/2018/10/06248280.pdf}, doi = {10.1049/iet-map.2011.0612}, year = {2012}, date = {2012-07-26}, journal = {IET Microwave Antennas and propagation}, volume = {6}, pages = {975 - 981}, abstract = {A reverberation chamber (RC) is modelled using a finite-difference time-domain (FDTD) method. To evaluate the performance, firstly, the electric field distribution and then the spatial correlation are computed inside the chamber using the FDTD method. In this work, dipole antennas operating at 750 MHz are used in transmitting and receiving mode. Empirical cumulative distribution functions obtained from FDTD simulations and measured S21 are compared with the Rayleigh distribution. The spatial correlation of the electric field inside the RC is computed from the FDTD-simulated and measured results and compared with published correlation functions.}, keywords = {}, pubstate = {published}, tppubtype = {article} } A reverberation chamber (RC) is modelled using a finite-difference time-domain (FDTD) method. To evaluate the performance, firstly, the electric field distribution and then the spatial correlation are computed inside the chamber using the FDTD method. In this work, dipole antennas operating at 750 MHz are used in transmitting and receiving mode. Empirical cumulative distribution functions obtained from FDTD simulations and measured S21 are compared with the Rayleigh distribution. The spatial correlation of the electric field inside the RC is computed from the FDTD-simulated and measured results and compared with published correlation functions. |
| 101. | Ki-Bok Kong; Seong-Ook Park Stability and Numerical Dispersion of 3-D Simplified Sampling Biorthogonal ADI Method Journal Article Journal of Electromagnetic Waves and Applications, 24 , pp. 1 - 12, 2012. @article{Kong2012, title = {Stability and Numerical Dispersion of 3-D Simplified Sampling Biorthogonal ADI Method}, author = {Ki-Bok Kong and Seong-Ook Park}, url = {http://143.248.148.42/wordpress/wp-content/uploads/2018/10/Stability.pdf}, doi = {10.1163/156939310790322136}, year = {2012}, date = {2012-04-03}, journal = {Journal of Electromagnetic Waves and Applications}, volume = {24}, pages = {1 - 12}, abstract = {We previously introduced the simplified sampling biorthogonal direction implicit (SSB-ADI) method for 2-D Maxwell's equations. This paper extends it to a 3-D SSB-ADI method. Similar to the original method, the 3-D SSB-ADI method also partially uses the sampling property and compact support of the SBTD algorithm to display spatial discretization. Dispersion and stability analysis are presented. A numerical example shows that the SSB-ADI method is superior to the SB-ADI method in terms of reducing the CPU time and memory requirement of the numerical simulation.}, keywords = {}, pubstate = {published}, tppubtype = {article} } We previously introduced the simplified sampling biorthogonal direction implicit (SSB-ADI) method for 2-D Maxwell's equations. This paper extends it to a 3-D SSB-ADI method. Similar to the original method, the 3-D SSB-ADI method also partially uses the sampling property and compact support of the SBTD algorithm to display spatial discretization. Dispersion and stability analysis are presented. A numerical example shows that the SSB-ADI method is superior to the SB-ADI method in terms of reducing the CPU time and memory requirement of the numerical simulation. |
| 100. | Chang-Hee Hyoung; Sung-Weon Kang; Youn-Tae Kim; Seong-Ook Park Transceiver for Human Body Communication Using Frequency Selective Digital Transmission Journal Article ETRI Journal, 34 , pp. 216 - 225, 2012. @article{Hyoung2012, title = {Transceiver for Human Body Communication Using Frequency Selective Digital Transmission}, author = {Chang-Hee Hyoung and Sung-Weon Kang and Youn-Tae Kim and Seong-Ook Park}, url = {http://143.248.148.42/wordpress/wp-content/uploads/2018/10/etrij.12.0111.0178.pdf}, doi = {10.4218/etrij.12.0111.0178}, year = {2012}, date = {2012-04-01}, journal = {ETRI Journal}, volume = {34}, pages = {216 - 225}, abstract = {This paper presents a transceiver module for human body communications whereby a spread signal with a group of 64 Walsh codes is directly transferred through a human body at a chip rate of 32 Mcps. Frequency selective digital transmission moves the signal spectrum over 5 MHz without continuous frequency modulation and increases the immunity to induced interference by the processing gain. A simple receiver structure with no additional analog circuitry for the transmitter has been developed and has a sensitivity of 250 µVpp. The high sensitivity of the receiver makes it possible to communicate between mobile devices using a human body as the transmission medium. It enables half‐duplex communication of 2 Mbps within an operating range of up to 170 cm between the ultra‐mobile PCs held between fingertips of each hand with a packet error rate of lower than 10−6. The transceiver module consumes 59 mA with a 3.3 V power supply.}, keywords = {}, pubstate = {published}, tppubtype = {article} } This paper presents a transceiver module for human body communications whereby a spread signal with a group of 64 Walsh codes is directly transferred through a human body at a chip rate of 32 Mcps. Frequency selective digital transmission moves the signal spectrum over 5 MHz without continuous frequency modulation and increases the immunity to induced interference by the processing gain. A simple receiver structure with no additional analog circuitry for the transmitter has been developed and has a sensitivity of 250 µVpp. The high sensitivity of the receiver makes it possible to communicate between mobile devices using a human body as the transmission medium. It enables half‐duplex communication of 2 Mbps within an operating range of up to 170 cm between the ultra‐mobile PCs held between fingertips of each hand with a packet error rate of lower than 10−6. The transceiver module consumes 59 mA with a 3.3 V power supply. |
| 99. | Byung-Chan Kim; Jae-Hoon Yun; Seong-Ook Park Uncertainty Estimation for Evaluating Human Exposure Levels to RF Electromagnetic Fields from Cellular Base Stations Journal Article IEEE Transactions on Electromagnetic Compatibility, 54 , pp. 246 - 253, 2012. @article{Kim2012, title = {Uncertainty Estimation for Evaluating Human Exposure Levels to RF Electromagnetic Fields from Cellular Base Stations}, author = {Byung-Chan Kim and Jae-Hoon Yun and Seong-Ook Park}, url = {http://143.248.148.42/wordpress/wp-content/uploads/2018/10/06142059-1.pdf}, doi = {10.1109/TEMC.2012.2182768}, year = {2012}, date = {2012-01-31}, journal = {IEEE Transactions on Electromagnetic Compatibility}, volume = {54}, pages = {246 - 253}, abstract = {This paper investigates the estimation of uncertainty when evaluating the levels of human exposure to electromagnetic fields radiated from cellular base stations which aim to verify the exposure compliance with human protection guidelines. Uncertainty should be provided when publishing the results of an evaluation since measured physical quantities are not complete unless they are accompanied by some indication of their reliability. In this study, uncertainty sources are classified into four groups: physical parameters, mechanical constraints, postprocessing, and measurement equipment. Type A standard uncertainties are obtained from repeated observations by in situ measurement around cellular base stations, and they include uncertainties introduced by sources other than measurement equipment. Type B uncertainties are determined from the calibration data offered by measurement equipment manufacturers. The estimated overall uncertainty is ±3.82 dB.}, keywords = {}, pubstate = {published}, tppubtype = {article} } This paper investigates the estimation of uncertainty when evaluating the levels of human exposure to electromagnetic fields radiated from cellular base stations which aim to verify the exposure compliance with human protection guidelines. Uncertainty should be provided when publishing the results of an evaluation since measured physical quantities are not complete unless they are accompanied by some indication of their reliability. In this study, uncertainty sources are classified into four groups: physical parameters, mechanical constraints, postprocessing, and measurement equipment. Type A standard uncertainties are obtained from repeated observations by in situ measurement around cellular base stations, and they include uncertainties introduced by sources other than measurement equipment. Type B uncertainties are determined from the calibration data offered by measurement equipment manufacturers. The estimated overall uncertainty is ±3.82 dB. |