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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
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The Journal of Korean Institute of Electromagnetic Engineering and Science
Journal Basic Information
Journal DOI :
The Korean Institute of Electromagnetic Engineering and Science
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Volume & Issues
Volume 22, Issue 12 - Dec 2011
Volume 22, Issue 11 - Nov 2011
Volume 22, Issue 10 - Oct 2011
Volume 22, Issue 9 - Sep 2011
Volume 22, Issue 8 - Aug 2011
Volume 22, Issue 7 - Jul 2011
Volume 22, Issue 6 - Jun 2011
Volume 22, Issue 5 - May 2011
Volume 22, Issue 4 - Apr 2011
Volume 22, Issue 3 - Mar 2011
Volume 22, Issue 2 - Feb 2011
Volume 22, Issue 1 - Jan 2011
Selecting the target year
Design of Contactless Power Transmission Device Using Cavity Resonator
Chang, Tae-Soon ; Kim, Yong-Nam ; Hur, Jung ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 22, issue 11, 2011, Pages 1025~1033
DOI : 10.5515/KJKIEES.2011.22.11.1025
In this paper, we introduce the contactless power transmission device for transmitting the power with the resonant characteristic of the cavity resonator. When transmitting the power, the contactless power transmission device begins to work in the condition where the transceiver adheres closely. The transceiver is electrically separated because there is no conductive terminal outside and the size of the receiver required for the electric power transmission can be minimized. The cavity resonator comprises slots for the input port and output port in the upper side conductor plate of the cavity and forms the input port and output port using the stripline structure at this upper part. The some of output port is separated from it and the electric power receiver is formed thus the union can be possible. The rest except electric power receiver become the electric power transmitter, which includes the input port of stripline-slot coupling, cavity, and the slot of the output port. If the transmitter and the receiver are combined, they become the form in which the electricity is transferred from the input port to the output port in a cavity resonator. The center frequency of the contactless power transmitter manufactured is 5.782 GHz. and
is measured as -1.07 dB. It is confirmed that the high electric power transfer rate is approximately 78 %.
Design of X-band 40 W Pulse-Driven GaN HEMT Power Amplifier Using Load-Pull Measurement with Pre-matched Fixture
Jeong, Hae-Chang ; Oh, Hyun-Seok ; Yeom, Kyung-Whan ; Jin, Hyeong-Seok ; Park, Jong-Sul ; Jang, Ho-Ki ; Kim, Bo-Kyun ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 22, issue 11, 2011, Pages 1034~1046
DOI : 10.5515/KJKIEES.2011.22.11.1034
In this paper, a design and fabrication of 40 W power amplifier for the X-band using load-pull measurement of GaN HEMT chip are presented. The adopted active device for power amplifier is GaN HEMT chip of TriQuint company, which is recently released. Pre-matched fixtures are designed in test jig, because the impedance range of load-pull tuner is limited at measuring frequency. Essentially required 2-port S-parameters of the fixtures for extraction optimal input and output impedances is obtained by the presented newly method. The method is verified in comparison of the extracted optimal impedances with data sheet. The impedance matching circuit for power amplifier is designed based on EM co-simulation using the optimal impedances. The fabricated power amplifier with 15
shows the efficiency above 35 %, the power gain of 8.7~8.3 dB and the output power of 46.7~46.3 dBm at 9~9.5 GHz with pulsed-driving width of 10 usec and duty of 10 %.
HF-Band Wireless Power Transfer System with Adaptive Frequency Control Circuit for Efficiency Enhancement in a Short Range
Jang, Byung-Jun ; Won, Do-Hyun ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 22, issue 11, 2011, Pages 1047~1053
DOI : 10.5515/KJKIEES.2011.22.11.1047
In this paper, we proposed an HF-band wireless power transfer system with adaptive frequency control circuit for efficiency enhancement in a short range. In general, a wireless power transfer system shows an impedance mismatching due to a reflected impedance, because a coupling coefficient is varied with respect to separation distance between two resonating loop antennas. The proposed method can compensate this impedance mismatching by varying input frequency of a voltage-controlled oscillator adaptively with respect to separation distance. Therefore, transmission efficiency is enhanced in a short distance, where large impedance mismatch occurs. The adaptive frequency circuit consists of a directional coupler, a detector, and a loop filter. In order to demonstrate the performance of the proposed system, a wireless power transfer system with adaptive frequency control circuits is designed and implemented, which has a pair of loop antennas with a dimension of 30
. From measured results, the proposed system shows enhanced efficiency performance than the case without adaptive frequency control.
Imaging Method in Time Domain for Bistatic Forward-Looking Radar in Short Range Application
Sun, Sun-Gu ; Cho, Byung-Lae ; Lee, Jung-Soo ; Park, Gyu-Churl ; Ha, Jong-Soo ; Han, Seung-Hoon ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 22, issue 11, 2011, Pages 1054~1062
DOI : 10.5515/KJKIEES.2011.22.11.1054
This study describes the time domain imaging algorithm which can be well applied to short-range UWB(ultra wideband) bistatic radar. In the imaging method of SAR technology, the frequency domain method is well applied to the areas which satisfy far-field condition. However in the near-field environment, the image quality is not good due to phase error. However back-projection method based on time domain is well applied to short-range imaging radar. Meanwhile because its processing time is very long, real time-processing is very difficult. To resolve this problem FFBP(Fast Factorized Back-Projection) was proposed. Using the raw data gathered on field we implemented back-projection and FFBP method. Then image quality and processing time were analyzed using these methods.
A Study on Automatic Target Recognition Using SAR Imagery
Park, Jong-Il ; Kim, Kyung-Tae ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 22, issue 11, 2011, Pages 1063~1069
DOI : 10.5515/KJKIEES.2011.22.11.1063
NCTR(Non-Cooperative Target Recognition) and ATR(Automatic Target Recognition) are methodologies to identify military targets using radar, optical, and infrared images. Among them, a strategy to recognize ground targets using synthetic aperature radar(SAR) images is called SAR ATR. In general, SAR ATR consists of three sequential stages: detection, discrimination and classification. In this paper, a modification of the polar mapping classifier(PMC) to identify inverse SAR(ISAR) images has been made in order to apply it to SAR ATR. In addition, a preprocessing scheme can mitigate the effect from the clutter, and information on the shadow is employed to improve the classification accuracy.
A Study on Signal Processing of Rear Radars for Intelligent Automobile
Choi, Gak-Gyu ; Han, Seung-Ku ; Kim, Hyo-Tae ; Kim, Kyung-Tae ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 22, issue 11, 2011, Pages 1070~1077
DOI : 10.5515/KJKIEES.2011.22.11.1070
This paper introduces a radar signal processing technique for intelligent rear view monitoring of an automobile. The linear frequency modulation-frequency shift keying(LFM-FSK) waveform, which is the combination of frequency modulation continuous wave(FMCW) and frequency shift keying(FSK) waveform, is employed to simultaneously estimate the range, relative aspect angle, and velocity of an automobile. Hence, it can be applied to monitor the rear view of an automobile. FMCW waveform has high range resolution capability, but it produces ghost targets under a multiple target environment. In contrast, FSK waveform can provide high velocity resolution and avoids the problem of ghost targets. However, it fails to identify multiple targets along the radar's line of sight. With LFM-FSK waveform, we can estimate the ranges and velocities of multiple targets with very high resolution, which avoids the ghost target problem of an FMCW waveform. Simulation result shows that LFM-FSK wavefrom is suitable for use in the lane change assistance system for an automobile.
UWB Antenna with Triple Band-Notched Characteristics Using the Spiral Resonator and the CSRR
Kim, Jang-Yeol ; Lee, Seung-Woo ; Kim, Nam ; Lee, Sang-Min ; Oh, Byoung-Cheol ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 22, issue 11, 2011, Pages 1078~1091
DOI : 10.5515/KJKIEES.2011.22.11.1078
In this paper, a triple band-notched UWB antennas using a spiral resonator and a complementary split ring resonator is proposed as two types. The band-rejection characteristic of the designed antenna is analyzed through the structure and equivalent circuit model of spiral resonator and CSRR. The measured results of first type antenna show that a VSWR less than 2 was satisfied with a resonant frequency in the range of 1.16~12 GHz and it can be obtained the band-stop performance at 3.3~3.85 GHz, 5.15~6.1 GHz, and 8.025~8.5 GHz. The measured results of second type antenna show that a VSWR less than 2 was satisfied with this antenna works from 1.79 to 12 GHz and it can be achieved the band-notched performance at 3.3~3.88 GHz, 5.12~5.94 GHz, and 8.025~8.51 GHz. Through the measured results, the designed antenna was satisfied UWB band except for triple notched bands.
Ground-Based Rotational SAR System for Field-Experiments
Hwang, Ji-Hwan ; Kwon, Soon-Gu ; Shin, Jong-Chul ; Oh, Yi-Sok ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 22, issue 11, 2011, Pages 1092~1100
DOI : 10.5515/KJKIEES.2011.22.11.1092
A C-band ground-based rotational SAR system is presented in this paper. The rotaional SAR system is a test-bed for future rotational SAR systems which can be deployed in space and on a tower. The test-bed system is designed for imaging the electromagnetic scattering from earth surfaces and buried targets. This paper also presents the examination results of the generated SAR images. This rotational SAR system is basically consisted of the network-analyzer based HPS(Hongik Polarimetric Scatterometer) and a horizontally rotating arm. Several SAR images were obtained using the rotational SAR system for various target areas. To verify this system, we simulated the SAR images for the rotational SAR using the FDTD algorithm and compared between the measured and simulated SAR images. The rotational SAR system is operated at the center frequency of 5 GHz and various frequency bandwidth within 0.5~2 GHz to change the resolution of SAR images.
A Printed, Wideband Folded Monopole Antenna Coupling with a Parasitic Inverted-L Element for Bluetooth, WiMAX and UWB Systems
Kim, Ki-Baek ; Ryu, Hong-Kyun ; Woo, Jong-Myung ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 22, issue 11, 2011, Pages 1101~1110
DOI : 10.5515/KJKIEES.2011.22.11.1101
This paper presents a printed, wideband folded monopole antenna for laptop and tablet computer applications. The proposed antenna is designed to cover bandwidth(2.3~10.6 GHz) of Bluetooth, WiMAX, and UWB system by using the printed folded monopole antenna having asymmetrical line width coupling with a parasitic inverted- L element. Also, wireless LAN band(5.15~5.85 GHz) which interferes with UWB system is rejected by inserting half-wavelength open stub in the folded monopole antenna. -10 dB bandwidth of the fabricated wideband antenna is 2.27~10.6 GHz (4.7:1) and -10 dB band-rejected bandwidth is measured as 700 MHz(5.15~5.85 GHz, 12.72 %). The gain and efficiency of the antenna except for the rejected band are higher than 3.93 dBi and 91.89 % and are measured as -2 dBi and 14.65 % at 5.5 GHz which is band-rejected frequency. The size of the antenna is suitable to install for small space of tablet and laptop computers as 12.75(1
is free space wavelength at 2.3 GHz). Therefore, we verified that the designed antenna is appropriate for wideband antenna of tablet and laptop PC applications.
A 60 GHz Bidirectional Active Phase Shifter with 130 nm CMOS Common Gate Amplifier
Hyun, Ju-Young ; Lee, Kook-Joo ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 22, issue 11, 2011, Pages 1111~1116
DOI : 10.5515/KJKIEES.2011.22.11.1111
In this paper, a 60 GHz bidirectional active phase shifter with 130 nm CMOS is presented by replacing CMOS passive switchs in switched-line type phase shifter with Common Gate Amplifier(bidirectional amplifier). Bidirectional active phase shifter is composed of bidirectional amplifier blocks and passive delay line network blocks. The suitable topology of bidirectional amplifier block is CGA(Common Gate Amplifier) topology and matching circuits of input and output are symmetrical due to design same characteristic of it's forward and reverse way. The direction(forward and reverse way) and amplitude of amplification can be controlled by only one bias voltage(
) using combination bias circuit. And passive delay line network blocks are composed of microstrip line. An 1-bit phase shifter is fabricated by Dongbu HiTek 1P8M 130-nm CMOS technology and simulation results present -3 dB average insertion loss and respectively 90 degree and 180 degree phase shift at 60 GHz.
A Low Phase-Noise Ka-Band Hybrid Frequency Synthesizer for Millimeter Wave Seeker
Lim, Ju-Hyun ; Han, Hae-Jin ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 22, issue 11, 2011, Pages 1117~1124
DOI : 10.5515/KJKIEES.2011.22.11.1117
In this paper, we implemented a Ka-band frequency synthesizer for millimeter wave seeker. We improved frequency synthesizer performance of phase noise, resolution and spurious using the DDS driven hybrid method The proposed frequency synthesizer has the bandwidth of 1 GHz, frequency switching time of below 9
, suppressed spurious level of below -68.9 dBc. phase noise of -113.58 dBc/Hz at offset 100 kHz and flatness of
Improvement of Electromagnetic Environment Effects in aLift System by Installing a Mobile-Communication Repeater
Lim, Byung-Chul ; Jung, Ki-Bum ; Chung, Yeon-Choon ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 22, issue 11, 2011, Pages 1125~1132
DOI : 10.5515/KJKIEES.2011.22.11.1125
The purpose of this study is to suggest installation methods of a mobile-communication repeater into a lift system with consideration of EMC. Two approaches, one(Solution 1) is realized with a repeater installed in a lift hoistway and another(Solution 2) installed inside a lift, were proposed. It is confirmed that the Solution 1 is more effective than the Solution 2. And it is suggested that the EIRP of a repeater must be limited to be
-5 dBm by considering electromagnetic immunity level for a lift and safety margin of 20 dB. This limit can provide suitable electromagnetic environment inside a lift with precise power-control mechanism of mobile communication systems. This study could be a good example of Green ICT by improving electromagnetic environment in spite of radio use.
Omnidirectional Collinear Antenna Using for Multi-Layer PCB Structure
Jung, Huyk ; Suh, Kyoung-Whoan ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 22, issue 11, 2011, Pages 1133~1136
DOI : 10.5515/KJKIEES.2011.22.11.1133
In this paper, we proposed a collinear antenna with a stripline structure for IEEE 802.11b/g applications in ISM (Industrial, Scientific, Medical) band of 2.4~2.5 GHz, which supplements disadvantages of COCO(Coaxial Collinear) antenna and OMA(Omnidirectional planar Microstrip Antenna). By using the proposed 4-layer substrate, we obtained improved performances and advantages in production compared with the existing antenna. In order to get antenna arrays, the same phase structure is designed by alternatively connecting outer conductor to inner conductor with
/2 antenna element, and the substrate of FR4 epoxy (
=0.02) was used for the actual implementation. The maximum gain of about 4.93 dBi was measured, which leaded to a little improved gain of 0.33 dBi in comparison to the existing OMA structure.
Analysis of Transistor's Circuit Coefficients on the Performance of Active Frequency Multipliers
Park, Young-Cheol ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 22, issue 11, 2011, Pages 1137~1140
DOI : 10.5515/KJKIEES.2011.22.11.1137
In this paper, the optimal condition for efficient active frequency multipliers is analyzed. This analysis is based on the effects from transistor nonlinear coefficients, harmonic impedances, and output parasitic components. From the analysis, normalized harmonic power is estimated with the clipping condition of a commercial transistor, and the condition for high conversion efficiency is suggested. From the analysis, a class-F frequency tripler was implemented for the output at 2.475 GHz, showing the maximum efficiency of 22.9 % and the maximum conversion gain of 9.5 dB.
Range Walk Compensated Squint Cross-Range Doppler Processing in Bistatic Radar
Youn, Jae-Hyuk ; Kim, Kwan-Soo ; Yang, Hoon-Gee ; Chung, Yong-Seek ; Lee, Won-Woo ; Bae, Kyung-Bin ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 22, issue 11, 2011, Pages 1141~1144
DOI : 10.5515/KJKIEES.2011.22.11.1141
Range walk has been a major problem in achieving correct Doppler processing. This frequently occurs when range variation is severe just like in a bistatic radar or in high speed target scenario. This paper presents a range walk compensated range-Doppler processing algorithm applicable to the bistatic radar. In order for the compensation, a range-domain interpolation is applied for range compressed signal so that Doppler processing is performed along the evenly time-spaced range bins that contain target returns. Under a bistatic radar scenario, the proposed algorithm including a range domain pulse compression is mathematically described. Finally, the validity of the algorithm is demonstrated by simulation results showing the superiority of a SCDP(Squint Cross-range Doppler Processing) over an uncompensated Doppler processing.