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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 23, Issue 12 - Dec 2012
Volume 23, Issue 11 - Nov 2012
Volume 23, Issue 10 - Oct 2012
Volume 23, Issue 9 - Sep 2012
Volume 23, Issue 8 - Aug 2012
Volume 23, Issue 7 - Jul 2012
Volume 23, Issue 6 - Jun 2012
Volume 23, Issue 5 - May 2012
Volume 23, Issue 4 - Apr 2012
Volume 23, Issue 3 - Mar 2012
Volume 23, Issue 2 - Feb 2012
Volume 23, Issue 1 - Jan 2012
Selecting the target year
Design of the Linked Patch Monopole Antenna and Its SAR Analysis along with Antenna Direction
Yang, Joo-Hun ; Lee, Seungwoo ; Kim, Nam ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 23, issue 10, 2012, Pages 1117~1127
DOI : 10.5515/KJKIEES.2012.23.10.1117
In this paper, the monopole antenna for satisfying GSM900/DCS1800/PCS1900/UMTS2100 services is designed. We can get the characteristic of the low frequency bands by connecting the front patch to the back patch of the antenna and get the low frequency resonance band using a front patch slit. The proposed antenna total volume is
, and it is designed on the FR-4 substrate having a relative dielectric constant of 4.4. As measurement result after fabrication, showed that the resonant frequency bandwidths are 156 MHz(828~984 MHz), 708 MHz(1.476~2.184 GHz) based on the return loss of 10 dB, and the radiation patterns show as the omnidirectional shapes for the E-field and H-field. For analyzing the human effects, the proposed antenna is mounted on the mobile-phone case. The averaged peak SAR over 1 g and 10 g is simulated and measured when the input power is 0.25 W. We have checked the variation of the SAR values when the antenna is mounted 4 different directions, then checked the direction having a relatively higher SAR. The results also satisfied the limiting SAR values which are 1.6 W/kg and 2.0 W/kg averaged over 1 g and 10 g tissues respectively.
A Study on Adjustable Base Station Antenna Based on Electrical Tilt for Null Steering
Lee, Vea-O ; Cheon, Chang-Yul ; Chung, Young Seek ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 23, issue 10, 2012, Pages 1128~1136
DOI : 10.5515/KJKIEES.2012.23.10.1128
In this paper, we propose an electrically tilting system based on a null-steering in order to solve the problem of the shadowing loss caused by the mechanically tilted antenna system in mobile services. Especially, we improve the downward shadowing loss by eliminating or moving the vertical beampattern nulls between
to be able to tilt the downward beampattern between
. The antenna has 14.5 dBi gain and side lobe level (SLL) is lower than -18 dB within downward tilting range. The isolation of polarization is greater than 30 dB when running in electric tilt down to
. To verify this paper, we made the base-station antenna for W-CDMA and beam tilting devices, and verified the performances.
Design of SPA Antenna Using FET Switch for 2.6 GHz
Kang, Hyun-Sang ; Park, Young-Il ; Yong, Hwan-Gu ; Kim, Byung-Sung ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 23, issue 10, 2012, Pages 1137~1144
DOI : 10.5515/KJKIEES.2012.23.10.1137
In this paper, a 2.6 GHz switched parasitic array(SPA) antenna is designed to resolve the device interference in the femtocell. The designed SPA antenna structure consists of a central
monopole antenna as a radiator and surrounding four parasitic elements operating as a reflector or a director depending on the switching state. In addition, open state monopoles around the parasitic elements are placed to improve the directivity. The designed antenna utilizes RF FETs as switching elements instead of conventional PIN diodes, which enables beam steering with a simple structure consuming low power. To select the proper FET switch, the performance of the SPA antenna depending on the switch characteristics is analyzed. The fabricated antenna has 65 mm radius and 35 mm height, which shows about 15 dB front-back-ratio(FBR) at 2.6 GHz and enables eight-directional beam steering.
Broadband 90° Schiffman Phase Shifter Using Slot-Coupled Lines
Rhee, Seung-Yeop ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 23, issue 10, 2012, Pages 1145~1150
DOI : 10.5515/KJKIEES.2012.23.10.1145
In this paper, an improved Schiffman phase shifter is proposed using slot-coupled lines. It consists of the typical coupled lines and a simple rectangular slot which is placed in the ground plane underneath the coupled lines. Phase responses of the slot-coupled Schiffman phase shifter are analyzed in consideration of the phase velocity of two independent transmission modes and the characteristic impedance of slot-coupled line. The
Schiffman phase shifters with high impedance ratio is realized at 2.4 GHz, which cannot be implemented with the conventional coupled lines. The measured results show that the bandwidth is around 74.2 % within the phase errors
. The measured return loss is found to be better than 15.0 dB and insertion loss is less than 1.5 dB over the operating frequency band.
65 nm CMOS Base Band Filter for 77 GHz Automotive Radar Compensating Path Loss Difference
Kim, Young-Sik ; Lee, Seung-Jun ; Eo, Yun-Seong ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 23, issue 10, 2012, Pages 1151~1156
DOI : 10.5515/KJKIEES.2012.23.10.1151
In this paper, the baseband filter is proposed in order to maintain a constant sensitivity regardless of distances for 77 GHz automotive radar system. Using existing DCOC loop circuit can remove DC offset and also cancel differences of received power depending on the distance. Measured results show that the maximum gain is 51 dB and high pass cutoff frequency can be tuned from 5 kHz to 15 kHz. The slope of high pass filter can be tuned from -10 to -40 dB/decade for the distance compensation. The measured NF and IIP3 are 26 dB and +4.5 dBm with 4.3 mA at 1.0 V supply voltage, respectively. The fabricated die size
excluding the in/out pads.
Measurement of Propagation Characteristic of HVAC Ducts within Buildings for Wireless Networks
Yun, Chan-Eui ; Chun, Wan-Jong ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 23, issue 10, 2012, Pages 1157~1165
DOI : 10.5515/KJKIEES.2012.23.10.1157
In this paper, we measure and analyze propagation characteristic of heating, ventilation, and air conditioning(HVAC) ducts within buildings for wireless networks. We analyze the duct structures, implement the feeders exciting propagating modes, and simulate the excitation characteristic. We measure the propagation characteristic of HAVC ducts at 2.45 GHz WiFi band and compare it with that of LOS and partitioned office environments. We propose the design method of wireless network using HVAC ducts based on our results.
Performance Analysis of Direction Finding Systems Using EM Simulation-based Array Manifolds
Kim, Jae-Hwan ; Cho, Chihyun ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 23, issue 10, 2012, Pages 1166~1172
DOI : 10.5515/KJKIEES.2012.23.10.1166
In this paper, by using a commercial EM simulator, we could obtain the array manifold which are phase responses of an array antenna for the incident plane wave and then verified the effectiveness of methodology after comparing with the measurement. The result shows that the array manifold can be calculated including not only the phase response of the ideal point sources but also the influences of the mutual coupling between antennas and the installed platform. Also it can exclude the interference of strong broadcasting signal and the disturbance of the multipath in the calibration process. Finally, to predict the performances of direction finding systems, a novel method using both the EM simulation-based receiving signal and the sparsely sampled array manifold with the parabolic estimation is proposed. This method can be utilized in the various fields of direction-finding since it shows the superior predictive performance even in low SNR conditions.
Collision Avoidance Beamforming for Mitigating Inter-cell Interference in Cooperative Wireless Communication Systems
Mun, Cheol ; Jung, Chang-Kyoo ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 23, issue 10, 2012, Pages 1173~1179
DOI : 10.5515/KJKIEES.2012.23.10.1173
In this paper, collision avoidance beamforming(CA-BF) technology is proposed to mitigate inter-cell interference in cooperative wireless communications system with limited feedback. Each acess terminal(AT) selects both the best BF weight vector for a serving base transceiver station(BTS) and the most interfering BF weight vectors of interfering BTSs within a cluster, and sends it back to a cluster scheduler. At the cluster scheduler, a set of transmit BF weights of BTSs and the corresponding scheduled ATs are jointly determined to avoid collision among beams formed by BTSs within a cluster, which enhances system throughput by mitigating inter-cell interference. It is shown that the proposed CA-BF outperforms existing non-coordinated BF schemes in terms of the average system throughput.
Codebook Design and Centralized Scheduling for Joint Transmission SDMA with Limited Feedback
Mun, Cheol ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 23, issue 10, 2012, Pages 1180~1187
DOI : 10.5515/KJKIEES.2012.23.10.1180
In this paper, joint transmission space division multiple access(JT-SDMA) scheme is proposed to mitigate inter-cell interference(ICI) in cooperative wireless communications system with limited feedback. We propose a systematic design method for a codebook consisting of a finite number of unitary matrices suitable for network multiple-input multiple-output( MIMO) channel characteristics. A centralized cluster scheduling scheme is proposed to both mitigate ICI and maximizes multiuser diversity gain with limited feedback. It is shown that the proposed JT-SDMA scheme outperforms a existing coordinated SDMA scheme even in wireless network environments where sufficient multiuser diversity order can not be provided through efficient ICI mitigation.
A Transmission Technique of Multichannel Receiver Data for the Phased-Array Radar
Jeong, Myung-Deuk ; Kim, Han-Sung ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 23, issue 10, 2012, Pages 1188~1195
DOI : 10.5515/KJKIEES.2012.23.10.1188
The trend for the development of radar is the active phased-array radar system. The trade-off between the processing speed and the number of the signal process board for the real time signal processing has to be optimized particularly in multichannel radar system. This paper introduces a transmission technique in order to transmit a large amount of received data from an Antenna Part to Signal Process Part. As a result, the number of the S/L board(COTS board) is reduced to one half, and the margin of the data transmission rate is about 2 times higher than the original method.
Verification of a Calibration Technique for a Full-Polarimetric Scatterometer System at C-band
Park, Sin-Myeong ; Go, Joo-Seoc ; Joo, Jeong-Myeong ; Kim, Hee-Young ; Kim, Ju-Hui ; Hwang, Ji-Hwan ; Kwon, Soon-Gu ; Shin, Jong-Chul ; Oh, Yisok ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 23, issue 10, 2012, Pages 1196~1203
DOI : 10.5515/KJKIEES.2012.23.10.1196
This paper presents a study on the calibration of a C-band HPS(Hongik Polarimetric Scatterometer) system using the DMMCT(Differential Mueller Matrix Calibration Technique). For calibration of the polarimetric scatterometer system, a fully-polarimetric antenna pattern(magnitudes and phase-differences) of the antenna main-beam is measured using a conducting sphere at anechoic chamber. The polarimetric scatterometer system could be accurately calibrated after retrieving its distortions using the DMMCT. Unlike a single-polarimetric system, in a fully-polarimetric system, not only backscattering coefficients but also phase differences are important parameters. This calibrated HPS system can be used to measure accurate Mueller matrices of bare soil surfaces, rice paddies, and vegetation fields. The phase-difference parameters as well as the backscattering coefficients for co- and cross-polarizations can then be obtained. The accuracy of calibration was verified by comparing the measured backscattering coefficients with a scattering model. The measured polarization response of a plowed bare field was also compared with the polarization response which was synthesized using a polarimetric scattering model for verifying the calibration technique.
Analysis of the Radiation Patterns of Satellite SAR System with Active-Transponder
Hwang, Ji-Hwan ; Kweon, Soon-Koo ; Oh, Yisok ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 23, issue 10, 2012, Pages 1204~1211
DOI : 10.5515/KJKIEES.2012.23.10.1204
Measurement and analysis results of the extracted radiation-patterns from the field-experiments which were conducted to acquire the generic technology for calibration and validation of the satellite SAR system(Synthetic Aperture Radar) are presented in this study. Prototype of active transponder is adjustable within maximum 63.1 dBsm of RCS (Radar Cross Section) and includes the receiving-function with external receiver. To increase an accuracy of these field experiments, we repetitively measured satellite SAR systems of the same operating mode(i.e., COSMO-SkyMed No. 2 & 3, hh-pol., strip-map himage mode, 3 m resolution). Then, the reliability of experimental results was cross-checked through analysis of the RCS of active transponder on SAR image. The property of azimuth radiation patterns of satellite SAR system extracted from them has
of HPBW(half-power beamwidth),
of FNBW(first-null beamwidth), and 11.17 dB of PSLR(peak to side lobe ratio), respectively.
Accuracy Improvement of the Estimated Angle Using Phase Averaging in Phase-Comparison Monopulse Algorithm
Cho, Byung-Lae ; Lee, Jung-Soo ; Lee, Jong-Min ; Sun, Sun-Gu ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 23, issue 10, 2012, Pages 1212~1215
DOI : 10.5515/KJKIEES.2012.23.10.1212
This study describes the accuracy improvement of the estimated angle using phase averaging in phase-comparison monopulse algorithm. In addition, to compensate the time-delay due to the phase averaging, we propose the time-delay compensation algorithm which uses the derivative of the estimated angle. These derivative is calculated by the curve fitting method. Using the real radar interferometer, we have verified that the phase averaging and time-delay compensation algorithms are effective in real-time signal processing application.