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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
Editor in Chief :
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
A Small Antenna of High Radiation Efficiency Employing a Ground Radiator
Choi, Hyeng-Cheul ; Lee, Hyung-Jin ; Park, Bum-Ki ; Jang, Jin-Hyuk ; Kim, Hyeong-Dong ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 23, issue 2, 2012, Pages 135~143
DOI : 10.5515/KJKIEES.2012.23.2.135
This paper introduces the method to utilize a terminal ground as a radiator only using reactive components without an antenna structure. Characteristics of the proposed antenna is compared with that of the meander IFA on the same ground plane(
) for the bluetooth band. From simulation and measurement data, it is found that the proposed antenna using only capacitors provides the highest radiation efficiency. This is because of that the higher inductance reduces radiation resistance of a ground and the capacitor has a lower loss resistance comparing to that of the IFA or the inductor. In spite of the high radiation efficiency, the area (
) of the proposed antenna is less than half of the area (
) of the IFA.
Design of Circularly Polarization Patch Array Antenna for DSRC
Kim, Hyun-Chul ; Jung, Jin-Woo ; Lee, Hyeon-Jin ; Lim, Yeong-Seog ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 23, issue 2, 2012, Pages 144~150
DOI : 10.5515/KJKIEES.2012.23.2.144
In this paper, circularly polarization patch array antenna of RSE(Road-side Equipment) base station for DSRC(Dedicated Short Range Communication) of ITS(Intelligent Transport System) is proposed. The antenna of RSE base station for DSRC is designed to operate circularly polarization to receive reflected signal from multiplex path effectively. The proposed antenna consisted of microstrip patch and feed line, the slit is inserted in the proximity of the slot of feed structure to generate circularly polarization. The
array structure is designed to satisfying gain that DSRC RSE base station antenna required. Measured impedance bandwidth and axial-ratio bandwidth are satisfied by all DSRC band of 5.795~5.855 GHz. Vertical and horizontal HPBW of the proposed antenna are both about 43 degrees, it showed gain characteristic of about 11.21 dBi.
H-Plane 8-Way Rectangular Waveguide Power Divider Using Y-Junction
Lee, Sang-Heun ; Yoon, Ji-Hwan ; Yoon, Young-Joong ; Kim, Jun-Yeon ; Lee, Woo-Sang ; Park, Seul-Gi ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 23, issue 2, 2012, Pages 151~158
DOI : 10.5515/KJKIEES.2012.23.2.151
This paper proposes a H-plane 8-way rectangular waveguide power divider using Y-junction. A general N-way power divider can be composed of multi-stage T-junctions. However, if the distances of output ports are close, the matching characteristic is not improved by using only T-junctions because of space limitation. In this case, since other types of 3-port junctions should be used to final output stage, Y-junctions are used with T-junctions in this paper. The proposed Y-junction uses the tapered-line impedance transformer and inductive irises to improve impedance matching characteristic. The 8-way power divider using Y-junction is fabricated and measured. The measured return loss and insertion loss from input port to output port are -30.8 dB and -9.3 dB at operating frequency, respectively. The measured maximum phase difference is about
. Therefore, the proposed power divider will be useful to apply to various microwave systems, which need to divide the input power equally, such as feed networks for array antennas.
Performance Evaluation of Antipodal Vivaldi Antenna in the Time- and Frequency-Domains for IR-UWB Systems Application
Koh, Young-Mok ; Kim, Keun-Yong ; Ra, Keuk-Hwan ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 23, issue 2, 2012, Pages 159~168
DOI : 10.5515/KJKIEES.2012.23.2.159
In this paper, we designed the antipodal vivaldi antenna for IR-UWB systems application and evaluated IR-UWB antenna performance for the ultra wideband impulse signal transmission in the time- and frequency-domain. The designed antipodal vivaldi antenna was fabricated using FR-4 substrate which thickness 1.6 mm, dielectric constant
. We measured the return loss, far filed radiation pattern at the anechoic chamber in the frequency-domain. We also performed the pulse fidelity analysis in the time-domain using nano-second impulse signal transmission and demonstrated the feasibility of ultra wideband signal stable transmission in the UWB band. The designed and fabricated antipodal vivaldi antenna could be emitting and receiving the IR-UWB signal while preserving low pulse distortion and good radiation pattern in time- and frequency-domain.
A Study for Improving Computational Efficiency in Method of Moments with Loop-Star Basis Functions and Preconditioner
Yeom, Jae-Hyun ; Park, Hyeon-Gyu ; Lee, Hyun-Suck ; Chin, Hui-Cheol ; Kim, Hyo-Tae ; Kim, Kyung-Tae ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 23, issue 2, 2012, Pages 169~176
DOI : 10.5515/KJKIEES.2012.23.2.169
This paper uses loop-star basis functions to overcome the low frequency breakdown problem in method of moments (MoM) based on electric field integral equation(EFIE). In addition, p-Type Multiplicative Schwarz preconditioner (p-MUS) technique is employed to reduce the number of iterations required for the conjugate gradient method(CGM). Low frequency instability with Rao Wilton Glisson(RWG) basis functions in EFIE can be resolved using loop-start basis functions and frequency normalized techniques. However, loop-star basis functions, consisting of irrotational and solenoidal components of RWG basis functions, require a large number of iterations to calculate a solution through iterative methods, such as conjugate gradient method(CGM), due to high condition number. To circumvent this problem, in this paper, the pMUS preconditioner technique is proposed to reduce the number of iterations in CGM. Simulation results show that pMUS preconditioner is much faster than block diagonal preconditioner(BDP) when the sparsity of pMUS is the same as that of BDP.
Design and Crosstalk Analysis of MEMS Probe Connector System
Bae, Hyeon-Ju ; Kim, Jong-Hyeon ; Lee, June-Sang ; Pu, Bo ; Lee, Jae-Joong ; Nah, Wan-Soo ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 23, issue 2, 2012, Pages 177~186
DOI : 10.5515/KJKIEES.2012.23.2.177
In this paper, we propose a design method that the crosstalk of probe connector pins satisfy the limitation of -30 dB. The parameters(inductance and capacitance) were extracted in the grid-structured probe connector pin system, and it is shown that the new parameters are easily calculated with increasing ground pin numbers using the previously calculated parameters. In addition, the crosstalk reduction algorithm by employing more grounds around the signal pin has been suggested, and it is confirmed that the suggested method is quite effective especially for the reduction of inductive couplings. Finally, we suggested the correlation between the pitch and the length of the pins to satisfy the crosstalk limitation of -30 dB with the given number of ground pins, which will be quite useful when design a probe connector pin system.
Optimization of Subarray Configurations in Linear Array Antenna Using Modified Genetic Algorithm
Kim, Jun-Ho ; Kim, Doo-Soo ; Kim, Seon-Ju ; Yang, Hoon-Gee ; Cheon, Chang-Yul ; Chung, Young-Seek ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 23, issue 2, 2012, Pages 187~195
DOI : 10.5515/KJKIEES.2012.23.2.187
In this paper, we propose the optimization of subarray configurations for linear array to minimize the side lobe level (SLL) in sum beam pattern based on the genetic algorithm. The operations of genetic algorithm are modified to be applied to subarray configurations. Using the proposed method, we construct subarray structure with 16 irregular subarray elements from 40 linear array elements to minimize the SLL in sum beam pattern in case of applying the adaptive beamforming(ABF) to suppress the jamming power, whose the SLL is 10 dB lower than that of regular subarray configuration.
Stochastic Radar Beam Scheduling Using Simulated Annealing
Roh, Ji-Eun ; Ahn, Chang-Soo ; Kim, Seon-Joo ; Jang, Dae-Sung ; Choi, Han-Lim ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 23, issue 2, 2012, Pages 196~206
DOI : 10.5515/KJKIEES.2012.23.2.196
AESA radar is able to instantaneously and adaptively position and control the beam, and such adaptive beam pointing of AESA radar enables to remarkably improve the multi-mission capability, compared with mechanically scanned array radar. AESA radar brings a new challenges, radar resource management(RRM), which is a technique efficiently allocating finite resources, such as energy and time to each task in an optimal and intelligent way. Especially radar beam scheduling is the most critical component for the success of RRM. In this paper, we proposed stochastic radar beam scheduling algorithm using simulated annealing(SA), and evaluated the performance on the multi-function radar scenario. As a result, we showed that our proposed algorithm is superior to previous dispatching rule based scheduling algorithm from the viewpoint of beam processing latency and the number of scheduled beams, with real time capability.
A 70/140 GHz Dual-Band Push-Push VCO Based on 0.18-㎛ SiGe BiCMOS Technology
Kim, Kyung-Min ; Kim, Nam-Hyung ; Rieh, Jae-Sung ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 23, issue 2, 2012, Pages 207~212
DOI : 10.5515/KJKIEES.2012.23.2.207
In this work, a 70/140 GHz dual-band push-push voltage controlled oscillator(VCO) has been developed based on a 0.18-
SiGe BiCMOS technology. The lower band and the upper band oscillation frequency varied from 67.9 GHz to 76.9 GHz and from 134.3 GHz to 154.5 GHz, respectively, with tuning voltage swept from 0.2 to 2 V. The calibrated maximum output power for each band was -0.55 dBm and -15.45 dBm. The VCO draws DC current of 18 mA from 4 V supply.
Fabrication of Multiple-Frequency Exposure System for In Vitro Experiment
Kim, Tae-Hong ; Seo, Min-Gyeong ; Mun, Ji-Yeon ; Pack, Jeong-Ki ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 23, issue 2, 2012, Pages 213~219
DOI : 10.5515/KJKIEES.2012.23.2.213
Recently, we are simultaneously exposed by various electromagnetic sources due to an increase of mobile communication services. However, EMF(Electric, Magnetic and Electromagnetic Field) study has been performed mainly about only single frequency. The objective of this paper is to develop an multiple-frequency exposure system for in vitro experiment. The exposure unit for in vitro experiments was designed by radial transmission line type to get broadband characteristics to generate signals of CDMA at 836.5 MHz and WCDMA at 1950 MHz frequency simultaneously. The modulated signals were delivered to the conical antenna through amplifier, digital attenuator and RF combiner. SAR values were obtained by the averaged values of 3 measured values at 9 points in petri dish using the fiber optic temperature probe. The measured return loss was under -15 dB. For 1 W input power, the mean value and standard deviation of SAR were
for the CDMA frequency and
for the WCDMA frequency.
Design and Fabrication of Ka-Band Active PIN Diode Limiter for a Millimeter Wave Seeker
Yang, Seong-Sik ; Lim, Ju-Hyun ; Na, Young-Jin ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 23, issue 2, 2012, Pages 220~228
DOI : 10.5515/KJKIEES.2012.23.2.220
In this paper, we explained the design technique about Ka-band active limiter for protecting the receiver of a millimeter wave seeker. To implement low flat leakage power, we proposed the control circuit of active limiter to control limiter voltage with PRF(Pulse Repetition Frequency) signal and input power. This active limiter consisted of the conventional 2 stage passive limiter, a feedback circuit with a directional coupler, detector, non-inverting amplifier and over-current protection resistance. As the test result of the fabricated Ka-band limiter, it had 1 GHz bandwidth, 3.5 dB insertion loss at the small input power and -7.5 dBm flat leakage at the 4 W RF input power, respectively.
Effect of Body Movement and Position of Antenna on the Capacity of WBAN Channel
Ahn, Chun-Soo ; Ahn, Byoung-Jik ; Kim, Sun-Woo ; Choi, Jae-Hoon ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 23, issue 2, 2012, Pages 229~234
DOI : 10.5515/KJKIEES.2012.23.2.229
This paper presents channel measurements for wireless body area network(WBAN) and provides performance evaluation from the measurement. We measured the radio propagation in 2.45 GHz ISM band in an anechoic chamber according to various human movements and the position of transmit antennas. Two transmit antennas are mounted on different positions of human body for the purpose of comparing the diversity gain and correlation between the channels in
multiple-input single-output(MISO) systems. The experimental results show that the outage capacity is closely related with the correlation coefficient between channels in transmit diversity system.
Performance Improvement of PSAM Channel Estimation Method for OFDM Systems over Frequency-Selective Channel
Kim, Young-Soo ; Bae, Jeong-Gook ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 23, issue 2, 2012, Pages 235~243
DOI : 10.5515/KJKIEES.2012.23.2.235
In this paper, we propose a method to improve performance of pilot symbol assisted modulation(PSAM) channel estimation method for OFDM systems over frequency selective channel. When channel values are estimated, the low pilot density used for channel estimation increases not only the effective data rate but also power efficiency. Thus, the lower pilot density which is used for channel estimation is better for OFDM system. At first, we estimate the channel values which are located at the middle of adjacent pilots, and then all of the possible channel values are estiamted by using original pilot values and previously estimated pilot values. Furthermore, the error of estimated channel values is reduced by introducing guard interval which is designed acccording to maximum channel delay. Performance achieved with the proposed method is illustrated by simulation experiments in comparison with the existing methods in terms of mean squared error(MSE).
Applicator of Hyperthermia with Compact Dipole Antenna Array
Kim, Ki-Joon ; Choi, Woo-Cheol ; Choi, Jae-Hoon ; Yoon, Young-Joong ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 23, issue 2, 2012, Pages 244~250
DOI : 10.5515/KJKIEES.2012.23.2.244
The compact dipole antenna elements and array structure is proposed. The array structure is designed for applicator in regional hyperthermia treatment to enhance the uniformity of the heat distribution which makes the treatment effective and prevents overheating. The compact dipole is designed with branched dipole and matching network to have small size and symmetric shape. The temperature simulation with specific absorption rate(SAR) and bio-heat equation is performed to have heat distribution. The applicator is designed, fabricated, and measured with multi-channel thermometer in 30 and 60 minutes. The simulation and measurement results showed agreement and the simulation in body circumstance has proper temperature result for hyperthermia therapy.
Calculation of the Electromagnetic Fields Distribution around the Human Body and Study of Transmission Loss Related with the Human Body Communication
Ju, Young-Jun ; Gimm, Youn-Myoung ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 23, issue 2, 2012, Pages 251~257
DOI : 10.5515/KJKIEES.2012.23.2.251
Human body communication means transmitting and receiving data through human body medium or through free space along with the human body skin. Electric field distribution around the human body between the transmitter and the receiver were calculated at five different frequencies with 5 MHz interval between 10 MHz and 30 MHz. Commercial electromagnetic simulation tool was used for the calculation of E-field distributions applying the Korean standard male model including 29 different kinds of human tissues. After calculating specific absorption rate(SAR) values on back of the hand, it was compared with International Commission on Non-Ionizing Radiation Protection(ICNIRP) human protection guideline. While conductivities(
) and relative permittivities(
) of the human tissues for each frequency were input as the analyzing parameters, electric field intensities near both hands were integrated along the integral line between the nearby electrodes for the calculation of the transmitting and receiving voltages whose ratio was defined as channel loss. The calculated channel losses were about (
) dB and showed nearly flat response all through the evaluated frequencies.
Altitude Error Analysis of Helicopter-Borne FMCW Radar Altimeter
Jung, Jung-Soo ; Lee, Ho-Jun ; Kwag, Young-Kil ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 23, issue 2, 2012, Pages 258~261
DOI : 10.5515/KJKIEES.2012.23.2.258
Helicopter-borne FMCW radar altimeter obtains the altitude information using the beat frequency between the transmitted and reflected signal from the nadir direction. However, the altitude error may exist when the strong echoes are received from the large RCS at the off-nadir direction because of the wide beamwidth of the altimeter antenna. In this paper, in order to investigate the effect of the altitude error due to the large RCS around the off-nadir direction, the reflected signals were measured by using the corner reflectors displaced on the several reference ground positions, and the acquired signals were analyzed and compared in the spectral domain. The analysis results can be used for the improvement of the altitude accuracy in the radar altimeter.
A Ka-Band 8 W Power Amplifier Module Using 4-Way Waveguide Power Combiners with High Isolation
Shin, Im-Hyu ; Kim, Choul-Young ; Lee, Man-Hee ; Joo, Ji-Han ; Lee, Sang-Joo ; Kim, Dong-Wook ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 23, issue 2, 2012, Pages 262~265
DOI : 10.5515/KJKIEES.2012.23.2.262
In this paper, a Ka-band 8 W power amplifier module with WR-28 waveguide input and output ports is implemented and measured using four 2 W power amplifier modules and 4:1 waveguide power combiners with high isolation of 25 dB at 35 GHz. The 2 W power amplifier modules are fabricated using waveguide-to-microstrip transitions and show output power of 32.5~33.3 dBm and power gain of 26.9~28.7 dB at 35 GHz. Four 2 W power amplifier modules are combined through 4:1 waveguide power combiners with resistive septum and the combined power shows 39.0 dBm(8 W) under 6 V drain bias and 39.6 dBm(9.1 W) under 6.5 V drain bias at 35 GHz.
A Study on Signal Processing of Ballistic Missile Warhead Discrimination Using ESPRIT in Millimeter-Wave(Ka-Band) Seeker
Choi, Gak-Gyu ; Han, Seung-Ku ; Jo, Hee-Jin ; Kim, Hyo-Tae ; Kim, Kyung-Tae ; Song, Sung-Chan ; Na, Young-Jin ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 23, issue 2, 2012, Pages 266~269
DOI : 10.5515/KJKIEES.2012.23.2.266
This paper introduces a signal processing technique for discrimination of ballistic missile's warhead. An interceptor missile to destroy the enemy's ballistic missile requires an information on the location of missile's warhead. In order to detect and locate the missile's warhead, a seeker radar in the interceptor missile makes use of chirp waveform to generate high resolution range profiles(HRRPs). We applied one of the well known spectral estimation technique called ESPRIT (Estimation of Signal Parameters by Rotational Invariance Technique) to these HRRPs to estimate scattering centers on the target. Using the information on the one-dimensional(1-D) scattering centers, we can find the location of the warhead by estimating the length of the missile, Simulation results show that the proposed signal processing technique is efficient in discriminating the warhead of an ballistic missile.
Bolt Shape UHF RFID Tag Antenna for Insertion to a Tree
Chung, You-Chung ; Jeon, Byung-Don ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 23, issue 2, 2012, Pages 270~273
DOI : 10.5515/KJKIEES.2012.23.2.270
A plastic bolt shape UHF RFID tag has been developed for a live tree. The UHF tag is designed and installed into the head part of the bolt, inserted into a tree for management of tree. If the tag antenna is installed near the high dielectric constant material, the impedance of the tag antenna will be changed, and the tag does not work. Therefore, the dielectric constants of wood and plastic bolt are considered for tag antenna design. The input reflection coefficient characteristics and the reading range patterns are measured and compared. This UHF RFID tag can be applied into a live tree, and the status and location of tree can be controlled with the RFID tag. This developed UHF tag can be applied to any applications and objects using a bolt.