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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
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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
Beam Scheduling Algorithm of Multi-Function AESA Radar Based on Dispatching Rules
Roh, Ji-Eun ; Ahn, Chang-Soo ; Kim, Seon-Joo ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 23, issue 1, 2012, Pages 1~13
DOI : 10.5515/KJKIEES.2012.23.1.001
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 the several dispatching rules for radar beam scheduling, and compared the performance on the multi-function radar scenario. We also showed that the dispatching rule which differently applying SPF(Shortest Processing time First) and ERF(Earliest Request time First) according to beam processing latency is the most efficient.
Performance Advantage of Partial CoMP Transmission Using Finite Feedback
Park, Jae-Yong ; Sung, Won-Jin ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 23, issue 1, 2012, Pages 14~20
DOI : 10.5515/KJKIEES.2012.23.1.014
CoMP(Coordinated Multi-Point transmission and reception) refers to a cooperative transmission strategy to control the interference from adjacent base stations in cellular mobile communication systems, which efficiently enhances the data throughput of the systems. As the number of the base stations participating in cooperative transmission increases, however, a larger amount of information exchange to carry the CSI(Channel State Information) of the mobile terminals is required. In this paper, we propose a partial CoMP transmission method for systems under the constraint of finite feedback information data. This method selects candidates of base stations which can provide high efficiency gain when they participate in the CoMP set. To achieve this, the cooperative base station combination is constructed by considering the preferred base stations of users. The cooperative base station combinations are dynamically applied since the preferred base station combinations of users may be different. We perform computer simulations to compare performance of the non-CoMP, full-CoMP and partial CoMP in terms of the average throughput using finite feedback and demonstrate the performance improvement of the proposed method.
Flexible Zeroth-Order Resonant(ZOR) Antenna Independent of Curvature Diameter
Lim, In-Seop ; Chung, Tony J. ; Lim, Sung-Joon ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 23, issue 1, 2012, Pages 21~28
DOI : 10.5515/KJKIEES.2012.23.1.021
In this paper, we propose a flexible zeroth-order resonant(ZOR) antenna. Its zero phase constant ensures that the antenna performance is independent of substrate deformation. A composite right/left-handed transmission line is designed based on coplanar waveguide technology to realize the zeroth-order resonance phenomenon. The CRLH is an implementation of metamaterial(left handed material) which is composed of shunt inductance and series capacitance. In order to yield additional circuital parameter, chip inductor and gap capacitor is added, respectively. The proposed ZOR antenna provides good performances: reasonable bandwidth(6.5 %) and peak gain(0.69~1.39 dBi). Simulated and measured results show that the antenna's resonant frequencies and radiation patterns are almost unchanged at different curvature diameters of 30, 50, 70 mm, as well as for a flat surface.
A Study on the Stabilized System Operation Considering the Reflection Characteristic of an Active-Phased Array Antenna
Kim, Young-Wan ; Chae, Hee-Duck ; Lee, Dong-Kook ; Jeong, Myung-Deok ; Park, Jong-Kuk ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 23, issue 1, 2012, Pages 29~37
DOI : 10.5515/KJKIEES.2012.23.1.029
In this paper, a stabilizd system operation through a composition of a protective circuit and an improvement of active reflection coefficient(ARC) is studied. Unlike the passive-phased array antenna, the APPA is a combined form of radiating element and transmitter-reciever module. Therefore, a definition of new ARC that differentiates itself from typical passive-phased array antenna must apply. The ARC is a reflection coefficient considering a superposition of a coupling from nearby radiating elements and self reflection. It is an important parameter that predicts and analyzes charateristics of a APPR system. A high level ARC is a direct source inducing a performance degradation of a system. In this paper, as a method for a stabilized operation of APAR, one method for improving a performance and another for degradation prevention are analyzed. An effectiveness of two methods was validated using experiment results of real-fabricated active-phased array antenna.
Decision Feedback Equalizer Based on LDPC Code for Fast Processing and Performance Improvement
Kim, Do-Hoon ; Choi, Jin-Kyu ; Ryu, Heung-Gyoon ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 23, issue 1, 2012, Pages 38~46
DOI : 10.5515/KJKIEES.2012.23.1.038
In this paper, we propose a decision feedback equalizer based on LDPC(Low Density Parity Check) code for the fast processing and performance improvement in OFDM system. LDPC code has good error correcting capability and its performance approaches the Shannon capacity limit. However, it has longer parity check matrix and needs more iteration numbers. In our proposed system, MSE(Mean Square Error) of signal between decision device and decoder is fed back to equalizer. This proposed system can improve BER performance because it corrects estimated channel response more accurately. In addition, the proposed system can reduce complexity because it has a lower number of iterations than system without feedback at the same performance. Simulation results evaluate and show the performance of OFDM system with the CFO and phase noise in multipath channel.
The Development of HILS and Test Equipment for Millimeter-Wave (Ka-Band) Seeker's Test and Evaluation
Song, Sung-Chan ; Na, Young-Jin ; Yoon, Tae-Hwan ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 23, issue 1, 2012, Pages 47~55
DOI : 10.5515/KJKIEES.2012.23.1.047
This paper describes the developed HILS and test equipment in order to test the performances of MMW(Millimeter-Wave) seeker which can detect and track a high speed of short-range ballistic missile and aircraft. This system is used to 141 horn antenna array, array switching, and gain and phase control algorithm to simulate various kind of targets and trajectory of high speed and maneuver moving target. In addition, it simulates not only velocity and range for these targets but also clutter and jamming environments. System configuration and implementation and the measurement results of major subsystems such as target motion simulator, simulation signal generator, high speed data aquisition unit, and central control unit are presented. These systems could verify the detection and tracking performance of MMW seeker through dynamic real-time test based on simulation flight scenario.
Sweep Nonlinearity Estimation for High Range Resolution Millimeter-Wave Seeker Using Least Squares Method
Yang, Hee-Seong ; Chun, Joo-Hwan ; Song, Sung-Chan ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 23, issue 1, 2012, Pages 56~67
DOI : 10.5515/KJKIEES.2012.23.1.056
In this thesis, to compensate the sweep nonlinearity occurring in the high resolution radar system using FMICW or FMCW, the method of the estimation of the nonlinearity is proposed. The nonlinear phase component caused by the nonlinear characteristic of the radar system is modelled as a linear combination of the sinusoidal functions consisting of various magnitudes and phases(systematic nonlinear phase error) and a random component(stochastic nonlinear phase error). From two IF signals that are measured respectively independently for two reference point targets lying in different distances which are known, a sparse linear equation is made and solved by least squares method to estimate the nonlinear phase component. The estimated component can be used for predistortion method to compensate the sweep nonlinearity.
Load Insensitivity Analysis of Balanced Power Amplifier for W-CDMA Handset Applications
Kim, Un-Ha ; Kang, Sung-Yoon ; Cheon, Clifford D.Y. ; Kwon, Young-Woo ; Kim, Jung-Hyun ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 23, issue 1, 2012, Pages 68~75
DOI : 10.5515/KJKIEES.2012.23.1.068
The load-insensitivity of the balanced power amplifier(PA) for W-CDMA handset applications is analyzed. The load impedances of the two parallel amplifiers in the balanced PA depending on the output load mismatch are mathematically calculated and with the result, the phase of reflection coefficient at which the linear output power is severely degraded is investigated. From the analysis, we proposed that the linearity of the balanced PA at the phase can be improved by properly increasing the transistor size and thus, multiple balanced PA's with different transistor size are designed and simulated. The simulation result showed that the balanced PA with larger transistor size has improved linear output power under VSWR=4:1.
Design and Fabrication of Ka-Band Microstrip to Waveguide Transitions Using E-Plane Probes
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 1, 2012, Pages 76~84
DOI : 10.5515/KJKIEES.2012.23.1.076
In this paper, two kinds of E-plane microstrip-to-waveguide transitions are optimally designed and fabricated for combining output power from multiple small-power amplifiers in a WR-28 waveguide because conventional K connectors cause unnecessary insertion loss and adaptor loss. The transition design is based on target specifications such as a center frequency of 35 GHz, bandwidth of
, 0.1 dB insertion loss and 20 dB return loss. Performance variation caused by mechanical tolerance and assembly deviation is fully evaluated by three dimensional electromagnetic simulation. The fabricated back-to-back transitions with 16 mm and 26.57 mm interstage microstrip lines show insertion loss per transition of ~0.1 dB at 35 GHz and average 0.2 dB over full Ka band. Also the back-to-back transition shows return loss greater than 15 dB, which implies that the transition itself has return loss better than 20 dB.
Spectral Analysis Method to Eliminate Spurious in FMICW HRR Millimeter-Wave Seeker
Yang, Hee-Seong ; Chun, Joo-Hwan ; Song, Sung-Chan ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 23, issue 1, 2012, Pages 85~95
DOI : 10.5515/KJKIEES.2012.23.1.085
In this thesis, we develop a spectral analysis scheme to eliminate the spurious peaks generated in HRR Millimeterwave Seeker based on FMICW system. In contrast to FMCW system, FMICW system generates spurious peaks in the spectrum of its IF signal, caused by the periodic discontinuity of the signal. These peaks make the accuracy of the system depend on the previously estimated range if a band pass filter is utilized to eliminate them and noise floor go to high level if random interrupted sequence is utilized and in case of using staggering process, we must transmit several waveforms to obtain overlapped information. Using the spectral analysis one of the schemes such as IAA(Iterative Adaptive Approach) and SPICE(SemiParametric Iterative Covariance-based Estimation method) which were introduced recently, the spurious peaks can be eliminated effectively. In order to utilize IAA and SPICE, since we must distinguish between reliable data and unreliable data and only use reliable data, STFT(Short Time Fourier Transform) is applied to the distinguishment process.
Homogenizaion over Whole Field of View in High Field MRI
Kim, Hong-Joon ; Son, Hyeok-Woo ; Cho, Young-Ki ; Yoo, Hyoung-Suk ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 23, issue 1, 2012, Pages 96~100
DOI : 10.5515/KJKIEES.2012.23.1.096
In high static field magnetic resonance imaging(MRI) systems,
fields of 7 T and 9.4 T, the impressed RF field shows larger inhomogeneity than in clinical MRI systems with B0 fields of 1.5 T and 3.0 T. In multi-channel RF coils, the magnitude and phase of the input to each coil element can be controlled independently to reduce the non-uniformity of the impressed RF
field. The convex optimization technique has been used to obtain the optimum excitation parameters with iterative solutions for homogeneity in a selected ROI(Region of Interest). To demonstrate the technique, the multichannel transmission line coil was modeled together with a human head phantom at 400 MHz for the 9.4 T MRI system and
fields are obtained. In this paper, all the optimized
in each isolated ROIs are combined to achieve significantly improved homogeneity over the entire field of view. The simulation results for 9.4 T MRI systems are discussed in detail.
The Study on Implementation of a Semi-Solid Flat Phantom with Equivalent Electrical Properties to Whole Human Body at MICS and ISM Band
Lee, Soon-Yong ; Seo, Won-Bum ; Kwon, Kyeol ; Choi, Jea-Hoon ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 23, issue 1, 2012, Pages 101~107
DOI : 10.5515/KJKIEES.2012.23.1.101
When wireless devises for MICS(Medical Implant Communication Service) or ISM(Industrial Scientific and Medical) bands are designed, it is necessary to verify the performance by using a human body flat phantom. However, most of studies on the phantom are limited to the biological effects of mobile-phone EMF. In this paper, semi-solid phantoms having the electric properties suggested by FCC at MICS and ISM bands are fabricated. The manufactured phantoms satisfy the electric properties(
at MICS band,
at ISM band) at each band. All the composing materials for phantoms are commercially available in domestic market. Two methods using both polyethylene powder and TX-151 and glycerin at each band are proposed for diverse purpose. The electrical properties of the fabricated phantoms are measured by a dielectric probe kit and network analyzer after the lapse of one day (24 hours).
Dispersive FDTD Modeling of Human Body with High Accuracy and Efficiency
Ha, Sang-Gyu ; Cho, Jea-Hoon ; Kim, Hyeong-Dong ; Choi, Jae-Hoon ; Jung, Kyung-Young ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 23, issue 1, 2012, Pages 108~114
DOI : 10.5515/KJKIEES.2012.23.1.108
We propose a dispersive finite-difference time domain(FDTD) algorithm suitable for the electromagnetic analysis of the human body. In this work, the dispersion relation of the human body is modeled by a quadratic complex rational function(QCRF), which leads to an accurate and efficient FDTD algorithm. Coefficients(involved in QCRF) for various human tissues are extracted by applying a weighted least square method(WLSM), referred to as the complex-curve fitting technique. We also presents the FDTD formulation for the QCRF-based dispersive model in detail. The QCRFbased dispersive model is significantly accurate and its FDTD implementation is more efficient than the counterpart of the Cole-Cole model. Numerical examples are used to show the validity of the proposed FDTD algorithm.
Longitudinal Shunt Slot Array Antenna in the Broad Wall of Waveguide for Millimeter-Wave(Ka-Band) Seeker
Park, Jung-Yong ; Lee, Jae-Ho ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 23, issue 1, 2012, Pages 115~121
DOI : 10.5515/KJKIEES.2012.23.1.115
In this paper, the design and fabrication of slot array in the broad wall of the waveguide for Ka-band monopulse radar are discussed. The aperture distributions are designed for the desired antenna gain, beamwidth and Side-lobe Level(SLL), and then slot parameters, such as lengths and offsets, are obtained for corresponding to each slot admittance in the equivalent circuit by using Elliot's array synthesis procedure. MWS-CST simulation shows the return loss below -10 dB, antenna gain above 32 dBi, 3 dB beamwidth of 3.7 degree and SLL of -20 dB. In order to demonstrate the expected results, the designed antenna is fabricated and measured.
Design of a Broadband Window Antenna Using a Parallel T-Matching Network
Kim, Yoon-Geon ; Kay, Young-Chul ; Ji, Sung-Hwan ; Choo, Ho-Sung ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 23, issue 1, 2012, Pages 122~130
DOI : 10.5515/KJKIEES.2012.23.1.122
In this paper, we propose a broadband vehicle antenna that can operate at the WiBro band(2.3~2.4 GHz) for a wireless internet service. The feeding of the proposed antenna consists of two T-matching networks on both side of the polyarcylate substrate, and the two T-matching networks are connected through via holes. The designed antenna was built and installed on a rear window of a commercial sedan, and the antenna performances, such as the reflection coefficients and the radiation gain are measured in the open-sight area. The received signal strength of the designed antenna was also tested in a strong field area as well as in a weak field area. The measurement results show the matching bandwidth(
<10 dB) of about 300 MHz in the WiBro band and the average gain of about -5.13 dBi along the azimuth direction.
Bar-Code Shape UHF RFID Tag Antenna
Jeon, Byung-Don ; Chung, You-Chung ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 23, issue 1, 2012, Pages 131~134
DOI : 10.5515/KJKIEES.2012.23.1.131
A bar-code shape UHF RFID tag antenna is designed and fabricated with silver conductive ink. It can be recognize by both bar-code scanner and RFID reader. The bar-code shape is taken from a general box of a product, and the product code of the bar-code is used for the antenna design. The tag antenna is fabricated with silver conductive ink using a T-matching structure. The designed tag antenna is satisfied with bar-code system and RFID system simultaneously. The input reflection coefficient characteristics and the reading range pattern are measured. The peak reading range is about 111 cm, which is long enough.