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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 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
20 GHz Pulse Sampling Oscilloscope Based on Electro-Optic Technique
Lee, Dong-Joon ; Kang, No-Weon ; Lee, Joo-Gwang ; Kang, Tae-Weon ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 22, issue 10, 2011, Pages 927~933
DOI : 10.5515/KJKIEES.2011.22.10.927
This paper presents an optical sampling technique which can be used to overcome the limited bandwidth of a commercial electronic sampling oscilloscope for pulsed signal measurement. Employing an ultrafast laser with 0.1 ps pulse duration, 20 GHz electromagnetic pulses were generated through a fast photodiode. These pulses were transmitted through a microstrip line and sampled with an optically triggered electro-optic system. Two sampled 20 GHz pulses - measured independently over the transmission line with a non-contacting electro-optic method and conventional electronic one through a coaxial cable - were compared.
Reconfigurable Beam Steering Antenna Using Superposed Beam of Double Loops
Kim, Jae-Young ; Jung, Chang-Won ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 22, issue 10, 2011, Pages 934~940
DOI : 10.5515/KJKIEES.2011.22.10.934
A novel reconfigurable beam steering antenna using double loops is proposed. The double loop antenna has a superposed beam which is produced by combining the in-phase beam in the inner loop with the out-of-phase beam in the outer loop. Also, the doble loop antenna uses two artificial switches to connect between inner loop and outer loop, and has the beam directions of three separate cases(Case 1, Case 2, Case 3) by changing ON/OFF states of switches. The operation frequency of the antenna is 14.5 GHz, and three maximum beam directions of the antenna are
(Case 2) and
(Case 3). The peak gains of each case are 6.5 dBi(Case 1), 7.6 dBi(Case 2) and 7.8 dBi(Case 3). The half power beam width(HPBW) of each case is
, and the overall HPBW is
Performance Analysis of Incremental Cooperative Communication with Relay Selection Based on The Relays Arrangement
Kim, Lyum ; Kong, Hyung-Yun ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 22, issue 10, 2011, Pages 941~950
DOI : 10.5515/KJKIEES.2011.22.10.941
In this paper, we analysis the end-to-end performance of the incremental cooperative communication with relay selection. In the conventional cooperative scheme, the source(S) broadcasts the signal to the relay(R) and the destination(D) at 1st phase, and the R forwards the signal to the D at 2nd phase. Although this scheme can improve performance and provide diversity gain, it suffers from decreasing spectrum efficiency. In order to overcome this problem, the incremental cooperative model can be used. In this paper, we study two incremental cooperative method : the first uses ARQ with threshold SNR and the second uses HARQ with channel coding. we also evaluated performance of the incremental cooperative communication based on the R arrangement by using both methods.
Design and Performance Evaluation of OFDM-Based Low Power Communication System
Choi, Jae-Hoon ; Ryu, Heung-Gyoon ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 22, issue 10, 2011, Pages 951~959
DOI : 10.5515/KJKIEES.2011.22.10.951
The low power consumption modulation is required for short range communication. In this paper, we analyze performance of low power consumption modulation scheme such as PSPM, PSSK and QAPM using OFDM transmission in AWGN channel. A PSPM, PSSK and QAPM modulation scheme are decrease in bandwidth efficiency but improved power efficiency than existing PSK and QAM. These modulation schemes can achieve power efficiency because every symbol of modulations has a zero-envelope period like PPM techniques. The OFDM system is high bandwidth efficiency than single carrier system. In this paper, we are propose the frequency domain mapping method for OFDM transmission using low power consumption modulation method. Also, we compare low power OFDM communication system regard to BER performance, throughput and PAPR.
Derivation of the ML Based Monopulse Ratio Curve
Lim, Jong-Hwan ; Kim, Heung-Su ; Yang, Hoon-Gee ; Chung, Young-Seek ; Bae, Kyung-Bin ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 22, issue 10, 2011, Pages 960~965
DOI : 10.5515/KJKIEES.2011.22.10.960
This paper presents the mathematical derivation of a maximum likelihood(ML)-based monopulse ratio(MR) curve. The derived form is, with the linear array assumed, shown to be the function of the number of array elements and the elements' spacing. Through some simulations, the acquired form is equivalent to the expected MR curve. Furthermore, we show the form, which consists of several terms, can be simplified by one tangent function.
Radar Return Signal Simulation Equipment Using MC-DDS (Multi-Channel Direct Digital Synthesis)
Roh, Ji-Eun ; Yang, Jin-Mo ; Yoo, Gyung-Joo ; Gu, Young-Suk ; Lee, Sang-Hwa ; Song, Sung-Chan ; Lee, Hee-Young ; Choi, Byung-Gwan ; Lee, Min-Joon ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 22, issue 10, 2011, Pages 966~980
DOI : 10.5515/KJKIEES.2011.22.10.966
Radar receiving echo signal provides target information - range, velocity and position by signal magnitude and Doppler shift, which are determined by target reflection characteristics and target maneuver. Target angle error is extracted from the magnitude ratio of difference channel to sum channel. In this paper, we introduce a radar Return Signal Simulation Equipment(RSSE) which is implemented for the purpose of performance analysis and evaluation of phased array multi-function radar(MFR). It generates multi-target environment with jamming signals using MC-DDS (Multi-Channel Direct Digital Synthesis), and has scalability by using the efficient hardware configuration. The performance of the developed RSSE has been evaluated under various test environments. Especially, we proved that required target detection performance is achieved by RSP(Radar Signal Processor) interfaced RSSE configuration.
Performance Improvement of Radar Target Classification Using UWB Measured Signals
Lee, Seung-Jae ; Lee, Sung-Jun ; Choi, In-Sik ; Park, Kang-Kuk ; Kim, Hyo-Tae ; Kim, Kyung-Tae ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 22, issue 10, 2011, Pages 981~989
DOI : 10.5515/KJKIEES.2011.22.10.981
In this paper, we performed radar target classification for the five scale models using ultra-wideband measured signal. In order to compare the performance, the 2 GHz(2~4 GHz), 4 GHz(2~6 GHz), and 6 GHz(2~8 GHz) bandwidth were used. Short time Fourier transform(STFT) and continuous wavelet transform(CWT) are used for target feature extraction. Extracted feature vectors are used as input for the multi-layerd perceptron(MLP) neural network classifier. The results show that as the bandwidth is wider, the performance is better.
A Single Layer Multi Band Microstrip Patch Antenna for GPS L1/L2, GLONASS Receiver Applications
Kim, Ji-Hae ; Kim, Mi-Suk ; Kim, Jong-Seong ; Son, Seok-Bo ; Kim, Young-Baek ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 22, issue 10, 2011, Pages 990~998
DOI : 10.5515/KJKIEES.2011.22.10.990
In this paper, we have designed a multi-band single layer microstrip patch antenna with slots for GPS L2/L1, GLONASS receivers. The antenna has dual feed structure and consists of single layer microstrip patch with slots and impedance matching circuit. The antenna specifications are a VSWR(Voltage Standing Wave Ratio) of less than 2.0, RHCP(Right-Hand Circular Polarization) characteristics over the operating frequency bands of GPS L2(1,227.6 MHz)/L1(1,575.42 MHz) and GLONASS(1,602 MHz), the maximum active antenna gain of more than 30 dB and the axial ratio of less than 3 dB. The antenna has been successfully evaluated by various tests.
Mutual Inductance Calculation and Analysis between Two Circular Coils of Perpendicular Arrangement
Kim, Jin-Wook ; Son, Hyeon-Chang ; Kim, Do-Hyeon ; Kim, Kwan-Ho ; Park, Young-Jin ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 22, issue 10, 2011, Pages 999~1004
DOI : 10.5515/KJKIEES.2011.22.10.999
In this paper, calculation method of mutual inductance for two circular coils which are widely used in wireless power transfer system and analysis results using the method are proposed. Two circular coils are arranged in a perpendicular way. For calculation of the mutual inductance, an Rx coil placed perpendicularly with the other coil is uniformly subdivided into many unit cells and both magnetic flux density linked with the Rx coil at each unit cell and the total magnetic flux density of the Rx coil are obtained. Two circular coils are considered as a filamentary coil and uniform current density on each coil is assumed. For verification, helical and spiral coils are fabricated. As a result of measurement in 50 cm to 100 cm distance, theoretical mutual inductance is almost agreed with measured one.
Transient Analysis of General Dispersive Media Using Laguerre Functions
Lee, Chang-Hwa ; Kwon, Woo-Hyen ; Jung, Baek-Ho ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 22, issue 10, 2011, Pages 1005~1011
DOI : 10.5515/KJKIEES.2011.22.10.1005
In this paper, we present a marching-on-in-degree(MOD) finite difference method(FDM) based on the Helmholtz wave equation for analyzing transient electromagnetic responses in a general dispersive media. The two issues related to the finite difference approximation of the time derivatives and the time consuming convolution operations are handled analytically using the properties of the Laguerre functions. The basic idea here is that we fit the transient nature of the fields, the flux densities, the permittivity with a finite sum of orthogonal Laguerre functions. Through this novel approach, not only the time variable can be decoupled analytically from the temporal variations but also the final computational form of the equations is transformed from finite difference time-domain(FDTD) to a finite difference formulation through a Galerkin testing. Representative numerical examples are presented for transient wave propagation in general Debye, Drude, and Lorentz dispersive medium.
A New Bussgang Blind Equalization Algorithm with Reduced Computational Complexity
Kim, Seong-Min ; Kim, Whan-Woo ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 22, issue 10, 2011, Pages 1012~1015
DOI : 10.5515/KJKIEES.2011.22.10.1012
The decision-directed blind equalization algorithm is often used due to its simplicity and good convergence property when the eye pattern is open. However, in a channel where the eye pattern is closed, the decision-directed algorithm is not guaranteed to converge. Hence, a modified Bussgang-type algorithm using a hyperbolic tangent function for zero-memory nonlinear(ZNL) function has been proposed and applied to avoid this problem by Filho et al. But application of this algorithm includes the calculation of hyperbolic tangent function and its derivative or a look-up table which may need a large amount of memory due to channel variations. To reduce the computational and/or hardware complexity of Filho's algorithm, in this paper, an improved method for the decision-directed algorithm is proposed. In the proposed scheme, the ZNL function and its derivative are respectively set to be the original signum function and a narrow rectangular pulse which is an approximation of Dirac delta function. It is shown that the proposed scheme, when it is combined with decision-directed algorithm, reduces the computational complexity drastically while it retains the convergence and steady-state performance of the Filho's algorithm.
Maximum Electric Field Strength Prediction of WCDMA Base Station Using Pilot Channel
Lee, Yeong-Su ; Yoon, Hyun-Goo ; Jang, Byung-Jun ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 22, issue 10, 2011, Pages 1016~1019
DOI : 10.5515/KJKIEES.2011.22.10.1016
In this paper, we predict a maximum electric field strength of WCDMA base station using a pilot channel in a code domain. In order to verify the feasibility of our method, we compare our predicted value on a self-designed test base station with a general electric field strength measurement value at a full-traffic load condition and with a calculated value by a ray-tracing technique. Predicted results show above 90 % agreement with the general measurement and calculation values. We also show that our prediction method can be applied to electric field measurement on a real operating base station. Therefore, it is concluded that our prediction method be an effective method to measure a maximum electric field strength in a base station inspection test.
M-QAM Symbol Remapping Using LLR Soft Bit Information for Iterative Equalization
Kim, Geun-Bae ; Park, Sang-Kyu ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 22, issue 10, 2011, Pages 1020~1023
DOI : 10.5515/KJKIEES.2011.22.10.1020
In this paper, we present a symbol remapping method of BRGC M-ary QAM signal by using LLR soft bit decision information which is obtained after iterative decoding process. In order to reconstruct estimated transmitted signal constellation, we have to use exponential or hyperbolic tangent(tanh) function resulting in high implementation complexity. The BRGC mapping rule enables us to use a recursive operation. In addtion, we reduce the implementing complexity by using a curve fitting algorithm.