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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 16, Issue 12 - Dec 2005
Volume 16, Issue 11 - Nov 2005
Volume 16, Issue 10 - Oct 2005
Volume 16, Issue 9 - Sep 2005
Volume 16, Issue 8 - Aug 2005
Volume 16, Issue 7 - Jul 2005
Volume 16, Issue 6 - Jun 2005
Volume 16, Issue 5 - May 2005
Volume 16, Issue 4 - Apr 2005
Volume 16, Issue 3 - Mar 2005
Volume 16, Issue 2 - Feb 2005
Volume 16, Issue 1 - Jan 2005
Selecting the target year
Low Computational Complexity LDPC Decoding Algorithms for DVB-S2 Systems
Jung Ji-Won ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 16, issue 10, 2005, Pages 965~972
In this paper, we first review LDPC codes in general and a belief propagation algorithm that works in logarithm domain. LDPC codes, which is chosen for second generation digital video broadcasting standard, are required a large number of computation due to large size of coded block and iteration. Therefore, we presented two kinds of low computational algorithm for LDPC codes. First, sequential decoding with partial group is proposed. It has same H/W complexity, and fewer number of iteration's are required at same performance in comparison with conventional decoder algerian. Secondly, early detection method for reducing the computational complexity is proposed. Using a confidence criterion, some bit nodes and check node edges are detected early on during decoding. Through the simulation, we knew that the iteration number are reduced by half using subset algorithm and computational complexity of early detected method is about
offs in case of check node update,
offs in case of check node update compared to conventional scheme.
Design of a Modified Half Wavelength Loaded Line Antenna Controllable Resonant Frequency and Input Impedance
Jung Woo-Jae ; Jung Byungwoon ; Kang Gi-Cho ; Park Myun-Joo ; Lee Byungje ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 16, issue 10, 2005, Pages 973~981
A modified half wavelength loaded line antenna is designed and implemented for mobile terminal applications. The antenna is constructed with a radiating element of half wavelength loaded line structure, dielectric substrate, feeding post and two shorting posts on the experimental PCB. The shorting posts are located at each side of the radiating element and lumped inductance elements are on between each shorting post and ground of PCB. By controlling value of inductors, one can adjust resonant frequency and input impedance respectively. Within inductance value of 12 nH, the antenna can have wide operating range of
and good impedance matching. The measured peak gains are between -0.45 dBi and 2.03 dBi for the operating band.
An Analytic Solution of a Circular Aperture Antenna with a Feed Transition
Lee Haeng-Seon ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 16, issue 10, 2005, Pages 982~988
An analytic solution of circular aperture antenna with a feed transition is presented using a hybrid method of generalized scattering matrices and integral transform. The method can give an analytic solution to antennas with integrated filters or mode converters, etc. Scattering matrices and integral transform techniques are combined to accommodate discontinuities connected between an aperture and a feed waveguide, and radiated field from the aperture. The method gives radiation fields as well as return losses of the antenna.
Design of Absorptive Type SPST MMIC Switch for MSM of Satellite Communication
Yom In-Bok ; Ryu Keun-Kwan ; Shin Dong-Hwan ; Lee Moon-Que ; Oh Il-Duck ; Oh Seung-Hyeub ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 16, issue 10, 2005, Pages 989~994
A MMIC(Monolithic Microwave Integrated Circuit) switch chip using InGaAs/GaAs p-HEMT process has been designed for MSM(Microwave Switch Matrix) of satellite communication system. An absorptive type MMIC switch is adopted for good reflection coefficients performances of input and output ports at both on and off states. And, a quarter wavelength impedance transformer is realized with lumped elements of MIM capacitor and spiral inductor for 3 GHz band to reduce the chip size. This MMIC switch covers the frequency range of
. According to the on-wafer measurement, the fabricated MMIC switch with miniature size of
demonstrates insertion loss below 2 dB and isolation above 56.8 dB, and the performance coincides with simulation results.
A New PAR Reduction Scheme in OFDM Systems by PTS Using Genetic Algorithm
Kim Sung-Soo ; Kim Myoung-Je ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 16, issue 10, 2005, Pages 995~1002
An orthogonal frequency division multiplexing(OFDM) system has the problem of the peak-to-average power ratio(PAR). In general, in order to obtain optimal PAR reduction using the partial transmitted sequence(PTS), the total search for the number of sub-blocks and the rotation factors must be accomplished. As the number of sub-blocks and rotation factors increases, PAR reduction improves, such that complexity increases exponentially and the process delay occurs simultaneously. Therefore a technique that reduces PAR, which is almost close to optimal, and the amount of calculation is desired. In this paper a new method using genetic algorithm(GA), which is widely used to search for a point that is globally optimal in many problems, is proposed to search for a rotation factor that reduces simultaneously both the PAR and the amount of calculation, such that the complexity of calculation and the process time are reduced at the same time, Comparison is performed between the proposed method and the various techniques developed previously. The superiority of proposed method is presented by demonstrating the reduction of complexity while a similar PAR reduction is obtained.
Design of Small-Size High-Power SPDT PIN Diode Switch with Defected Ground Structure for Wireless Broadband Internet Application
Kim Dong-Wook ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 16, issue 10, 2005, Pages 1003~1009
In this paper, small-size high-power single pole double throw(SPDT) switch with defected pound structure(DGS) is presented for wireless broadband internet application. To reduce the circuit size using slow-wave characteristic, the DGS is applied to
transmission line of the switch and the measured results are compared with them of conventional switch. To secure high degree of isolation, the switch with the DGS is composed of shunt-connected PIN diodes and shows insertion loss of 0.8 dB and isolation more than 50 dB at 2.3 GHz. The size of the switch is reduced about
only with the DGS patterns while it has very similar performance to the conventional shunt-type switch.
Neural Network Modeling of Memory Effects in RF Power Amplifier Using Two-tone Input Signals
Hwangbo Hoon ; Kim Won-Ho ; Nah Wansoo ; Kim Byung-Sung ; Park Cheonsuk ; Yang Youngoo ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 16, issue 10, 2005, Pages 1010~1019
In this paper, we used neural network technique to model memory effects of RF power amplifier which is fed by two-tone input signals. The memory effects in power amplifier were identified by observing the unsymmetrical distribution of IMD(Inter-Modulation Distortion) measurements with the change of tone spacings and power levels. Different asymmetries of IMD were also found at different center frequencies. We applied TDNN technique to model LDMOS power amplifier based on two tone IMD data, and the accuracy was very high compared to other modeling methods such as the(memoryless) adaptive modeling method.
An Implementation of Miniature RF Transmitter Module for ITS Applications by Using LTCC Technique
Yun Gi-Ho ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 16, issue 10, 2005, Pages 1020~1027
In this paper, economic miniature RF transmitter module for intelligent transportation system(ITS) is described. This module which consists of ASK modulator, frequency synthesizer, power amplifier is operating at 5.8 GHz frequency band and implemented by using LTCC process technique. Thus, ultra small size of 0.8 CC and improved electrical performances has been obtained. From the test results, transmitting characteristics of 10 dBm ouput power and -46 dBc interchannel interference with 1.024 Mbps ASK modulated have been shown. Frequency synthesizer as a transmitting signal source reveals very short locking time of 26 usec and outstanding phase noise of -115 dBc/Hz at 1 MHz offset from 5.8 GHz center frequency.
Reduced Computation Using the DFT Property in the Phase Weighting Method
Ryu Heung-Gyoon ; Hieu Nguyen Thanh ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 16, issue 10, 2005, Pages 1028~1035
OFDM system has high PAPR(Peak-to-Average-Power Ratio) problem. In this paper, we present a low complexity phase weighting method to reduce the computational quantity so that we can cut down the processing time of SPW method. Proposed method is derived from the DFT property of periodical sequences by which PAPR can be reduced efficiently. The simulation results show the same PAPR reduction efficiency of proposed method in comparison with conventional methods. It can reduce 2.15 dB of PAPR with two phase factors and 3.95 dB of PAPR with four phase factors. The computation analysis shows significant improvement in the low complexity phase weighting method.
Analysis of Crosstalk Reduction by Metal Filled Via Hole Fence in Bent Transmission Lines
Kim Jong-Ho ; Han Jae-Kwon ; Park Dong-Chul ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 16, issue 10, 2005, Pages 1036~1042
The crosstalk between bent transmission lines and the effects of additional trace with the metal filled via holes on alleviating the crosstalk are investigated using the circuit concept approach for transmission line sections and impedance modeling for via hole sections. All sections are represented by ABCD matrices and then cascaded. Finally the calculated results by proposed method are confirmed that they agree with the measured results in less than 3 dB except a band of low frequency.
Phase Noise Compensation in OFDM Communication System by STFBC Method
Li Yingshan ; Ryu Heung-Gyoon ; Jeong YoungHo ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 16, issue 10, 2005, Pages 1043~1049
In OFDM system suitable for high capacity high speed broadband transmission, ICI caused by phase noise degrades system performance seriously by destroying the orthogonality among subcarriers. In this paper, a new STFBC method combining ICI self cancellation scheme and antenna, time, frequency diversity is studied to reduce ICI effectively. CPE and ICI are analyzed by the phase noise linear approximation method in the proposed STFBC OFDM system. CIR, PICR and BER are discussed to compare the system performance degraded by phase noise of PLL. As results, STFBC method significantly reduces ICI. Furthermore, the SCI that usually happens in the traditional STBC, SFBC diversity coding method can be easily avoided.
Broadband LTCC Receiver Module for Fixed Communication in 40 GHz Band
Kim Bong-Su ; Kim Kwang-Seon ; Eun Ki-Chan ; Byun Woo-Jin ; Song Myung-Sun ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 16, issue 10, 2005, Pages 1050~1058
This paper presents how to design and implement a very compact, cost effective and broad band receiver module for IEEE 802.16 FWA(Fixed Wireless Access) in the 40 GHz band. The presented receiver module is fabricated in a multi-layer LTCC(Low Temperature Cofired Ceramic) technology with cavity process to achieve excellent electrical performances. The receiver consists of two MMICs, low noise amplifier and sub-harmonic mixer, an embedded image rejection filter and an IF amplifier. CB-CPW, stripline, several bond wires and various transitions to connect each element are optimally designed to keep transmission loss low and module compact in size. The LTCC is composed of 6 layers of Dupont DP-943 with relative permittivity of 7.1. The thickness of each layer is 100 um. The implemented module is
in size and shows an overall noise figure of 4.8 dB, an overall down conversion gain of 19.83 dB, input P1 dB of -22.8 dBm and image rejection value of 36.6 dBc. Furthermore, experimental results demonstrate that the receiver module is suitable for detection of Digital TV signal transmitted after up-conversion of
band to 40 GHz.