Go to the main menu
Skip to content
Go to bottom
REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
> Journal Vol & Issue
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 14, Issue 12 - Dec 2003
Volume 14, Issue 11 - Nov 2003
Volume 14, Issue 10 - Oct 2003
Volume 14, Issue 9 - Sep 2003
Volume 14, Issue 8 - Aug 2003
Volume 14, Issue 7 - Jul 2003
Volume 14, Issue 6 - Jun 2003
Volume 14, Issue 5 - May 2003
Volume 14, Issue 4 - Apr 2003
Volume 14, Issue 3 - Mar 2003
Volume 14, Issue 2 - Feb 2003
Volume 14, Issue 1 - Jan 2003
Selecting the target year
Radially Corrugated Circular Microstrip Patch Antenna for Miniaturization
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 14, issue 12, 2003, Pages 1233~1238
In this paper, radially corrugated circular-type microstrip patch antenna was devised and manufactured for GPS (center frequency: 1.575 GHz). Radially corrugated circular-type microstrip patch antenna having radiational corrugation-patch contributed to add size reduction ratio by lowering the resonant frequency because the edge current also has the extended and perpendicular path. As a result, radially corrugated circular-type microstrip patch antenna has 28 % area reduction than planer circular-type patch antenna for linear polarization and 27.7 % area reduction than planer circular-type patch antenna for circular polarization. Radially corrugated circular-type microstrip patch antenna is suitable for miniaturized receive antenna for GPS which has the characteristic of gain 2.1 dBd, axiai ratio 1.3 dB, 2 dB axial bandwidth 15 MHz(0.9 %).
Dummy Sequence Insertion for PAPR Reduction of OFDM Communication System
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 14, issue 12, 2003, Pages 1239~1247
OFDM(orthogonal frequency division multiplexing) communications system is very attractive for the high data rate transmission in the frequency selective lading channel. Since OFDM has high PAPR(peak-to-average power ratio), OFDM signal may be distorted by the nonlinear HPA(high power amplifier). In this paper, we propose the DSI(dummy sequence insertion) method for OFDM communication system. Some sub-carriers are inserted for PAPR reduction. They carry the specified dummy data sequence which are used for only PAPR reduction and do not work as side information like the conventional PTS(partial transmit sequence) or SLM(selected mapping) method. We use the complementary sequence and the combination of the correlation sequence as the dummy sequence. Flipping technique is used for the DSI method to get the effective PAPR reduction. It is important that BER of the proposed method is independent of the damage of the dummy data sequence. And DSI method has better spectral efficiency than the conventional block coding. On the other hand, threshold PAPR method is applied to cut down the processing time. However, this DSI method is not better than the conventional PTS method in the respect of the PAPR reduction performance. The DSI method includes the threshold PAPR lower than the PAPR of the OFDM signal, reduces the processing time and improves the BER performance.
An FPGA Design of High-Speed QPSK Demodulator
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 14, issue 12, 2003, Pages 1248~1255
High-speed QPSK demodulator has been one important design objective of any wireless communication systems, especially those offering broadband multimedia service. This paper describes Zero-Crossing IF-level(ZCIF) QPSK demodulator for high-speed wireless communications, and its hardware structures are discussed. ZCIF QPSK demodulator is mainly composed of symbol time circuit and carrier recovery circuit to estimate timing and phase-offsets. There are various schemes. Among them, we use Gardner algorithm and Decision-Directed carrier recovery algorithm which is most efficient scheme to warrant the fast acquisition and tracking to fabricate FPGA chip. The testing results of the implemented onto CPLD-FLEX10K chip show demodulation speed is reached up to 2.6［Mbps］. Actually in case of designing by ASIC, its speed may be faster than CPLD by 5 times. Therefore, it is possible to fabricate the ZCIF QPSK demodulator with speed of 10 Mbps.
VHDL Design of Pragmatic Trellis Coded Modulation for Adaptive Satellite Broadcasting
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 14, issue 12, 2003, Pages 1256~1263
In this paper, we analyzed the channel coding scheme of DVB and ISDB standard for high-speed satellite broadcasting. Also, this paper proposed optimal parameters of decoder with variable coding rate for implementation. According to the optimal parameters, the pragmatic TCM of rate 213, 5/6, 819 was modeled by VHDL. The results designed by VHDL can be verified.
NRD Guide Stepped-Impedance Duplexer in Millimeter Wave Band
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 14, issue 12, 2003, Pages 1264~1268
In this paper, we have designed the duplexer using non-radiative dielectric(NRD) guide in millimeter wave band. The designed duplexer is composed of two stepped-impedance filters and T-junction. Stepped-impedance filters we designed with an equivalent circuit model of evanescent waveguide and the T-junction is optimized to minimize return loss of -20 dB or more. The characteristics of duplexer show good agreements with the expected results.
Non-Radiative Dielectric(NRD) Rotman Lens with Gap-Coupled Unidirectional Dielectric Radiator(UDR)
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 14, issue 12, 2003, Pages 1269~1275
In this paper, nonradiative dielectric(NRD) rotman lens with a gap-coupled unidirectional dielectric radiator(UDR) has been designed. Gap-coupled UDR is structurally suitable for NRD rotman lens. We have optimized NRD rotman lens for minimizing side-lobe, and calculated design parameters of UDR such as length of resonator and distance of gap using an equivalent circuit model of an evanescent NRD guide. Experimental prototype of UDR is fabricated and measured at the center frequency of 38 GHz. The simulated S-parameter and far-field radiation beam pattern of UDR show good agreements with measured data. Finally, total beam pattern of NRD rotman lens of multi-beam feed has been obtained using a measured pattern of UDR and array factor of NRD rotman lens. The obtained beam pattern shows remarkably suppressed side-lobe.
Power Bus Noise Analysis on IC using Wide-Band Ferrite Bead Model
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 14, issue 12, 2003, Pages 1276~1282
The SMT(Surface Mount Type) ferrite bead used to reduce the influx of power bus noise is modeled with parallel capacitor(C), series resistor(R) and series inductor(L). The simple equivalent circuit modeling doesn't agree with the measurement result. In this paper, we proposed the accurate equivalent circuit model of the ferrite bead at wide frequency range(50 MHz∼3 GHz) and analyzed the noise effect to the high speed IC(Integrate Circuit) with ferrite bead or not.
A Study on the Efficient Synthesis of Nonuniform Transmission Line Filters using Zakharov-Shabat Coupled Mode Equation
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 14, issue 12, 2003, Pages 1283~1291
Nonuniform transmission lines(NTLs) with the desired frequency response can be realized by synthesizing the potential from the coupled mode Zakharov-Shabat(ZS) equation in the one-dimensional inverse scattering problem. In this study, an efficient synthesis method using the ZS equations is presented for NTLs with arbitrarily specified reflection coefficients which take the restricted potential. This method lessens the line length which plague conventional design schemes using specific windows for reflection coefficients. Furthermore solving the ZS inverse transform problem is simplified by adopting the successive approach instead of the conventional iterative method. The proposed method is compared with the conventional method using specific windows by applying to design of dispersive NTL filters, and verified by two-port analysis through the chain matrix.
Study on the Fabrication of the Low Loss Transmission Line and LPF using MEMS Technology
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 14, issue 12, 2003, Pages 1292~1299
In this paper, we fabricated new GaAs-based dielectric-supported air gapped microstriplines(DAMLs) using the surface MEMS and the LPF for Ka-band using the fabricated DAMLs. We elevated the signal lines from the substrate, in order to reduce the substrate dielectric loss and obtain low losses at millimeter-wave frequency band with wide impedance range. We fabricated LPF with DAMLs for Ka-band. Due to reducing the dielectric loss of DAMLs, the insertion loss of LPF can be reduced. Miniature is essential to integrate LPF with active devices, so that we fabricated LPF with the slot on the ground to reduce the size of the LPF. We compared a characteristic to LPF with the slot and LPF without the slot.
Performance Analysis of Multicarrier CDMA System with Adaptive Modulators in Rayleigh Fading Channel
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 14, issue 12, 2003, Pages 1300~1310
In this paper, the performance of a multicarrier CDMA system using adaptive modulation and adaptive subchannel allocation scheme is analyzed in Rayleigh fading channel. The proposed adaptive modulator consists of modulation schemes using QPSK 16 QAM, 64 QAM and 256 QAM and constellations are pointed by Gray code. In addition, the threshold of the analysis is average E
o/ when the BER is 1 %. In the multicarrier system with adaptive subchannel allocation scheme, each DS waveform of user is transmitted over the K subchannels with the biggest fading among L subchannels. In case of the proposed system, total 4 subchannels are used and data are transmitted over 2 subchannels with the biggest fading, which results in the threshold of each channels is 5.2 dB, 9 dB, 13.2 dB and 8.4 dB, 12.2 dB, 16.3 dB. In the case of proposed system, the BER of 10
-3/ is satisfied if average E
o/ is 8.1 dB. This is increased performance of 12.9 dB in comparison with conventional system. The BPS according to average channel is needed average E
o/ of about 15 dB in 7 bit. In the case of subchannel error, the BER of 10
-3/ is 13.6 dB and is declined about 5.5 dB.
The Statistical Technique for Dosimetric Meta-Analysis at in-vivo and in-vitro Papers about Bioeffects of RF Electromagnetic Field
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 14, issue 12, 2003, Pages 1311~1320
This paper proposed the estimating method of electromagnetic dosimetric reliability at in-vivo and in-vitro experiments. For more accurate consequences of these researches, we have tried to find out any correlations among output power, power density and specific absorption rate(SAR) with the results of in-vivo, in-vitro tests and SAR reports of cellular phone and PDA. In the case of in-vivo tests, the power density has close statistical correlations with SAR value and in the event of in-vitro tests, the output power has considerable statistical correlations with SAR containing duty factor. We analysed the coefficient of determination to estimate the dosimeoic uncertainty. If we use this method before evaluating techniques of measurement and analysis at both in-vivo and in-vitro experiments, we will conduct more accurate reliability test.
CPW Directional Couplers with Enhanced Directivity Via Center-Elimination of Backed Conductor
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 14, issue 12, 2003, Pages 1321~1328
In this paper, we demonstrate that the directivity of the CPW(Coplanar Waveguide) directional coupler with finite-extent backed conductor is enhanced by eliminating center region of backed conductor appropriately. If the backed conductor is removed at center region of couplers, the couplers have two backed conductors. If effective odd mode dielectric constant is decreased at center region, the electrical length for odd mode is changed and phase velocity is same at the directional couplers. Hence, directivity is improved. The eliminated length is solved by an odd and even mode analysis. The designed moderate CPW directional coupler with the proposed compensation structure has excellent directivity and matching characteristic at center frequency in simulation and measurement.
Development of Composite Ba Ferrite EM Wave Absorbers for GHz Frequency
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 14, issue 12, 2003, Pages 1329~1334
We prepared EM wave absorbers by using recycled Ba ferrite far GHz frequency, and investigated the effects of carbon additions and preparation temperatures on their EM wave absorption properties. We clarified that it is very important to consider carbon amounts in Ba ferrite and preparation temperature for Ba ferrite EM wave absorbers with high quality.
Design of a Single-Balanced Diode Mixer of FMCW Radar for Vehicle Detection
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 14, issue 12, 2003, Pages 1335~1340
In this paper, a single balanced diode Mixer for the homodyne FMCW radar to detect distance and velocity of a vehicle target is designed and implemented using a microstrip line and two schottky barrier beam lead diodes. This mixer is optimally designed to have less a conversion loss within the 100 MHz bandwidth with a little LO injection power and a higher LO isolation as soon as possible through the embedded electrical length of microsrtrip line placed between the coupler and diode matching, considering together LO matching condition. The measured results show 6 dB of conversion loss, 23 dB LO/RF isolation and 3 dBm of input 1l dB, respectively.