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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 25, Issue 12 - Dec 2014
Volume 25, Issue 11 - Nov 2014
Volume 25, Issue 10 - Oct 2014
Volume 25, Issue 9 - Sep 2014
Volume 25, Issue 8 - Aug 2014
Volume 25, Issue 7 - Jul 2014
Volume 25, Issue 6 - Jun 2014
Volume 25, Issue 5 - May 2014
Volume 25, Issue 4 - Apr 2014
Volume 25, Issue 3 - Mar 2014
Volume 25, Issue 2 - Feb 2014
Volume 25, Issue 1 - Jan 2014
Selecting the target year
Design of Various WBAN Antennas Considering for the Location on a Human Body
Tak, Jinpil ; Choi, Jaehoon ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 25, issue 11, 2014, Pages 1095~1103
DOI : 10.5515/KJKIEES.2014.25.11.1095
WBAN has received great attention recently due to its versatile applicability. In this paper, antennas suitable for WBAN communication depending on the locations of mobile devices and the manufacturing of a human equivalent phantom are introduced. The effect of the body on the communication performance is largely dependent on the locations of devices. Specifically, the radiation and return loss characteristics of the antenna are greatly influenced by the characteristics of a medium existing in the near-field of an antenna. Thus, the proper WBAN antenna design is important in establishing a successful communication link between the transceivers. To consider the effect of the body on the antenna performance, the human equivalent phantom is also important factor in the WBAN antenna design and measurement. In introduction, categorization of the WBAN communication channel is introduced and antenna characteristics required for each communication channel are described. In the main subject section, several WBAN antenna design examples along with the implementation of the human equivalent phantom are discussed. In conclusion, the factors, which have to be considered in the design process, and future research are mentioned.
Design of Deployable Lightweight Antenna for Satellite SAR
Lee, Taek-Kyung ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 25, issue 11, 2014, Pages 1104~1112
DOI : 10.5515/KJKIEES.2014.25.11.1104
We present a design of the deployable lightweight antenna to be used in the satellite satisfying the required performance of the onboard sensor. The analysis is performed on the SAR antenna requirements, deploying techniques including material selection, and the characterization of deployable antenna with central disk. The performance of the solid deployable antennas and the mesh antennas are simulated, and the CFRP(Carbon Fiber Reinforced Plastics) samples are manufactured and tested. It is confirmed that the deployable antennas with central disk can meet the required performance by using deploying panels or mesh.
General Theory for Enhancing the Transmission Efficiency through Small Apertures
Cho, Young-Ki ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 25, issue 11, 2014, Pages 1113~1120
DOI : 10.5515/KJKIEES.2014.25.11.1113
In this paper, general methods for enhancing the transmission efficiency through the small subwavelength aperture in an infinite conducting plane are considered first by use of the transmission-resonant aperture like the ridged circular aperture structure, second by employing the transmission-resonant cavity structure. In particular, the maximum transmission cross section is found to be
for the two structures, where G is the gain of the aperture in the output half space. As experimental works, the impedance matching characteristics are investigated for the cases that above two structures are incorporated as a potential near field microscopic probe in the waveguide end. As a complementary problem to the above transmission-resonant aperture problem, some discussions are also given on the scattering resonance by the scattering object much smaller than the wavelength. This discussion may provide a good understanding of the physics for the phenomena that the maximum scattering cross section is much larger than the physical size of the atom in atomic physics area.
Planar Frequency-Reconfigurable Monopole Antenna Design
Kim, Youngkyu ; Lim, Joingsik ; Han, Sang-Min ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 25, issue 11, 2014, Pages 1121~1127
DOI : 10.5515/KJKIEES.2014.25.11.1121
In this paper, a planar frequency reconfigurable antenna is proposed with variable capacitors. The proposed one is designed with a planar monopole, and varies resonant frequencies by variable capacitive loading of a varactor diode. The equivalent circuit and electromagnetic(EM) simulation are utilized for the analysis at the variable characteristic design of the antenna, and the same radiation performance. The implemented frequency variable monopole antenna has been verified by comparing prototypes with designed capacitors and ones with biased varactor diodes. The proposed antenna has presented the resonant frequency variations from 2.25 GHz to 2.42 GHz.
Analysis of Elements for Efficiencies in Magnetically-Coupled Wireless Power Transfer System Using Metamaterial Slab
Kim, Gunyoung ; Oh, TaekKyu ; Lee, Bomson ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 25, issue 11, 2014, Pages 1128~1134
DOI : 10.5515/KJKIEES.2014.25.11.1128
In this paper, the effects of a metamaterial slab with negative permeability in a magnetically coupled wireless power transfer system (WPT) in the overall performance are analyzed quantitatively in terms of the effective quality factors of the loop resonators and coupling coefficient considering the slab losses, based on an equivalent circuit. Using the ideal metamaterial slab(lossless slab), the WPT efficiency is improved considerably by the magnetic flux focusing. However, the practical lossy slab made of RRs or SRRs limits the significant enhancement of WPT efficiency due to the relatively high losses in the slab consisting of RRs or SRRs near the resonant frequency. For the practical loop resonator, other than a point magnetic charge, using the practical lossy metamaterial slab in order to improve the transfer efficiency, the width of the slab needs to be optimized somewhat less than the half of the distance between two loop resonators. For the low-loss slab with its loss tangent of 0.001, the WPT efficiency is maximized at 93 % when the ratio of the slab width and the distance between the two resonators is approximately 0.35, compared with 53 % for the case without the slab. The efficiency in case of employing the high-low slab(loss tangent: 0.2) is maximized at 61 % when the slab ratio is 0.25.
Realtime Wideband SW DDC Using High-Speed Parallel Processing
Lee, Hyeon-Hwi ; Lee, Kwang-Yong ; Yun, Sangbom ; Park, Yeongil ; Kim, Seongyo ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 25, issue 11, 2014, Pages 1135~1141
DOI : 10.5515/KJKIEES.2014.25.11.1135
Performing wideband DDC while quantizing signal over a wide dynamic range and high speed sampling rate have primarily been implemented in a hardware such as, FPGA or ASIC because of time-consuming job. Real-time wideband DDC SW, even though signal environment changes, adapt to signal environment flexibly and can be reused. In addition, it has a lower price than the hardware implementation. In this paper, we study the system design that can be stored in real time designing a high-speed parallel processing architecture for SW-based wideband DDC. Finally, applying a Ping-Pong Buffering mechanism for receiving a signal in real time and CUDA for a high-speed signal processing, we verify wideband DDC design procedure that meets the signal processing.
TC & R Communication Link Performance Analysis of Geostationary Satellite Employing PCM/PSK/PM on Super Synchronous Transfer Orbit
Lee, Sun-Ik ; Yeom, Kyung-Whan ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 25, issue 11, 2014, Pages 1142~1155
DOI : 10.5515/KJKIEES.2014.25.11.1142
The classical PCM/PSK/PM scheme has been commonly used for TC & R applications between satellites and ground stations in the S-band. We analyzed TC & R link performance between ground station and the geostationary satellite which employs PCM/PSK/PM, when the satellite are particularly on the Super Synchronous Transfer Orbit(SSTO). The satellite parameters on SSTO are assumed to be those operating on the geostationary orbit, considering heritage aspect. In the uplink, the results shown indicate that sufficient margins over 3 dB are obtained when the EIRP of ground station is greater than 65 dBW. The down link performance is of great interest. By adjusting the telemetry modulation index and ranging modulation index, we could obtain the required margin of 3.0 dB in the down link, and find out the minimum G/T of ground station. In conclusion, the previously operated ground stations during LEOP at COMS launch, can be operational when GEO injection is made using SSTO(65,000 km and 70,000 km).
Shielding Effect Analysis of Communication Cables Using EN50289 for Transfer Impedance Measurement of Coaxial Cable
Lee, Keunbong ; Zhang, Nan ; Jeon, Jiwoon ; Song, Seungje ; Nah, Wansoo ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 25, issue 11, 2014, Pages 1156~1163
DOI : 10.5515/KJKIEES.2014.25.11.1156
In this work by measuring transfer impedance of communication cables using EN50289 its Shielding effect is analyzed. transfer impedance measurement triaxial method using EN50289 is defined in CENELEC, it is unlike triaxial method prescribed in IEC Standard 96-1, can be measured regardless of diameter of coaxial cable and outer conductor. in this paper, transfer impedance measurement device of coaxial cable is designed and made according to EN50289 standard, The analysis determines the reliable working frequency range of coaxial cable and examined the impact of different shielding methods on coaxial cable. The transfer impedance measurements show considerable variations in results with various shielding methods. also the measurement procedure is verified through comparison of calculated and measured transfer impedance of RG-58 cable.
BCI Probe Emulator Using a Microstrip Coupler
Jung, Wonjoo ; Kim, SoYoung ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 25, issue 11, 2014, Pages 1164~1171
DOI : 10.5515/KJKIEES.2014.25.11.1164
Bulk Current Injection(BCI) test is a method of injecting current into Integrated Circuit(IC) using a current injection probe to qualify the standards of Electromagnetic Compatibility(EMC). This paper, we propose a microstrip coupler structure that can replace the BCI current injection probe that is used to inject a RF noise in standard IEC 62132-part 3 documented by International Electrotechnical Commission. Conventional high cost BCI probe has mostly been used in testing automotive ICs that use high supply voltage. We propose a compact microstrip coupler which is suitable for immunity testing of low power ICs. We tested its validity to replace the BCI injection probe from 100 MHz to 1,000 MHz. We compared the power[dBm] that is needed to generate the same level of noise between current injection probe and microstrip coupler by sweeping the frequency. Results show that microstrip coupler can inject the same level of noise into ICs for immunity test with less power.
Prediction of Noise Power Disturbance from Antenna to Transmission Line System
Ryu, Soojung ; Jeon, Jiwoon ; Kim, Kwangho ; Jo, Jeongmin ; Lee, Seungbae ; Kim, SoYoung ; Nah, Wansoo ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 25, issue 11, 2014, Pages 1172~1182
DOI : 10.5515/KJKIEES.2014.25.11.1172
In these days, many kinds of goods are more light and more integrated. As frequency range of mobile applications have increased to improve performance of antenna furthermore, EMI(ElectroMagnetic Interference) problem has frequently caused by disturbance of antenna in device which aggravates other circuit. This paper proposes a technique for the prediction of noise power to the transmission line from antenna located near the line. Although noise power transferred to transmission line is varied by source impedance of antenna and load impedance of transmission line basically, the power magnitude can be presented in a square form of S-parameter between antenna and transmission line due to small variation of transferred power. For this reason, we can use the index expressed the transferred power varied along geometrical shapes of transmission line. As a result, big difference is occurred along location of antenna especially the bended line. And this such experiment is correspond with simulation, these results have meaning physically considering electromagnetic field distribution in near and far field. HFSS of Ansys and CPW with ground is used in this paper.
Accuracy Examination in the RCS Computation of a Leaf Using the Resistive Sheet Technique with Various Thicknesses and Moisture Contents
Park, Minseo ; Kim, Han-Joong ; Um, Kwiseob ; Park, Sin-Myong ; Kweon, Soon-Koo ; Oh, Yisok ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 25, issue 11, 2014, Pages 1183~1189
DOI : 10.5515/KJKIEES.2014.25.11.1183
The accuracy of the resistive-sheet technique in calculating the RCS(Radar Cross Section) of a deciduous leaf is examined in this paper for various thicknesses and dielectric constants, and a range of thicknesses for the resistive sheet technique is proposed. At first, a leaf was assumed to be a lossy dielectric disk, and the dielectric disk was again assumed to be a resistive sheet with an appropriate resistivity for a given thickness, a dielectric constant, and a frequency. Then, the RCS of the leaf was computed using the physical optics(PO) method, and was compared with the calculation results of a numerical analysis: i.e., a commercial tool based on the FEM (Finite Element Method) technique. It was shown that the error increases as the thickness increases. The error was 0.1 dB, for example, when the thickness is 1.2 mm and 3.7 dB when the thickness is 3 mm with a dielectric constant of(21.4, 9.7) at 9.6 GHz. It was also found that the error decreases as the dielectric constant increases. This study will be very useful for calculating the scattering characteristics of numerous leaves in a vegetation canopy for estimating its radar backscatter using scattering model.
Design of the Transceiver for a Wide-Range FMCW Radar Altimeter Based on an Optical Delay Line
Choi, Jae-Hyun ; Jang, Jong-Hun ; Roh, Jin-Eep ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 25, issue 11, 2014, Pages 1190~1196
DOI : 10.5515/KJKIEES.2014.25.11.1190
This paper presents the design of a Frequency Modulated Continuous Wave(FMCW) radar altimeter with wide altitude range and low measurement errors. Wide altitude range is achieved by employing the optic delay in the transmitting path to reduce the dynamic range of measuring altitude. Transmitting power and receiver gain are also controlled to have the dynamic range of the received power be reduced. In addition, low measurement errors are obtained by improving the sweep linearity using the Direct Digital Synthesizer(DDS) and minimizing the phase noise employing the reference clock(Ref_CLK) as the offset frequency of the Phase Locked Loop(PLL).
Comparison of SE Evaluation Methods for HEMP Shelters
Chung, Yeon-Choon ; Lee, Jongkyung ; Kwun, Suk-Tai ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 25, issue 11, 2014, Pages 1197~1200
DOI : 10.5515/KJKIEES.2014.25.11.1197
Two test standards to be applied for evaluating shielding effectiveness of HEMP protection facilities, MIL-STD-188-125-1 and IEEE std. 299, provide different test results in spite of the same facility. In particular, at the frequency range of 10 kHz~20 MHz, it is confirmed that the test results by the IEEE Std. 299 are about 20~30 dB lower than the evaluated results by MIL-STD-188-125-1. These results are due to the different measurement conditions specified in the two test standards. Therefore, IEEE Std. 299 can be applied for the shortening of test distance, but the required SE performance based on MIL-STD-188-125-1 must be modified.