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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 19, Issue 12 - Dec 2008
Volume 19, Issue 11 - Nov 2008
Volume 19, Issue 10 - Oct 2008
Volume 19, Issue 9 - Sep 2008
Volume 19, Issue 8 - Aug 2008
Volume 19, Issue 7 - Jul 2008
Volume 19, Issue 6 - Jun 2008
Volume 19, Issue 5 - May 2008
Volume 19, Issue 4 - Apr 2008
Volume 19, Issue 3 - Mar 2008
Volume 19, Issue 2 - Feb 2008
Volume 19, Issue 1 - Jan 2008
Selecting the target year
Miniaturized Conically Stepped COBRA for High Power Electromagnetic Generator
Ahn, Ji-Hwan ; Lee, Sang-Heun ; Yoon, Young-Joong ; Kim, Jun-Yeon ; Lee, Woo-Sang ; So, Joon-Ho ; Han, In-Hee ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 19, issue 9, 2008, Pages 947~956
DOI : 10.5515/KJKIEES.2008.19.9.947
In this paper, miniaturized conically stepped COBRA is proposed. In order to prevent electrical breakdown, COBRA, which consists of hem and lens, has to get bigger if it is designed with conventional method. Because of the phase error increase, shortening the length of the antenna without changing the aperture size leads to the reduction of the antenna gain. To avoid this, the phase error at the aperture is compensated by transforming the COBRA lens into conically stepped form. The simulations result shows that the proposed antenna has higher gain than the conventional COBRA in spite of the size reduction from 1,300 mm to 600 mm. The fabricated and measured COBRA has the gain of 26.2 dBi.
Research on the Accuracy of Prediction of Radiation Emission from PCB within an Enclosure with a Rectangular Aperture
Park, Yong-Bae ; Jung, Ki-Bum ; Chung, Yeon-Choon ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 19, issue 9, 2008, Pages 957~967
DOI : 10.5515/KJKIEES.2008.19.9.957
In this paper, we propose the prediction algorithm of radiation emission from the PCB in an enclosure with a rectangular aperture. PCB scanner is used to measure the near field, which is substituted with an equivalent electric dipole source. Green function and Fourier transform are utilized to represent the electromagnetic fields within and outside the enclosure, respectively. The radiation emission is estimated by using the mode matching technique and surface equivalent theorem. The theoretical results are compared with the measurement to check the accuracy of our analysis.
Analysis of TE-Wave Scattering from Transversal-Shifted Tandem Slits Using Wiener-Hopf Techniques and Fourier Transform Analysis
Seo, Tae-Yoon ; Ahn, Sung-Hwan ; Lee, Jae-Wook ; Cho, Choon-Sik ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 19, issue 9, 2008, Pages 968~977
DOI : 10.5515/KJKIEES.2008.19.9.968
In this paper, an analysis of TE-wave scattering from transversal-shifted tandem slits using fourier transform analysis and Wiener-Hopf technique are derived and the electrical performances have been compared with a commercially availabel software. In Fourier transform analysis, it is shown that a fast-convergent series solution can be obtained when the distance between the slits is very narrow, while in Wiener-Hopf technique, it is found that the highly-accurate approximation can be obtained when the gap between the slits becomes wider. In addition, this paper has dealt with a good agreement between two analytical solutions.
Design of RFID Metal Tag Antenna with a Minimum Effect according to Attached Metal Surface Size
HwangBo, Chang ; Seo, Seung-Up ; Lee, Yun-Bok ; Yang, Myo-Geun ; Seong, Won-Mo ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 19, issue 9, 2008, Pages 978~984
DOI : 10.5515/KJKIEES.2008.19.9.978
In this paper, we propose a RFID metal tag antenna with a minimum by size of a metal surface to attach. This proposed tag antenna is a patch antenna which is able to stick on metal surface and designed for very slim structure (
mm) antenna that is matched to a chip impedance. This has a loop coupling feeding and consists of a inner radiator and a outer radiator. The outer radiator activates the current to concentrate on the inner radiator regardless of metal size to attach. Also the tag antenna is designed by CST microwave tool and the performance is measured in the anechoic chamber. The optimum antenna has 3.77 % of the matching bandwidth(
dB). The readable range of the tag antenna is about 2.9 m on metal(max. size
mm) and 5.5 m in free space according to the measurement results.
Balanced Mixer Based on Composite Right/Left-Handed Transmission Line Leaky-Wave Antenna
Kim, Young ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 19, issue 9, 2008, Pages 985~991
DOI : 10.5515/KJKIEES.2008.19.9.985
This paper presents a novel balanced mixer receiver front-end design based on a metamaterial structure applicable to differential-/common-mode excitation. This metamaterial structure functions as a leaky-wave antenna and provides in-trinsic common-mode suppression. Low LO leakage and high RF to LO isolation are achieved without additional filters for LO and RF paths. The metamaterial is based on a unit-cell which under a differential-mode excitation behaves like a composite right/left-handed(CRLH) metamaterial. In contrast, the metamaterial unit-cell is below cut-off under a common-mode excitation. Experimental results are used to verify the proposed metamaterial's differential-/common-mode characteristics. The metamaterial is integrated with a balanced mixer design resulting in an operation frequency range of
GHz with an optimum mixer conversion loss of 21.1 dB at 2,4 GHz.
Design of VHF-Band Wideband High-Power Switch
Lee, Byeong-Nam ; Park, Dong-Chul ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 19, issue 9, 2008, Pages 992~999
DOI : 10.5515/KJKIEES.2008.19.9.992
This paper describes the design of SPST PIN diode switch which has a 2 kW high power handling capability within
switching speed in
MHz VHF-band. Design factors were investigated and it was confirmed by simulation that the characteristics of insertion loss, VSWR, and isolation met design goal. Also, the capability to handle 2 kW high power with maximum fast switching speed less than
was confirmed and insertion loss less than 0.2 dB, VSWR less than 1.17:1, and isolation higher than 40 dB were obtained by experiments.
A Performance Evaluation of MB-OFDM UWB System Considering the Domestic DAA Regulation
Shin, Cheol-Ho ; Choi, Sang-Sung ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 19, issue 9, 2008, Pages 1000~1009
DOI : 10.5515/KJKIEES.2008.19.9.1000
The purpose of this paper is to analyze the performance of MB-OFDM UWB system when the interference signal that can be WIMAX signal or 4 G system signal is received by detection limit of -80 dBm/MHz proposed in Korea for DAA(Detect And Avoid) to permit UWB in
GHz. MB-OFDM UWB system supports two transmission modes; one is TFI(Time frequency Interleaving) mode that transmits OFDM symbols using different carrier frequency from symbol to symbol according to Time Frequency(TF) codes, the other is FFI(Fixed Frequency Interleaving) mode that transmits OFDM symbols using a specific carrier frequency. In this paper, we considered the TX average power and the synchronization structure to reflect the effect of frequency hopping according to TFC. Interference analysis results show that the WiMAX system is fenced thoroughly from UWB interference in domestic DAA regulation, but the performance of MB-OFDM UWB system is degraded seriously by an interference signal with the DAA detection limit even in frequency Hopping mode that can get frequency diversity effect.
Noise Analysis and Measurement for a CW Bio-Radar System for Non-Contact Measurement of Heart and Respiration Rate
Jang, Byung-Jun ; Yook, Jong-Gwan ; Na, Won ; Lee, Moon-Que ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 19, issue 9, 2008, Pages 1010~1019
DOI : 10.5515/KJKIEES.2008.19.9.1010
In this paper, we present a noise analysis and measurement results of a bio-radar system that can detect human heartbeat and respiration signals. The noise analysis including various phase noise effects is very important in designing the bio-radar system, since the frequency difference between the received signal and local oscillator is very small and the received power is very low. All of the noise components in a bio-radar system are considered from the point of view of SNR. From this analysis, it can be concluded that the phase noise due to antenna leakage is a dominant factor and is a function of range correlation. Therefore, the phase noise component with range correlation effect, which is the most important noise contribution, is measured using the measurement setup and compared with the calculated results. From the measurement results, our measurement setup can measure a closed-in phase noise of a free-running oscillator. Based on these results, it is possible to design a 2.4 GHz bio-radar system quantitatively which has a detection range of 50 cm and low power of 1 mW without additional PLL circuits.
A Study on Critical Angle of Metamaterial with Drude Model
Lee, Kyung-Won ; Hong, Ic-Pyo ; Chung, Yeong-Chul ; Yook, Jong-Gwan ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 19, issue 9, 2008, Pages 1020~1027
DOI : 10.5515/KJKIEES.2008.19.9.1020
In this paper, the refraction angles and the critical angles of metamaterials which is assumed by the Drude model are analytically studied. To analyze the electromagnetic reflection and the transmission properties of metamaterial slab, we used "-1" for the permeability and the permittivity at 30 GHz in Drude model for metamaterials in this paper, respectively. Due to the variation of signes of material constants for frequency ranges in Drude model, the derived refraction angle and the critical angles for each frequency ranges are differently observed. The results in this paper show that the properties the refraction angles and the critical angles for the broadband in metamaterials can be used to understand the electromagnetic properties of metamaterials and microwave applications.
Compensation of OFDM Signal Degraded by Phase Noise and IQ Imbalance
Ryu, Sang-Burm ; Kim, Sang-Kyun ; Ryu, Heung-Gyoon ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 19, issue 9, 2008, Pages 1028~1036
DOI : 10.5515/KJKIEES.2008.19.9.1028
In the OFDM system, IQ imbalance problem happens at the RF front-end of transceiver, which degrades the BER(bit error rate) performance because it affects the constellation in the received signal. Also, phase noise is generated in the local oscillator of transceivers and it destroys the orthogonality between the subcarriers. Conventional PNS algorithm is effective for phase noise suppression, but it is not useful anymore when there are jointly IQ(In-phase and Quadrature) imbalance and phase noise. Therefore, in this paper, we analyze the effect of IQ imbalance and phase noise generated in the down-conversion of the receiver. Then, we estimate and compensate the IQ imbalance and phase noise at the same time. Compared with the conventional method that IQ imbalance after IFFT is estimated and compensated in front of FFT via the feedback, this proposed method extracts and compensates effect of IQ imbalance after FFT stage. In case IQ imbalance and phase noise exist at the same time, we can decrease complexity because it is needless to use elimination of IQ imbalance in time domain and training sequences and preambles. Also, this method shows that it reduces the ICI and CPE component using adaptive forgetting factor of MMSE after FFT.
Increment of Antenna Efficiency of the Mobile Phone Antenna by EMI Slot
Son, Tae-Ho ; Hong, Min-Gi ; Lee, Jae-Ho ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 19, issue 9, 2008, Pages 1037~1044
DOI : 10.5515/KJKIEES.2008.19.9.1037
Radiation efficiency and antenna gain, in this paper, can be increased by the slot on EMI shield painted on the mobile phone back cover. When the EMI slot which has proper dimension and location is located on the EMI paining area in the phone, the increment of antenna current density due to mutual coupling between the antenna and slot derives increment of antenna efficiency. For the verification of EMI slot effect, we apply the EMI slot to the mobile phone which is operating on GSM/DCS/USPCS/WCDMA quad band, and measure
and antenna efficiency. It's shown that resonant frequency is not changed and radiation efficiencies to frequency channels by EMI slot are increased from 0.21 % to 8.96 %.
A Design of Non-Coherent CMOS IR-UWB Receiver
Ha, Min-Cheol ; Park, Young-Jin ; Eo, Yun-Seong ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 19, issue 9, 2008, Pages 1045~1050
DOI : 10.5515/KJKIEES.2008.19.9.1045
In this paper presents a CMOS RF receiver for IR-UWB wireless communications is presented. The impulse radio based UWB receiver adopts the non-coherent demodulation that simplifies the receiver architecture and reduces power consumption. The IR-UWB receiver consists of LNA, envelop detector, VGA, and comparator and the receiver including envelope detector, VGA, and comparator is fabricated on a single chip using
CMOS technology. The measured sensitivity of IR-UWB receiver is down to -70 dBm and the BER
, respectively at data rate 1 Mbps. The current consumption of IR-UWB receiver except external LNA is 5 mA at 1.8 V.
Analysis of Properties of Flake Sendust EM Wave Absorber according to Granularity
Park, Soo-Hoon ; Kim, Dong-Il ; Choi, Dong-Han ; Kim, Seong-Yeon ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 19, issue 9, 2008, Pages 1051~1057
DOI : 10.5515/KJKIEES.2008.19.9.1051
In this paper, we analyzed the characteristics of the EM wave absorber which was fabricated by using flake sendust (soft metal magnetic powder). The flake sendust was made of 3 different granularity by attrition mill. First, we have fabricated 3 kind of EM wave absorbers using the flake sendust and CPE(Chlorinated Polyethylene) and measured the S-parameters of the EM wave absorber. The complex relative permittivity and permeability were calculated from the measured data and the variations according to a change of granularity were researched. As a result, it was confirmed that the EM wave absorber using flake sendust with the
average granularity has outstanding absorption ability in high frequency range(C band) for the reduction of eddy current loss(increase of permeability) and the increase of space charge polarization(increase of permittivity).
A Study on Adaptive Interference Cancellation System of RF Repeater Using the Grouped Constant-Modulus Algorithm
Han, Yong-Sik ; Yang, Woon-Geun ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 19, issue 9, 2008, Pages 1058~1064
DOI : 10.5515/KJKIEES.2008.19.9.1058
In this paper, we proposed a new hybrid interference canceller using the adaptive filter with Grouped CMA(Constant Modulus Algorithm)-LMS(Least Mean Square) algorithm in the RF(Radio Frequency) repeater. The feedback signal generated from transmitter antenna to receiver antenna reduces the performance of the receiver system. The proposed interference canceller has better channel adaptive performance and a lower MSE(Mean Square Error) than conventional structure because it uses the cancellation method of Grouped CMA algorithm. This structure reduces the number of iterations fur the same MSE performance and hardware complexity compared to conventional nonlinear interference canceller. Namely, MSE values of the proposed algorithm were lower than those of LMS algorithm by 2.5 dB and 4 dB according to step sizes. And the proposed algorithm showed fast speed of convergence and similar MSE performance compared to VSS(Variable Step Size)-LMS algorithm.