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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 23, Issue 12 - Dec 2012
Volume 23, Issue 11 - Nov 2012
Volume 23, Issue 10 - Oct 2012
Volume 23, Issue 9 - Sep 2012
Volume 23, Issue 8 - Aug 2012
Volume 23, Issue 7 - Jul 2012
Volume 23, Issue 6 - Jun 2012
Volume 23, Issue 5 - May 2012
Volume 23, Issue 4 - Apr 2012
Volume 23, Issue 3 - Mar 2012
Volume 23, Issue 2 - Feb 2012
Volume 23, Issue 1 - Jan 2012
Selecting the target year
Dual-Fed Small Repeater Antenna with High Isolation
Seong, Cheol-Min ; Jang, Jae-Su ; Ha, Jae-Kwon ; Park, Dong-Chul ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 23, issue 6, 2012, Pages 661~668
DOI : 10.5515/KJKIEES.2012.23.6.661
In this paper, a dual-fed small ICS repeater antenna with high isolation is designed, fabricated, and measured. Bandwidth and gain are optimized by changing the stub lengths near main patch and power divider, and also by changing the size of parasitic patch. To improve the isolation characteristic of the antenna, a dual-feeding method is applied in designing the antenna. The fabricated antenna has a VSWR less than 2, a gain over 7 dBi, and an isolation between the donor and the server antennas less than -65 dB from 1,920~2,170 MHz for 3G mobile communication.
Novel Mutual Inductance Formula for the Magnetic Resonance Wireless Power Transmission System Using Helical Coils
Jang, Ju-Yeop ; Hur, Jung ; Kim, Yong-Nam ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 23, issue 6, 2012, Pages 669~681
DOI : 10.5515/KJKIEES.2012.23.6.669
In this paper, analytical calculations using a novel mutual inductance formula for a resonant wireless power transmission system using helical coils. The look-up table of critical variables during the mutual inductance calculation process was formulated. The calculation results for resonant frequency and insertion loss were compared with experimental results when the distance between the two helical coils in a structure where the transmission and reception is symmetrical was varied with 10 mm increments from 53 mm to 500 mm. On average, the resonant frequency showed a difference of 5.63 % between the experimental results and the calculation results. The insertion loss had an average difference 2.25 dB where the smallest difference of 0.33 dB occurred with 290 mm. It was found that the experimental results without using a balun were in greater agreement with the calculation results.
A Highly Linear Self Oscillating Mixer Using Second Harmonic Injection
Kim, Min-Hoe ; Cho, Choon-Sik ; Lee, Jae-Wook ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 23, issue 6, 2012, Pages 682~690
DOI : 10.5515/KJKIEES.2012.23.6.682
In this paper, a highly linear self oscillating mixers(SOM) using second harmonic injections are presented. The H-slot defected ground structure(DGS) is designed as a balanced resonator for oscillation in the proposed SOM. Since the H-slot DGS resonator achieves a high Q factor, it is a suitable structure to provide low phase noise for the oscillator. The single balanced mixer is utilized in this work and it provides good LO-RF isolation since balanced LO signals are suppressed at the RF input port. In order to inject the second harmonic of the IF, we propose two different methods using feedback loops. In the first method, IF achieves a 3.08 dB conversion gain at 226 MHz with input power of -20 dBm at 5 GHz RF input signal. The IF achieves 2 dB conversion gain at 423 MHz with the input power of -20 dBm at 5.2 GHz RF input signal in the second method. The measured IMD3s are 61.8 dB and 65 dB for the each method. These SOMs present improved linearity compared to that without the second harmonic injection because IMD3s are improved by 18. dB and 21 dB for each method.
Design of a Low Phase Noise Vt-DRO Based on Improvement of Dielectric Resonator Coupling Structure
Son, Beom-Ik ; Jeong, Hae-Chang ; Lee, Seok-Jeong ; Yeom, Kyung-Whan ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 23, issue 6, 2012, Pages 691~699
DOI : 10.5515/KJKIEES.2012.23.6.691
In this paper, we present a Vt-DRO with a low phase noise, which is achieved by improving the coupling structure between the dielectric resonator and microstrip line. The Vt-DRO is a closed-loop type and is composed of 3 blocks; dielectric resonator, phase shifter, and amplifier. We propose a mathematical estimation method of phase noise, using the group delay of the resonator. By modifying the coupling structure between the dielectric resonator and microstrip line, we achieved a group delay of 53 nsec. For convenience of measurement, wafer probes were inserted at each stage to measure the S-parameters of each block. The measured S-parameter of the Vt-DRO satisfies the open-loop oscillation condition. The Vt-DRO was implemented by connecting the input and output of the designed open-loop to form a closed-loop. As a result, the phase noise of the Vt-DRO was measured as -132.7 dBc/Hz(@ 100 kHz offset frequency), which approximates the predicted result at the center frequency of 5.3 GHz. The tuning-range of the Vt-DRO is about 5 MHz for tuning voltage of 0~10 V and the power is 4.5 dBm. PFTN-FOM is -31 dBm.
Linear Detection Method Based on Semi-Definite Relaxation of 16-QAM in MIMO Systems
Lee, Ki-Jun ; Byun, Youn-Shik ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 23, issue 6, 2012, Pages 700~705
DOI : 10.5515/KJKIEES.2012.23.6.700
This paper suggests the detecting method in which it uses the candidate symbol obtained through PI-SDR, the little computational complexity is required. By using the candidate symbol matrices obtained through PI-SDR, ZF and MMSE method was applied and the received signal was detected. The linear detecting method using PI-SDR candidate symbol is out of the performance than ML detecting method but the complexity is low. Because of using the symbol come close to the solution of ML, the proposed method's performance is better than the existing ZF and MMSE method.
Performance and Jitter Effects Analysis of Single Bit Electro-Optical Sigma-Delta Modulators
Nam, Chang-Ho ; Ra, Sung-Woong ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 23, issue 6, 2012, Pages 706~715
DOI : 10.5515/KJKIEES.2012.23.6.706
Electro-optical sigma-delta modulators are the core module of digital receiver to digitize wideband radio-frequency signals directly at an antenna. Electro-optical sigma-delta modulators use a pulsed laser to oversample an input radio-frequency signals at two Mach-Zehnder Interferometer(MZI) and shape the quantization noise using a fiber-lattice accumulator. Decimation filtering is applied to the quantizer output to construct the input signal with high resolution. The jitter affects greatly on reconstructing the original input signal of modulator. This paper analyzes the performance of first order single bit electro-optical sigma-delta modulator in the time domain and the frequency domain. The performance of modulator is analyzed by using asynchronous spectral averaging of the reconstructed signal's spectrum in the frequency domain. The reference value of time jitter is presented by analyzing the performance of jitter effects. This kind of jitter value can be used as a reference value on the design of modulators.
Reduction of Electromagnetic Interference between the LCD Driving Module and WWAN Antennas
Kim, In-Bok ; Park, Jin-Hyun ; Kang, Il-Heung ; Kim, Hong-Joon ; Woo, Dong-Sik ; Kim, Kang-Wook ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 23, issue 6, 2012, Pages 716~722
DOI : 10.5515/KJKIEES.2012.23.6.716
In this paper, we analyzed the RF interactions between WWAN antennas and an LCD driving module inside the cover of a notebook computer, and discussed reduction method of RF coupling. In order to simulate the RF noise source from the LCD driving module, a multi-band antenna was designed and used with a simplified notebook model to test the RF coupling phenomena. We verified that the RF noise coupling is enhanced at certain frequencies due to cavity structure formed inside the notebook computer. Also, we showed that conductive barrier walls, which are inserted inside the notebook, could be effective in reducing RF coupling.
Analysis for the RCS of a Trihedral Corner Reflector with Consideration of the Effect of Front Surface
Shin, Jong-Chul ; Kweon, Soon-Koo ; Oh, Yi-Sok ; Kim, Se-Young ; Jeon, Byeong-Tae ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 23, issue 6, 2012, Pages 723~730
DOI : 10.5515/KJKIEES.2012.23.6.723
The radar cross section(RCS) of a trihedral corner reflector(TCR) should be accurately computed when it is used as an external calibration target for a satellite synthetic aperture radar(SAR) calibration campaign. This paper presents the RCS analysis on a trihedral corner reflector which is installed on a calibration site, using the wave reflection from the rough surface and the wave diffraction from the TCR edges. The results in this paper show quantitatively the effect of the front surface on the RCS of a TCR. The difference of the RCS between a TCR in air and a TCR on a ground surface is computed by including the interaction term which consists of the edge diffraction from the TCR edges and the surface reflection from the front rough surface. The reflection coefficient of a randomly rough surface is a function of the surface roughness and dielectric constant of the surface. The RCS of
size TCR on a ground is 0.46 dB higher than TCR in air at 9.65 GHz, and this can reach at maximum 1.55 dB depending on a surface condition and TCR size. The effect of the front surface on the RCS of a TCR increases, as the surface roughness decreases, the soil moisture increases, and the size of TCR in wavelength decreases.
An Investigation of Higher Order Modes in Widthwise in Parallel Plate Waveguide
Cho, Gyu-Yeong ; Jo, Hyun-Dong ; Park, Wee-Sang ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 23, issue 6, 2012, Pages 731~739
DOI : 10.5515/KJKIEES.2012.23.6.731
Transverse electric modes in parallel plate waveguide of which cut-off frequency is much lower than that of
mode generally known as the lowest higher order mode are investigated. Electric and magnetic field components of the modes are evaluated with the assumption that boundaries at both sides are perfect magnetic conductor. The existence of these modes are verified by simulation and experimental measurement of parallel plate waveguide cavity. Changed characteristics from the fact that the boundaries are imperfect are studied.
A Study on Beam Operation of an Airborne AESA Radar with Uniform Search Performance in Whole Scan Area
Ahn, Chang-Soo ; Roh, Ji-Eun ; Kim, Seon-Joo ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 23, issue 6, 2012, Pages 740~747
DOI : 10.5515/KJKIEES.2012.23.6.740
An Active Electronically Scanned Array(AESA) radar required necessarily as the Fire Control Radar(FCR) of recent fighters has ununiform detection range with regard to scan angle due to scan loss. Although the compensation method of scan loss in an AESA radar with variable dwell time is investigated, the effectiveness of the method in a fighter FCR with multi-function such as search, track, and missile guidance within limited resources should be considered systematically. In this paper, uniform search performance of an AESA radar using variable dwell time with regard to scan angle is derived. We assumed the search load of 50 % for case without changing dwell time in fixed frame time and showed the fighter FCR requirement for multi-function is not satisfied because the search load for the uniform search performance should be increased by about 100 %. On the other hand, in case of increasing the frame time for the uniform search performance and search load of 50 %, degradation of the search performance is shown by 86.7 % compared with the former. Based on these analyses, the effective beam operation strategy on an airborne AESA radar with uniform search performance in whole scan area is described with consideration of frame time, search load and performance as a whole.
Linear Region Extension of MR Curve in ML Based Monopulse
Kim, Heung-Su ; Lim, Jong-Hwan ; Yang, Hoon-Gee ; Chung, Young-Seek ; Kim, Doo-Soo ; Lee, Hee-Young ; Kim, Seon-Joo ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 23, issue 6, 2012, Pages 748~751
DOI : 10.5515/KJKIEES.2012.23.6.748
The performance of a monopulse estimator is depend on its monopulse ratio(MR) curve. To improve its performance, a mathematical expression of the MR curve that is associated with an array the parameters is needed. In this paper, we present a novel monopulse estimator that uses the inverse function of a MR curve for the Maximum Likelihood (ML)-based monopulse estimator. It is shown that the proposed method can extend the linear region of the MR curve, which in turn improve the estimation accuracy. Moreover, it's performance is compared with the ML-based method through simulation.
Design and Fabrication of a Rectangular Spiral Type Antenna for 433 MHz
Oh, Sung-Kon ; An, Jun-O ; Kim, Boo-Gyoun ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 23, issue 6, 2012, Pages 752~755
DOI : 10.5515/KJKIEES.2012.23.6.752
In this paper, the rectangular spiral shaped antenna is designed and fabricated for 433 MHz TPMS. Proposed antenna has the -10 dB impedance bandwidth of 23 MHz(427~450 MHz). The antenna is fabricated with the size of
by brass material. Return loss is below -10 dB at 433 MHz
10 MHz mounted tire wheel and not mounted both. The radiation power is -44.21 dBm without wheel and -50.0 dBm installed wheel. The proposed antenna can be practical use through data transmission test results.
Multibeam Reflector Antenna for Ka-Band Communication Satellite
Yun, So-Hyeun ; Uhm, Man-Seok ; Choi, Jang-Sup ; Yom, In-Bok ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 23, issue 6, 2012, Pages 756~759
DOI : 10.5515/KJKIEES.2012.23.6.756
This paper presents the multibeam service coverage of GEO(Geostationary Orbit) satellite and the practical antenna scheme scenarios to provide the universal communication services on the Korean peninsula. The proposed antenna systems consist of the simplest scheme and feed network so that they can be mounted on satellites. The feed networks are effectively organized according to the frequency and polarization plan. Despite simple structure, all scenarios meet the electrical performance by the optimization of feed allocation and feed excitation.