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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 26, Issue 12 - Dec 2015
Volume 26, Issue 11 - Nov 2015
Volume 26, Issue 10 - Oct 2015
Volume 26, Issue 9 - Sep 2015
Volume 26, Issue 8 - Aug 2015
Volume 26, Issue 7 - Jul 2015
Volume 26, Issue 6 - Jun 2015
Volume 26, Issue 5 - May 2015
Volume 26, Issue 4 - Apr 2015
Volume 26, Issue 3 - Mar 2015
Volume 26, Issue 2 - Feb 2015
Volume 26, Issue 1 - Jan 2015
Selecting the target year
NIC-Based Non-Foster Impedance Matching of a Resistively Loaded Vee Dipole Antenna
Yang, Hyemin ; Kim, Kangwook ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 26, issue 7, 2015, Pages 597~605
DOI : 10.5515/KJKIEES.2015.26.7.597
Negative impedance converter(NIC)-based non-Foster impedance matching is proposed for an electrically small antenna. The antenna considered in this work is a resistively loaded vee dipole(RVD) antenna, which has considerable reflection at the feed point because of its large negative input reactance. The non-Foster matching circuit built near the feed point consists of two-stage NIC circuit and a capacitor connected between the stages. The NIC is realized by using operational amplifiers(op-amps) and resistors. The circuit is designed by considering of the input impedance according to the finite open-loop gain of the practical NICs. The stability test of the impedance-matched RVD antenna is performed. The non- Foster matching circuit is implemented with the RVD antenna. The measured impedance demonstrates that the proposed non-Foster matching circuit effectively reduces the input reactance of the RVD antenna.
Dual-Band Orthogonal-Polarization Microstrip Antenna for Vehicle-to-Nomadic Devices Communication
Lim, Eunsook ; Lee, Dong-Hyo ; Pyo, Seongmin ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 26, issue 7, 2015, Pages 606~612
DOI : 10.5515/KJKIEES.2015.26.7.606
This paper proposes a new design of a dual-band orthogonal-polarization microstrip antenna for V2N(Vehicle to Nomadic Device) communication system. The proposed antenna consists of a perpendicular feeding structure for utilizing orthogonal linear polarizations and an microstrip radiator which loaded by close-looped H-shape slot for obtaining dual-band operation. Due to the geometrically different loading effect of the close-looped H-shape slot for each feeding location, the orthogonally linear polarization at dual-band operation of the proposed antenna can be successfully achieved. The proposed antenna theoretically and experimentally demonstrates the vertical linear polarization at the operating frequency of 1.8 GHz and the horizontal linear polarization at the operating frequency of 2.4 GHz, respectively. The simulation and measurement results of the implemented antenna have been in good agreement with the reflection coefficients, radiation patterns, and realized antenna gains.
Paper-Based Pattern Switchable Antenna Using Inkjet-Printing Technology
Eom, Seung Hyun ; Lim, Sungjoon ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 26, issue 7, 2015, Pages 613~619
DOI : 10.5515/KJKIEES.2015.26.7.613
In this paper, we proposed a paper-based pattern-switchable antenna using inkjet-printing technology. The proposed antenna is composed of two bow-tie antennas and a switching network. The bow-tie antennas are inkjet-printed on paper using a low cost home printer. The switching network is built on a printed-circuit-board(PCB) and consists of a single-pole-double-throw(SPDT) switch and balun element. A double-sided parallel-strip line(DSPSL) can convert the unbalanced microstrip mode to the balanced strip mode. Two bow-tie antennas have different radiation patterns because of the different orientation of the reflectors. It is demonstrated from EM simulation and measurement that the radiation patterns of the proposed antenna are successfully switched by the SPDT.
2~6 GHz Wideband GaN HEMT Power Amplifier MMIC Using a Modified All-Pass Filter
Lee, Sang-Kyung ; Kim, Dong-Wook ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 26, issue 7, 2015, Pages 620~626
DOI : 10.5515/KJKIEES.2015.26.7.620
In this paper, a 2~6 GHz wideband GaN power amplifier MMIC is designed and fabricated using a second-order all-pass filter for input impedance matching and an LC parallel resonant circuit for minimizing an output reactance component of the transistor. The second-order all-pass filter used for wideband lossy matching is modified in an asymmetric configuration to compensate the effect of channel resistance of the GaN transistor. The power amplifier MMIC chip that is fabricated using a
GaN HEMT foundry process of Win Semiconductors, Corp. is
and shows a flat linear gain of about 13 dB and input return loss of larger than 10 dB. Under a saturated power mode, it also shows output power of 38.6~39.8 dBm and a power-added efficiency of 31.3~43.4 % in 2 to 6 GHz.
A Novel Dual-Layer Differential Equal Gain Transmission Technique Using M-PSK Constellations
Kim, Young-Ju ; Seo, Chang-Won ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 26, issue 7, 2015, Pages 627~635
DOI : 10.5515/KJKIEES.2015.26.7.627
We propose a dual-layer differential equal-gain codebook design methodology for LTE-Advanced(LTE-A), IEEE802.ac, and radar system having multiple transmit and receive antennas, and make computer simulations to evaluate its link-level performaces. M-ary phase shift keying constellation is used as its codeword elements to utilize low-cost power amplifiers at mobile stations. Especially, the proposed codebook can meet radar systems requirement for the high-powered equal-gain transmission property. Due to the temporal correlation of the adjacent channel, the proposed differential codebook can quantize only the differential information of the channel instead of the whole channel subspace, which virtually increase the codebook size to realize more accurate quantization of the channel. The proposed codebook has the same properties of LTE codebook that is, constant modulus, complexity reduction, and nested property. Computer simulations show that the proposed codebook performs better than the conventional 8-ary codebooks with the same amount of feedback information.
EMI Problem and Solutions of Unusual Harmonics in Low-Speed PCB
Kim, Chan-Su ; Lee, Hai-Young ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 26, issue 7, 2015, Pages 636~645
DOI : 10.5515/KJKIEES.2015.26.7.636
In this paper, unusual harmonics noise problem of digital electronic products in mass production was introduced and a practical solution was proposed. Generally, 5th or higher harmonics noise level has been ignored in circuit designs because over 5th harmonics noise decreases by 40 (dB/decade). Through some measurements, it is confirmed that over 10th harmonics noise can propagate and radiate in case of a certain PCB or housing conditions. We propose a capacitively loaded micro-strip low pass filter for commercial products having spatial design constraints and measured the effectiveness. The proposed structure can solve both of the continual increment of harmonics noise level and the spatial design constraint of commercial products. We expect the proposed method be effectively used for various digital electronic products.
Evaluating the Perception of Distance to High-Voltage Power Lines from Home Using Transmission and Substation Geographic Information System
Ock, Minsu ; Lee, Moo-Song ; Jeon, Bomin ; Kim, Hwa Jung ; Ryu, Hyun Mi ; Myung, Sung-Ho ; Min, Suk Won ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 26, issue 7, 2015, Pages 646~655
DOI : 10.5515/KJKIEES.2015.26.7.646
The purpose of this study was to evaluate the perceived distance from home to high-voltage power lines using a transmission and substation geographic information system(TGIS). Of the 725, 136 respondents reported that high voltage power transmission tower, power lines or substation was within visual field range from home. Among them, 114 respondents reported valid address, which could be used in the analysis of TGIS. Forty two respondents(36.8 %) estimated that the power lines were closer and 15 respondents(13.2 %) estimated that they were farther than they actually were. Our current findings suggest that the reported distance from home to high-voltage power transmission towers, power lines, and substations cannot be used as a proxy for exposure to electromagnetic fields due to the low validity.
Bistatic ISAR Imaging with UWB Radar Employing Motion Compensation for Time-Frequency Transform
Jang, Moon-Kwang ; Cho, Choon-Sik ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 26, issue 7, 2015, Pages 656~665
DOI : 10.5515/KJKIEES.2015.26.7.656
In this paper, we improved the clarity and quality of the radar imaging by applying motion compensation for time-frequency transform in B-ISAR imaging. The proposed motion compensation algorithm using UWB radar is verified. B-ISAR algorithm procedure and time-frequency transform for improved motion compensation are provided for theoretical ground. The image was created by a UWB Radar B-ISAR imaging algorithm method. Also, creating a B-ISAR imaging algorithm for motion compensation of time-frequency transformation method was used. The B-ISAR Imaging algorithm is implemented using STFT(Short-Time Fourier Transform), GWT(Gabor Wavelet Transform), and WVD(Wigner-Ville Distribution) approaches. The performance of STFT is compared with the GWT and WVD algorithms. It is found that the WVD image shows more clarity and decreased spread phenomenon than other methods.
Angle Estimation of Two Targets in the Same Antenna Beam Using Adaptive Phase-Comparison Monopulse Technique
Lee, Seong-Hyeon ; Lee, Seung-Jae ; Choi, Gak-Gyu ; Yi, Jae-Woong ; Kim, Kyung-Tae ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 26, issue 7, 2015, Pages 666~674
DOI : 10.5515/KJKIEES.2015.26.7.666
In this paper, we introduce an adaptive phase-comparison monopulse technique for angle estimation of two targets in the same antenna beam. The proposed method determines a more suitable technique(between conventional phase comparison monopulse technique and Zheng`s method) based on interference between two targets in Fourier domain. Consequently, regardless of the interference, angles of each individual target can be accurately estimated by means of the proposed method. In simulations, we assumed that two point targets with same velocity are located in the same antenna beam, and the accuracy improvement of the proposed method is verified by using several simulations.
Design and Implementation of Multi-Function Conversion Block for Microwave Receiver
Kim, Jae-Hyun ; Go, Min-Ho ; Park, Hyo-Dal ;
The Journal of Korean Institute of Electromagnetic Engineering and Science, volume 26, issue 7, 2015, Pages 675~678
DOI : 10.5515/KJKIEES.2015.26.7.675
In this paper, we proposed a multi-function conversion block for microwave receiver. The proposed multi-function conversion block is composed of a broadband voltage controlled oscillator and a dual-mode mixer. Depending on whether the bias voltage is supplied, the first IF(Intermediate Frequency) output frequency(4,595 MHz/6,045 MHz) needed in microwave receiver is converted to 720 MHz and the another IF output frequency(720 MHz) for receiving Ku-band has the multi-functional operations of the dual mode that are bypass and attenuation without frequency conversion. Implementation and measurement results show that each intermediate frequency has conversion loss characteristic according to the LO power. The LO power conversion loss of 4,595 MHz at the LO levels from 2 dBm to 4 dBm is 13 dB, another of 6,035 MHz is 12 dB and the other of 720 MHz is 7.0 dB.