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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
> Journal Vol & Issue
Journal of electromagnetic engineering and science
Journal Basic Information
Journal DOI :
The Korean Institute of Electromagnetic Engineering and Science
Editor in Chief :
Volume & Issues
Volume 15, Issue 4 - Oct 2015
Volume 15, Issue 3 - Jul 2015
Volume 15, Issue 2 - Apr 2015
Volume 15, Issue 1 - Jan 2015
Selecting the target year
Review of the Hidden Rays of Diffraction
Kim, Se-Yun ;
Journal of electromagnetic engineering and science, volume 15, issue 1, 2015, Pages 1~5
DOI : 10.5515/JKIEES.2015.15.1.1
A high-frequency analysis technique, called the hidden rays of diffraction (HRD), is reviewed in this paper. The physical optics and the rigorous diffraction coefficients of a perfectly conducting wedge illuminated by a plane wave are compared. The physical existence of hidden rays on the shadow boundary is explained in view of the geometric theory of diffraction (GTD). In particular, a systematic tracing of hidden rays and its visualization are precisely described by introducing the concept of the supplementary boundary. The physical meaning of the null-field condition in the complementary region is also explained.
A Novel Monopole Antenna with Two Arc-Shaped Strips for WLAN/WiMAX Application
Yoon, Joong Han ; Ha, Sung Jae ; Rhee, Young Chul ;
Journal of electromagnetic engineering and science, volume 15, issue 1, 2015, Pages 6~13
DOI : 10.5515/JKIEES.2015.15.1.6
In this paper, a novel monopole antenna for WLAN/WiMAX application is presented. The proposed antenna consists of two arc-shaped strips, a vertical strip, and a slot in the ground plane. In this study, a prototype of the proposed triple-band antenna was designed, fabricated, and tested. The quantitative and experimental results demonstrate that the proposed antenna satisfy the -10 dB impedance bandwidth requirement of 440 MHz for 2.4/2.5 GHz bands (from 2.26 to 2.70 GHz), 970 MHz for 3.5 GHz bands (from 3.27 to 4.24 GHz), and 870 MHz for the GHz bands (from 5.08 to 5.95 GHz), while simultaneously covering the WLAN and WiMAX bands. In addition, the presented triple-band antenna has an omnidirectional radiation pattern at all three frequency bands with an antenna gain of 4.45 dBi for the lowest band, 2.04 dBi for the middle band, and 3.98 dBi for the highest band.
Distributed Resource Partitioning Scheme for Intercell Interference in Multicellular Networks
Song, Jae-Su ; Lee, Seung-Hwan ;
Journal of electromagnetic engineering and science, volume 15, issue 1, 2015, Pages 14~19
DOI : 10.5515/JKIEES.2015.15.1.14
In multicellular wireless networks, intercell interference limits system performance, especially cell edge user performance. One promising approach to solve this problem is the intercell interference coordination (ICIC) scheme. In this paper, we propose a new ICIC scheme based on a resource partitioning approach to enhance cell edge user performance in a wireless multicellular system. The most important feature of the proposed scheme is that the algorithm is performed at each base station in a distributed manner and therefore minimizes the required information exchange between neighboring base stations. The proposed scheme has benefits in a practical environment where the traffic load distribution is not uniform among base stations and the backhaul capacity between the base stations is limited.
Circularly Rotated Array for Dual Polarized Applicator in Superficial Hyperthermia System
Kim, Ki Joon ; Choi, Woo Cheol ; Yoon, Young Joong ;
Journal of electromagnetic engineering and science, volume 15, issue 1, 2015, Pages 20~25
DOI : 10.5515/JKIEES.2015.15.1.20
A circularly rotated array for a dual polarized applicator in a superficial hyperthermia system is proposed. The applicator has a wider effective treatment area due to the
phase shift. The dual polarized circularly rotated array (DPCRA) suppresses overheating at the center of the array and helps evenly distribute the heat. This array provides a more effective treatment area than a lattice array when a
dual polarized array is fitted to the treatment area. The treatment area is 71.5% of the aperture, whereas the effective treatment areas of the
dual polarized lattice array (DPLA) and the single polarized array (SPA) are 57.2% and 38.6% of the same aperture, respectively. The measurement matches the simulation results without blood circulation effects. In a
array applicator, the proposed DPCRA has more heat uniformity than the DLA and the SPA.
A Simple Model for a DGS Microstrip Line with Stepped Impedance Slot-Lines
Woo, Duk-Jae ; Lee, Taek-Kyung ; Nam, Sangwook ;
Journal of electromagnetic engineering and science, volume 15, issue 1, 2015, Pages 26~30
DOI : 10.5515/JKIEES.2015.15.1.26
In this paper, a simple equivalent circuit model for a defected ground structure (DGS) microstrip line with stepped impedance slot-lines in the ground plane is presented. In addition, an analytic expression for the resonance frequency of the proposed structure is derived. In equivalent circuit modeling, the capacitance and the inductance of the resonance circuit are evaluated from the dimensions of the etched pattern in the ground plane. The resonance frequencies calculated from the proposed method are compared with those obtained with an electromagnetic (EM) simulation.
GA-Optimized Compact Broadband CRLH Band-Pass Filter Using Stub-Inserted Interdigital Coupled Lines
Jeon, Jinsu ; Kahng, Sungtek ; Kim, Hyunsoo ;
Journal of electromagnetic engineering and science, volume 15, issue 1, 2015, Pages 31~36
DOI : 10.5515/JKIEES.2015.15.1.31
The design of a new compact band-pass filter is proposed, which is based on the microstrip composite right- and left-handed transmission- line (CRLH-TL) structure. Particularly, the interdigital coupled (IDC) lines of the CRLH geometry are proposed to be parted by inserting open stubs to meet the specifications on the passband. In addition, there is another pair of stubs to complete the design in a limited space. These are considered in the TL-based analysis and the design parameters are calculated by genetic algorithm optimization. The measurement is shown to be acceptable and agreeable with the circuit and electromagnetic field simulations. In addition, the zerothorder resonance (ZOR) phenomenon is verified.
Implementation of High-Resolution Angle Estimator for an Unmanned Ground Vehicle
Cha, SeungHun ; Yeom, DongJin ; Kim, EunHee ;
Journal of electromagnetic engineering and science, volume 15, issue 1, 2015, Pages 37~43
DOI : 10.5515/JKIEES.2015.15.1.37
We implemented a real-time radar system for an unmanned ground vehicle designed to run on unpaved or bumpy roads. The system must be able to detect slow targets in a cluttered environment and cover wide angular sections with high resolution at the same time. The system consists of array antennas, preprocessors for digital beam forming, and digital signal processors for the detection process which uses sawtooth waveforms and high-resolution estimation, and is called forward/backward spatial smoothing beamspace multiple signal classification (FBSS BS-MUSIC). We show that the sawtooth waveforms enhance the angular estimation capability of FBSS BS-MUSIC in addition to their well-known advantages of removing the ambiguity of targets and detecting slow targets with improved velocity resolution.
Worst-Case Estimate of Envelope Correlation Coefficient for Small MIMO Mobile Antennas Below 1 GHz
Zhao, Xing ; Tak, Jinpil ; Choi, Jaehoon ;
Journal of electromagnetic engineering and science, volume 15, issue 1, 2015, Pages 44~52
DOI : 10.5515/JKIEES.2015.15.1.44
A worst-case estimate of an envelope correlation coefficient (ECC) is obtained for small multiple-input multiple-output (MIMO) mobile antennas operating below 1 GHz. The worst-case estimate is numerically derived in this paper using spherical and exponential wave functions. The derived result confirms that the worst-case ECC can be easily obtained from the rotation angle between the radiation patterns of two MIMO elements, which are attained directly from the amplitude of 2D electric field patterns without any additional phase and polarization information. As a practical example, MIMO mobile antennas with different antenna element arrangements are compared to verify the validity of the proposed worst-case estimate. Moreover, based on these analyses, we also suggest an effective approach to reduce the ECC of a small MIMO mobile antenna operating below 1 GHz by properly locating the antenna elements to make the radiation patterns perpendicular to each other.
Time- and Frequency-Domain Optimization of Sparse Multisine Coefficients for Nonlinear Amplifier Characterization
Park, Youngcheol ; Yoon, Hoijin ;
Journal of electromagnetic engineering and science, volume 15, issue 1, 2015, Pages 53~58
DOI : 10.5515/JKIEES.2015.15.1.53
For the testing of nonlinear power amplifiers, this paper suggests an approach to design optimized multisine signals that could be substituted for the original modulated signal. In the design of multisines, complex coefficients should be determined to mimic the target signal as much as possible, but very few methods have been adopted as general solutions to the coefficients. Furthermore, no solid method for the phase of coefficients has been proven to show the best resemblance to the original. Therefore, in order to determine the phase of multisine coefficients, a time-domain nonlinear optimization method is suggested. A frequency-domain-method based on the spectral response of the target signal is also suggested for the magnitude of the coefficients. For the verification, multisine signals are designed to emulate the LTE downlink signal of 10 MHz bandwidth and are used to test a nonlinear amplifier at 1.9 GHz. The suggested phase-optimized multisine had a lower normalized error by 0.163 dB when N = 100, and the measurement results showed that the suggested multisine achieved more accurate adjacent-channel leakage ratio (ACLR) estimation by as much as 12 dB compared to that of the conventional iterative method.
A Wideband H-Band Image Detector Based on SiGe HBT Technology
Yoon, Daekeun ; Kaynak, Mehmet ; Tillack, Bernd ; Rieh, Jae-Sung ;
Journal of electromagnetic engineering and science, volume 15, issue 1, 2015, Pages 59~61
DOI : 10.5515/JKIEES.2015.15.1.59
A wideband H-band detector operating near 300 GHz has been developed based on SiGe HBT technology. The detector consists of an on-chip antenna and a HBT differential pair for square-law detection. It showed responsivity of more than 1,700 V/W and noise equivalent power (NEP) smaller than
for the measured frequency range of 250-350 GHz. The maximum responsivity and the minimum NEP were 5,155 V/W and
, respectively; both were obtained at 330 GHz with DC power dissipation at 9.1 W.