• Proceedings of the KIEE Conference
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• 2011.07a
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• pp.1656-1657
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• 2011

본 논문에서는 RF 프로브를 이용하여 평면 구조물의 RCS(Radar Cross Section)를 감쇄시키기 위한 방법을 제안하였다. 우선적으로, EM 시뮬레이터를 이용하여 제안한 방법에 대한 가능성을 증명한 후 실험을 수행하였다. x-band 에서 $10{\lambda}$의 알루미늄판 위에 FR4 기판을 이용하여 patch 형태로 제작된 RF 프로브를 설치하였으며, 그 후 알루미늄 판으로 입사되는 외부 전자파를 상쇄시키기 위하여 RF 프로브로부터 전자파를 방사하였다. 로테이터를 사용하여 알루미늄판을 phi 방향으로 회전하여 임의의 각도로 입사하는 평면파에 대해서도 반사파의 크기를 측정하였다. RF 프로브로부터 방사된 전자파의 세기와 위상은 신호 발생기와 위상 천이기를 이용하여 조절되었다. 결과적으로 무반향실에서의 실험을 통해, 알루미늄판에 의해 반사되는 전자파를 측정하여 외부 전자파의 상쇄 정도를 확인하였다.

• Journal of Auto-vehicle Safety Association
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• v.11 no.4
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• pp.50-56
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• 2019

Recently, automobile industries have developed ADAS, smart cars, connected cars, automated driving systems, which use a variety of sensor systems - ultrasonics, cameras, lidars and radars - and communication systems. It is necessary to examine the electromagnetic immunity of vehicles equipped with those systems. The electromagnetic immunity tests are carried out in an electromagnetic semi anechoic chamber, which is cut off from the outside. It is difficult to create test environments in which the radar sensor systems of vehicles work properly in the test chamber. In this study, test jigs were designed and tested and as a result they are shown to be effective to create test environments for electromagnetic immunity tests of vehicles equipped with radar sensors. We also proposed additional safety standards for immunity tests of vehicles with radar systems that currently do not exist.

• Journal of Auto-vehicle Safety Association
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• v.12 no.4
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• pp.7-12
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• 2020

Recently, automobile industries have developed ADAS, smart cars, connected cars, automated driving systems, which use a variety of sensor systems - ultrasonics, cameras, lidars and radars - and communication systems. It is necessary to examine the electromagnetic immunity of vehicles equipped with the sensor systems due to the fact that the normal operation of those systems is very important to the safety of the vehicles. The electromagnetic immunity tests are carried out in an electromagnetic semi anechoic chamber, which is cut off from the outside. It is difficult to create test environments in which the camera sensor systems of vehicles work properly in the test chamber. In this study, test jigs were designed and tested and as a result they are shown to be effective to create test environments for electromagnetic immunity tests of vehicles equipped with camera sensors. We also proposed additional safety standards for immunity tests of vehicles with camera systems that currently do not exist.

• Journal of Auto-vehicle Safety Association
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• v.14 no.1
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• pp.14-19
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• 2022

Recently, automobile industries have developed ADAS, smart cars, connected cars, automated driving systems, which communicate with outsides of a vehicle not only in uni-directional way but also in bi-directional way. It is necessary to examine the electromagnetic immunity of vehicles equipped with those communication systems. The electromagnetic immunity tests are carried out in an electromagnetic semi anechoic chamber, which is cut off from the outside electromagnetically. In this study, additional test environments were designed and tested and as a result they are shown to be effective to create test environments in an experimental chamber for electromagnetic immunity tests of vehicles equipped with communication systems.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.18 no.5 s.120
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• pp.503-510
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• 2007

This paper proposes the design scheme of internal triple band antenna intended for using in GSM900, DCS1800, and PCS1900 bands. The suggested folding metal plates of the two branches are mounted on a dielectric coated ground plane for size miniaturization and durability. Return losses are overlapped when length of metal branches are controlled. This is important technique for wide band operation. For the suggested antenna geometry its return loss was calculated by HFSS 9 simulator, and was shown to be -10 [dB] less within the required band. Also, gain and radiation pattern of antenna were measured using far field measurement system in an anechoic chamber. The measured peak gain is more than 3.0 [dBi], and the average gain is over -1.0 [dBi] for the triple band, which is regarded as satisfactory for the internal antenna application. Also, the radiation pattern for two frequencies shows a similar shape each other within the required band.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.16 no.3 s.94
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• pp.293-299
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• 2005

This paper introduces a program by which one can perform measurement, analysis, and simulation of electro-magnetic environment which affects on vehicular AV receivers. An integrated system of EM environment collected, GPS(Global Positioning System) informations, and developed simulation program can be an important evaluating tool for the analysis of automobile AV receivers.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.19 no.5
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• pp.515-522
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• 2008

In this paper, a slot antenna with built-in Bazooka balun aimed for a WiBro repeater was designed and fabricated. The return loss and radiation pattern of the slot antenna were improved due to the introduced Bazooka balun. This balun brings about even radiation pattern and keeps the stabilized coverage of repeater And it is easy to unite this balun with the antenna body by providing the terminal of Bazooka balun with screw shape. H-type slot was used to reduce the size of the antenna, and the slot antenna was fabricated in the structural symmetry with respect to a feeding point to afford the omni-directional radiation pattern. The simulated results were obtained by MWS(Microwave Studio Simulator) of CST company, and the measurement on the proposed antenna was conducted in an anechoic chamber equipped with a network analyzer and a far field measurement system. The measured peak gain shows 5.75 dBi and the average gain is above -0.8 dBi. The return loss remains below -12.35 dB for all frequency bands in WiBro regarded as a good performance.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.26 no.3
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• pp.248-256
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• 2015

In this paper, a hybrid MIMO antenna for the metal phone with auxiliary slot for 4th generation mobile communication is designed and implemented. Auxiliary slot locates on the rear metal cover of the phone, and handles for LTE class 40 band. The auxiliary slot operates hybrid with a monopole antenna. Studied antenna satisfies under VSWR 3:1 for LTE class 13/ LTE class 14/ CDMA/ GSM/ DCS/ PCS/ W-CDMA/ LTE class 40 bands. ECC(Envelope Correlation Coefficient) value for MIMO characteristic is less than 0.2 over the whole design bands. Average gains and antenna efficiencies measured by MTG anechoic chamber were -5.57~-1.45 dBi and 27.75~71.6 %, respectively.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.11 no.3
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• pp.437-444
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• 2000

In this paper, we propose a method that directly converts 3D CAD files for handheld phones designed by a commercial CAD S/W, PATRAN, to FDTD modeling with 1mm resolution. To qualify the accuracy of this method, we compared the calculation of radiation pattern using 3D transient far zone transformation with the measured results by gain comparison method in anechoic chamber and the difference is less than 0.5 dB. The calculation of magnetic field distributions on the front of handheld phones has been done to find a factor contributes to SAR. The result showed up the H-field in the width direction of the phone gives more dominant effect than the field in the length or inside to the front direction.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.27 no.4
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• pp.395-398
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• 2016

In this paper, a hybrid MIMO antenna for the mobile communication metal phone with auxiliary letter slot is designed and implemented. Auxiliary letter slot locates on the rear metal cover of the phone, and operates on LTE class 40 band. The slots of two letters are designed and operated with monopole+IFA hybrid antenna. Antenna satisfies under VSWR 3: 1 for LTE class 13 / LTE class 14 / CDMA / GSM / DCS / PCS / W-CDMA / LTE class 40 bands. Average gains and antenna efficiencies measured by the anechoic chamber were -5.57~-1.45 dBi and 27.75~71.6 %, respectively.