• Journal of the Korean Society of Radiology
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• v.3 no.2
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• pp.17-21
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• 2009

The thermal treatment have been combined with MRI which is able to acquire both an anatomical image with high-contrast and a thermal image, and have recently used for removing the tumor effectively. This study is to make a patch antenna which is designed to operate at 2.45GHz that has compatibility with MRI. The characteristic and specific absorption rate(SAR) were confirmed using computer simulation and confirmed a possibility of hyperthermia by performing experiment.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.12 no.4
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• pp.343-348
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• 2019

In this paper, a dual-band antenna is proposed for the autonomous vehicle as well as omni-directional. The proposed antenna operates in the 4G/LTE band (1,710~2,170MHz) and 5G/NR band (3,400~3,700MHz). In order to obtain the dual-band operation, the planar monopole antenna is proposed as the novel structure with single port of the 50ohm. To give the properties of dual-band, an additional antenna element with slit was added to the planar monopole antenna, and then a structural adjustment parameter was optimized for achieving the target performance in bands. The planar monopole antenna in the LTE band acts as the coupled feed for the added parasitic radiator in the 5G NR band. The proposed antenna has $38.5{\times}36.0{\times}1.0[mm^3]$ on a ground with diameter of 96mm. From the fabrication and measurement results, the impedance bandwidth (VSWR<2) of the proposed antenna covers 1,480~2,260MHz (LTE band: 1,710~2,170MHz) and 3,310~3,930MHz (5G NR band: 3,400~3,700MHz). The proposed planar monopole antenna also obtained the measured gain and radiation pattern of omni-directional radiation pattern in the anechoic chamber.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.8 no.4
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• pp.354-362
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• 1997

In this paper, a microstrip antenna with a small loop consisting of the left and right parallel plate to load a capacitor is proposed. It is obtained the improved high gain and bandwidth than the antenna consisting of the right parallel plate to load a capacitor on QMSA (Quarter-Wavelength Mi- crostrip Antenna). Also, the designed and manufactured antenna can receive both vertically and horizontally polarised waves to operating frequency of 1.5 GHz; therefore this is available as a small antenna for wireless telephones and will be quite useful for indoor communication.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.15 no.12 s.91
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• pp.1131-1140
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• 2004

In this paper, we proposed a flate-plate antenna employing semi-annular slots for satellite broadcast reception. The radiating element of the antenna is dual annular slots fed by a strip dipole, which have a wider bandwidth than the rectangular slot. A $16{\times}16$ array antenna is designed using stripline T-junction power dividers. Measurements of the fabricated antenna show a gain of 28.0$\~$29.5 dB in 11.7$\~$12.8 GHz frequency range.

• Journal of Broadcast Engineering
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• v.18 no.6
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• pp.911-918
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• 2013

The proposed print antenna using Finite Difference Time Domain(FDTD) method is analyzed in this paper. A low radiation resistance and an ultra-wide band of this antenna are also presented. The propagation process of the reflected wave and the electric field distribution in the time domain are calculated in respectively. The antenna parameters are optimized for the maximum band width, return loss, input impedance, and radiation pattern in the frequency domain using Fourier transforming. The experimental bandwidth of the antenna is 1.85GHz~6.35GHz for the VSWR less than or equal to 2.0. The measured results are relatively in good agreement with the FDTD results. The proposed antenna can be applied to various applications such as UWB, broadcasting-network system.

• Journal of IKEEE
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• v.24 no.1
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• pp.90-96
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• 2020

As various communication services have emerged due to the development of mobile communication technology, there is a need for a wideband antenna supporting multiple communication services with one antenna. In this paper, we propose a planar slot wideband antenna that can support all the communication services of 3.1~4.99GHz, the low frequency band of 5G, in addition to the existing communication services such as WiFi, LTE 2300/2500, and WiMAX. Through the simulation, the optimized antenna design parameters were obtained, and the antenna was fabricated to implement an antenna with a frequency bandwidth of 1.96~6.01GHz (S11 <-10dB) and presented the radiation pattern and gain of the antenna. The proposed antenna is a multi-band antenna that can provide all the services of LTE, Wifi, WiMAX, and 5G low frequency bands. It can be used as a repeater antenna in radio shadow area such as buildings, dense areas, and ships.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.07a
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• pp.127-130
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• 2003

4-bit 강유전체 위상변위기를 이용하여 10 GHz, 상온에서 작동하는 위상배열 안테나를 설계 및 제작하였다. 이 안테나는 빔 스캔을 위하여 전압에 대한 비선형특성을 보이는 강유전체 Bal-xSrxTiO3 (BST)를 기본으로 하는 위상변위기를 이용하였다. 우리는 펄스레이져 증착법으로 MgO (001) 기판위에 걸맞게 증착된 BST 박막을 일반적인 사진공정과 식각법을 이용하여 동일평판형 전극을 가진 위상변위기를 만들었다. 일반적인 동일평판형 강유전체 위상변위기의 경우 연결 전송선로의 임피던스와의 차이로 인해 반사손실과 이로 인한 부가적인 삽입손실이 발생한다. 이런 손실들을 줄이기 위해 입력과 출력 포트에 임피던스 매칭을 하였다. 이렇게 테이퍼링되어 만들어진 동일평판형 위상변위기는 이전의 구조에 비해 반사 손실과 삽입 손실 값에서 각각 약 10, 2 dB 정도씩의 개선을 보였다. 이 구조로 전송선로의 길이를 길게하여 만든 1-bit 강유전체 위상변위기는 10 GHz, 150 V의 전압변화에서 180도의 차등위상변위를 보였으며 최대 삽입손실과 최대 반사손실은 각각 약 10 dB, 20 dB 이다. 안테나 모듈은 4개의 마이크로스트림 패치 안테나와 4개의 강유전체 위상변위기로 이루어졌는데 10 GHz, 150 V의 전압변화에서 약 15도의 빔 스캔을 확인하였다.

• Proceedings of the Korean Society For Composite Materials Conference
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• 2000.11a
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• pp.195-198
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• 2000

Microstrip antenna for SAR applications is designed with microwave composite laminates and Nomex honeycomb cores, which becomes an aircraft's structural panel. This study demonstrated fabrication, design procedures and structural and electrical performances of complex antenna system presented. For validating structural rigidity, 3-point bending test is performed, and simulation results for the complex antenna array are compared with measurements for its electrical performance. The results show that this antenna system can be applied in dual polarized synthetic aperture radar and has a good flexural stiffness with comparison of previous sandwich constructions.

• Journal of IKEEE
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• v.23 no.3
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• pp.1112-1115
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• 2019

This paper proposes a novel low-profile omni-directional microstrip antenna to mount on the deployable wing of the observation munition. The proposed antenna is designed on seven hexagonal resonators in a quasi-circular array to achieve a monopolar radiation pattern with a thin substrate. By employing the mesh ground structures, the resonant frequencies and impedance bandwidths of the proposed antenna is investigated. To verify the feasibility of the mesh ground structure, the thin ground wire width is investigated theoretically for improving the 3-dB fractional bandwidth, realized antenna gain and quality-factor. The proposed antenna demonstrates a good monopolar radiation in good agreement with the simulation results. The implemented prototype shows the measured bandwidth of 326 MHz with respect to 5.65% centered at 5.77 GHz and realized gain of 5.49 dBi at 5.84 GHz.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2001.10a
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• pp.230-233
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• 2001

본 논문에서는 기존의 QMSA에 비해 안테나 전체 길이를 소형화함은 물론 전기력선이 미치는 범위가 제한받지 않도록 그라운드 판을 접어올린 좌측 평행 평판과 방사 패치사이 용량을 장하한 QMSA를 설계ㆍ제작하여 실제의 휴대전화기에 부착해서 안테나의 이득노화요인에 대해서 서술하였다. 안테나 성능 지표로서 휴대전화기케이스의 크기를 그라운드판으로 한 안테나를 설계하여 상용화된 HFSS프로그램에 의해서 리턴로스와 방사패턴등, 각종 손실을 고려한 개략적인 시뮬레이션을 행한 결과를 나타냈다. 또한 인체 근체에서 사용되고 있을 때의 휴대 전화용 안테나의 특성은 다른 사용상황에 있어서 안테나 급전점과 인체머리부분과의 간격, 인체머리부분과 안테나의 각도 등을 고려해서 인체에 미치는 전계강도를 시뮬레이션했다.