• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2000년도 하계종합학술대회 논문집(1)
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• pp.260-262
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• 2000

Printed microstrip antennas are known to have limitations in terms of bandwidth by the presence of the dielectric substrate. In this paper, to overcome these limitations, a broadband microstrip bow-tie antenna which has two dip point for high speed wireless LAN, fabricated on a Taconic substrate is designed and simulated. In simualted results, the return loss is two dip point which is -28.5dB at 5.68GHz and -27dB at 5.85GHz. The bandwidth of this antenna is 8.7％ about VSWR$\leq$2 and 5.9％ about VSWR$\leq$1.5.

• Journal of electromagnetic engineering and science
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• 제10권3호
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• pp.171-174
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• 2010

In the paper, a printed dual-dipole array antenna is presented. A 4-way planar SIW power divider is adopted for feeding the array antenna. The dual-dipole is adopted as radiation elements which greatly improves the impedance band. The measured bandwidth larger than 31 % for VSWR$\leq$1.5 operating near 14 GHz is achieved and in agreement with the simulated results. The radiation E-plane and H-plane radiation pattern is presented in the paper. The radiation gain is also presented in the paper.

• Journal of Electrical Engineering and Technology
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• 제10권4호
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• pp.1738-1745
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• 2015

Radiation characteristics of a probe-fed rectangular microstrip patch antenna printed on a finite grounded high permittivity substrate are investigated systematically for various square grounded dielectric substrate sizes with several thicknesses and dielectric constants by experiment and full wave simulation. The effect of the substrate size on the radiation characteristics of a rectangular patch antenna is mainly determined by the effective dielectric constant of surface waves on a grounded dielectric substrate. As the effective dielectric constant of surface waves increases, the substrate sizes for the maximum broadside gain and the required onset for a large magnitude of squint angle decrease, while the variations of the broadside gain, the front-to-back ratio, and the magnitude of squint angle versus the substrate size increase due to the increase of the power of the surface wave.

• Journal of Power Electronics
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• 제17권5호
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• pp.1382-1390
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• 2017

This paper presents a power supply for gate drivers, which uses a magnetic resonance wireless power transfer system. Unlike other methods where multiple antennas are used to supply power for the gate drivers, the proposed method uses a single antenna in an insulated receiver to make multiple mutually isolated power supplies. The power transmitted via single antenna is distributed to multiple power supplies for gate drivers through resonant capacitors connected in parallel that also block DC bias. This approach has many advantages over other methods, where each gate driver needs to be supplied with power using multiple receiver antennas. The proposed method will therefore lead to a reduction in production costs and circuit area. Because the proposed circuit uses a high resonance frequency of 6.78 MHz, it is possible to implement a transmitter and a receiver using a small-sized spiral printed-circuit-board-type antenna. This paper used a single phase-leg circuit configuration to experimentally verify the performance characteristics of the proposed method.

• Journal of electromagnetic engineering and science
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• 제11권3호
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• pp.207-212
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• 2011

This paper presents a CPW-fed antenna with three slots. The proposed antenna can operate at 1.9~2.1 GHz and 2.9~3.3 GHz which are generated by the two rectangular slots, and 4.5~11.6 GHz which is generated by the main patch. The semicircle-slot is used as a band-notched filter to stop at a desired band (5.150~5.825 GHz) limited by IEEE 802.11a or HIPERLAN/2 applications. The currents concentrate around corresponding slots at the desired band. The proposed antenna is very small in size, with overall dimensions of $27{\times}32{\times}1\;mm^3$ etched onto an FR4-printed circuit board (PCB).

• 한국전자파학회논문지
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• 제14권5호
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• pp.444-449
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• 2003

본 논문은 IMT-2000 단말기용 인쇄기판형 안테나를 설계 및 제작하였다. 안테나는 FR-4($\varepsilon_{{\gamma}}$/=4.6) PCB 기판에 비아 홀(Via-hole)과 라인을 이용한 헬리컬 구조이며, 급전방식은 GCPW(Grounded Co-Planer Waveguide)로 구현하였다 상용 RF-Tool인 안소프트(Ansoft)사의 HFSS를 사용하여 안테나 구조를 설계하고,주파수 특성 및 복사 특성을 측정한 결과는 설계 주파수 대역인 1.920~2.170 GHz을 만족하였고, 2.045 GHz에서 공진하였으며, 321 MHz의 대역폭(VSWR<2.0) 특성을 나타내었다. 이때 안테나의 복사이득은 -l dBi 임을 확인할 수 있었다. 복사이득은 -l dBi 임을 확인할 수 있었다.

• Journal of Electrical Engineering and Technology
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• 제12권4호
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• pp.1611-1618
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• 2017

This paper presents a compact reconfigurable printed monopole antenna, operating in three different frequency bands (2.45 GHz, 3 GHz and 5.2 GHz), depending upon the state of the lumped element switch. The proposed multiband reconfigurable antenna is designed and fabricated on a 1.6 mm thicker FR-4 substrate having a relative permittivity of 4.4. When the switch is turned ON, the antenna operates in a dual band frequency mode, i.e. WiFi at 2.45 GHz (2.06-3.14 GHz) and WLAN at 5.4 GHz (5.11-5.66 GHz). When the switch is turned OFF, it operates only at 3 GHz (2.44-3.66 GHz). The antenna radiates omni-directionally in these bands with an adequate, bandwidth (>10 %), efficiency (>90 %), gain (>1.2 dB), directivity (>1.7 dBi) and VSWR (<2). The fabricated antenna is tested in the laboratory to validate the simulated results. The antenna, due to its reasonably compact size ($39{\times}37mm^2$), can be used in portable devices such as laptops and iPads.

• 전자공학회논문지
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• 제52권2호
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• pp.55-69
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• 2015

근접 결합 급전 방식을 이용한 마이크로스트립 패치 안테나의 급전 선로에 임피던스 정합기를 집적하여 대역폭을 확장하는 방법에 대하여 연구하였다. 여러 가지 유전상수와 두께를 가지는 기판을 사용한 근접 결합 급전을 이용한 패치 안테나에 임피던스 정합기를 집적한 경우와 임피던스 정합기를 사용하지 않은 경우의 대역폭과 방사특성을 비교하였다. 임피던스 정합기를 사용한 경우가 사용하지 않은 경우에 비하여 방사특성의 저하 없이 대역폭이 크게 증가함을 볼 수 있었다.

• 산업기술연구
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• 제22권B호
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• pp.155-161
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• 2002

As the wireless communications are gradually developed, the higher frequency is demanded and the smaller the size of antenna shall be reduced by the wavelength of the operating frequency. However, the smaller the size of antenna becomes, the less the gain is obtained according to the frequency, so that a new attempt such as an array antenna has been examined to improve the characteristics. Also, for the convenience of communication, the omni-directional property is required. In this paper, two antennas system which is aligned in cross direction in tested and analyzed. The main scope is focused to get an appropriated distance between the two small antennas to get better properties. There are various ways of array arrangement, but in this study, it should be placed on the same PCB for easy implementation and the direction of each antenna are aligned to be a cross($90^{\circ}$) position. The study is carried out by comparing the radiation patterns mainly, and the theoretical expectation and the computer simulation are also executed. The final model is the folded IF-antennas system printed on PCB and the ideal dipole-antenna arrangement in also test to verify the possibility of our implementation. And it is finally proved by measuring experiments.

• 방송공학회논문지
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• 제18권6호
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• pp.911-918
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• 2013

본 논문에서에서는 방사저항이 낮고, 다중 공진을 갖는 초광대역 특성을 갖는 평판형 안테나를 FDTD법을 적용하여 그 특성을 분석하였다. 본 안테나를 FDTD 법을 사용하여 모델링하여 파의 전파 과정, 전계 분포를 시간영역에서 각각 계산하였고, FDTD 법으로 얻은 값들을 Fourier 변환하여 최적화된 슬롯 안테나의 전반사손실, 정재파비, 복사패턴을 주파수 영역에서 계산하였다. 실험 및 측정한 결과, 안테나의 최대 대역폭은 VSWR ${\leq}$ 2.0 에서 1.85~6.35GHz(중심주파수 4.5GHz)의 초광대역 특성을 보였다. 측정된 결과는 FDTD 결과와 비교적 잘 일치하였다. 본 안테나는 소형이고 경량이면서 초광대역 특성을 요구하는 UWB, 방송용 시스템에 적용이 가능하리라 판단된다.