• Journal of the Korea Institute of Information and Communication Engineering
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• v.5 no.4
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• pp.817-821
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• 2001

In this paper, we design a microstrip patch antenna using 3-dimensional microstrip transition with the VSWR 1.3 over the PCS band (1.75 -1.87 GHz). We study experimentally the effect of the antenna parameters on antenna input impedance. And using the proposed antenna, we fabricate a polarization diversity any antenna and discuss the possibility of antenna for PCS base station.

• Proceedings of the IEEK Conference
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• 1998.06a
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• pp.153-156
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• 1998

구형도파관의 넓은 면에 축방향 슬롯을 파고 또 각각의 슬롯을 축방향으로 배열하였 때의 원거리 방사패턴을 구하는 과정을 보였으며 측정된 결과와 계산결과를 비교하였다. 방사전자계는 슬롯의 표면에 유기되는 등가의 자기전류로부터 계산할 수 있으며 임의의 개수를 가지는 배열안테나의 경우에는 각각의 슬롯이 자기 어드미턴스와 상호결합에 의한 영향을 받기 때문에 원하는 방사패턴을 얻기 위해서는 상호 어드미턴스를 고려하여 슬롯의 길이와 오프셋을 고려하여야 한다. 슬롯에서의 전계분포 해석은 모멘트법(method of moment)을 사용하여 해석하였다. 본 연구에서는 직선편파특성을 가지는 슬롯 배열 안테나의 설계를 위하여 슬롯의 자기 및 상호 어드미턴스를 구하고, 반복적인 수치해석 과정을 통하여 입력임피던스의 최적화 방법에 대하여 논하였다.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.46 no.2
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• pp.126-133
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• 2009

In this paper, The planar waveguide slotted antenna is presented for a satellite communication of vehicles. In stead of the microstrip patch array antenna having a dielectric loss and a feeding loss, the proposed antenna has the 3-layered waveguide feeding network structure for assembling easily. Also this antenna can receive mechanically both RHCP and LHCP transmitted from a satellite using a polarizer made from a thin single layer film. The Gain of the proposed 4X8 array antenna is 27.5dB and the gain of 8X16 array antenna is 32dB.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2017.05a
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• pp.61-62
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• 2017

In this study, a circular polarization patch antenna operates at the wide bandwidth of 1.5GHz~1.7GHz was designed. To obtain the wide bandwidth and high gain, the high air substrate was applied. The impedance bandwidth is improved by adjusting the sizes of patch, the distance between main patch and ground plate, the length of internal slots, the position of feeding point, the length of external stub, etc. The antenna is designed by simulation for an operation in the frequency range of 1.5GHz~1.7GHz band, and the antenna characteristics such as return loss, gain, radiation patterns are examined.

• Proceedings of the Korea Electromagnetic Engineering Society Conference
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• 2000.11a
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• pp.364-368
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• 2000

In this paper, we present the design and fabrication of a new circularly polarized circular patch antenna. The antenna is realized using a plastic foam sheet, a Teflon substrate and a metal-coated film. The radiating element is a circular patch proximity-fed by a wide microstrip line. Two thins slots are introduced on the circular patch to obtain a circular polarized radiation. The antenna is optimized using a commercial software. The antenna has 18% impedance bandwidth, 4% axial-ratio band width and 9.12dBi gain.

• Proceedings of the Korea Electromagnetic Engineering Society Conference
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• 2000.11a
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• pp.369-373
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• 2000

This paper describes a design for microstrip EMC cross dipole array antenna with circular polarization. To realize the wide bandwidth and circular polarization, the electromagnetic-coupled cross dipole is used. To obtain the uniform aperture illumination, offset technique for array is adopted. In 20-element array design, the calculated axial ratio and gain are about 0.1 dB and 9.9 dBi at 12GHz, respectively. The frequency characteristics of a fabricated 20-element array antenna are measured. The calculated results agree well with the measured ones.

• Proceedings of the IEEK Conference
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• 2003.11c
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• pp.327-330
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• 2003

A novel compact circular polarization operation of the microstrip antenna with four-slits and T-slits is proposed. The mechanism for compact size antenna is investigated with the behavior of the currents on the radiating patch. The equivalent surface current path due to the slits is lengthened, reducing the resonant frequency at a fixed patch size. The proposed compact CP design can have an antenna size reduction of about 33 ∼ 45％ as compared to the conventional microstrip antenna. Details of the experimental and measured results are presented and analysed.

• Proceedings of the Korea Institute of Applied Superconductivity and Cryogenics Conference
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• 2003.10a
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• pp.294-297
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• 2003

In this paper we designed and measured HTS antenna array for Direct Broadcast Satellite (DBS) system. HTS antennas fabricated in this work were a four-element, 11.67 ㎓z, high-Tc superconducting (HTS) microstrip antenna array with corporate feed network and circular polarization for direct broadcas- ting satellite (DBS) system. Our antennas was designed and built on a 0.5 mm thick YBa2Cu3O7-x (YBCO) /MgO substrate. The measurement results showed good axial ratio, wide bandwidth a remarkable improvement over their metal counterpart.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.43 no.5 s.347
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• pp.162-168
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• 2006

Understanding of propagation characteristics is very important for the wireless communication system design and wireless communication service construction. In this paper, propagation characteristics is measured and analyzed at 2.45Ghz frequency band under curved subway tunnel environment. We constituted channel measurement system with sliding correlation and five different kind of antennas. The purpose of five different type of antennas is to compare propagation characteristics according to beam shape of antennas. The path loss under tunnel environment is average $4.38^{\sim}14.41dB$ lower than free space and circular polarization antenna marked smallest path loss. Also, path loss is smallest when the receiver antenna located outside of tunnel in th curved section. 90% of delay components of all antennas measured within 20ns and directional antenna has more wide coherence bandwidth than omni-directional antenna. According to measured result, when we consider path loss and delay characteristics, circular polarization antenna is most suitable under tunnel environment.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.19 no.4
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• pp.404-410
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• 2008

In this paper, circular polarized microstrip antenna with a conducted hollow cylinder-typed via around the coaxial probe is proposed to enhance the bandwidth of an RFID portable reader microstrip antenna. An antenna of thickness of 6.4 mm and size of $84{\times}84\;mm$ is manufactured with FR4 substrate and its 10 dB return loss bandwidth is measured to be 92 MHz, which is about three times large than the same size's microstrip antenna without hollow cylindrical via. The measured antenna gain and the axial ratio at each are $0.01{\sim}1.825\;dB$ and $2.3{\sim}8.2\;dB$ within 10 dB return loss bandwidth, respectively.