• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.18 no.3 s.118
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• pp.315-322
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• 2007

In this paper, active integrated antenna with left hand circular polarization(LHCP) for a transmitter of UHF RFID reader has been described. A novel rectangular ring patch as a radiator of the active antenna is proposed for easier impedance matching, smaller patch size, and LHCP characteristics. An amplification circuit is placed in the opening area of the radiator and is combined with it to work as oscillating circuit around 915 MHz. From the test results, impedance bandwidth of 29 MHz, 3 dB axial ratio bandwidth of 20 MHz, 3 dB beamwidth of 85 degree, and effective radiation power of 8.8 dBm have been obtained.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.18 no.9
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• pp.2066-2072
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• 2014

In this paper, We proposed a UWB microstrip patch antenna with an O-shaped slot of the step structure and analyzed the characteristics of the antenna. In order to improve of frequency properties, size of the patch radiating element, radius change of the O-shaped slot, width of the feed line and a rectangular slot were optimized by CST simulation program. The proposed antenna showed that the 2.8GHz ~ 11.4GHz frequency, the minimum return loss and -10dB bandwidth were -32.39dB and 8.6GHz, respectively.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2012.10a
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• pp.307-311
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• 2012

In this paper, a novel particle swarm optimization method based on IE3D is used to design a mobile communication Microstrip Patch Antenna. The aim of the thesis is to Design and fabricate an inset fed rectangular Microstrip Antenna and study the effect of antenna dimensions Length (L), Width (W) and substrate parameters relative Dielectric constant (${\varepsilon}r$), substrate thickness on Radiation parameters of Band width. When the antenna was designed, a dual-band, dual-polarized antenna was used to secure the bandwidth and improve performance, and a coaxial probe feeding method so that the phased array of antenna is easy.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.23 no.12
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• pp.1327-1336
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• 2012

In this paper, the dual-faced monopole antenna, which is arranged by numerous rectangular ring patches in sequence for the multi-bands is proposed. The ring type structure of the patch can be increased the bandwidth. Therefore the bandwidth and beam width are improved by using multiple arrayed patches. When the ring type patches are inserted serially, the resonance frequencies are occurred by the current flow from the first ring patch. It is possible because the gap between the patches is very narrow. In addition, if the patches are composed on the same plane as the feed-line, fabrication could be very difficult because the gap between the patches is extremely narrow. The thickness and permittivity of the antenna, moreover, are very important parameters because both sides of the substrate are used. We finally found the optimal thickness and permittivity to generate the coupling effect by simulation. All patches are consisted of 4-steps which the patch size was decreased 85 % by each step. In conclusion, the resonant frequency bands are 1.75~2.6 GHz(850 MHz), 3.24~3.46 GHz(220 MHz), 3.8~4.0 GHz(200 MHz), and 4.4~4.9 GHz(500 MHz).

• 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.300-310
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• 2005

In this paper we propose the compact three-layer EBG structure. The unit cell of the proposed EBG structure is composed of a square patch in the upper layer and a square ring stripline in the lower layer that are connected to the ground plane through conducting vias. Reflection phase analysis method and tangential transmission method were considered to accomplish effective EM simulation and measurement. EM simulation results indicate that bandgap characteristics of the EBG structure using both methods is nearly identical. Parametric studies have been performed with the EM simulator to analyze the properties of the EBG structure by investigating the phase shift of the normally incident plane wave, and the transmission measurements between simple monopole antennas positioned near the EBGstructure have been done. The operating fiefuency bandgap of the proposed EBG structure is about 34 $\%$ lower than the conventional EBG structure with the same size. Measured results show bandgap from 0.930 GHz to 0.945 GHz.

• The Journal of the Korea institute of electronic communication sciences
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• v.13 no.1
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• pp.245-252
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• 2018

In this paper, the dual band circular polarization patch antenna was designed by using band rejection characteristics of CSRR structure for geostationary satellites. A quadrangular CSRR structure was etched on the ground at the rear of the patch antenna's feed to obtain band rejection characteristics in between the receiving frequency band(1525~1559MHz) and transmission band(1626.5~1660.5MHz), and the corner of the patch antenna was truncated to enable circular polarization. It was confirmed that the resonant frequency of the patch antenna differs according to the size anc location of the CSRR and cirular polarization characteristics with simulation and measurement results. Measurement results shows the gain of about 0.2dB and 1.5dB in the TX and RX band.

• Composites Research
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• v.22 no.3
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• pp.55-59
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• 2009

Microstrip antennas are low profile, are conformable to planar and nonplanar surfaces, are simple and inexpensive to manufacture, mechanically robust when mounted on rigid surfaces and are compatible with MMIC(Monolithic microwave integrated circuit) designs; they have been used in diverse communication systems. The rectangular microstrip patch antenna is designed for a central frequency of 12.5 GHz, and the final product is a $4{\times}1$ array antenna with curvature radius of 200 mm. The microstrip antenna is embedded in a sandwich structure which consists of skin and core material. After impact, the performance of damaged antenna is estimated by measuring the return loss and radiation pattern. The antenna performance was not affected by this impact damage.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.23 no.5
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• pp.583-591
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• 2012

In this paper, using a folded parasitic patch, a hybrid metamaterial antenna having the enhanced bandwidth is presented. To obtain a broad bandwidth of the antenna, a zeroth-order resonance(ZOR) mode of a mushroom antenna and a $TM_{010}$ mode of a conventional patch antenna are combined. By employing an etched rectangular hole and a folded parasitic patch in the conventional patch antenna, a resonance frequency of the $TM_{010}$ mode can be down-shifted toward that of the ZOR mode without changing the size of the antenna. Therefore, the proposed antenna has broad bandwidth which ranges from the ZOR mode to the $TM_{010}$ mode. As a result, a fractional bandwidth of the proposed antenna is measured as 12 % and a radiation efficiency is above 75 % in whole band.

• Proceedings of the Korea Society for Industrial Systems Conference
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• 1998.10a
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• pp.849-853
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• 1998

라인 해석법(Method of Line), MOL과 파수 영역 해석법(Space Domain Approach), SDA를 결합한 공간-파수 영역 해석법(SSDA)를 이용하여 MIC/MMIC 회로에서 임의 입체 구조를 갖는 공진기를 해석한다. SSDA는 상대 수렴(relative convergence)특성을 갖지 않으며, 반 해석적 (semianalytical )특성으로 수치적 효율이 높다. 경계치 문제로부터 씨스팀 행렬방정식 형태로 유도된그린 함수에 갤러킨법을 적용한다. 삼각, 사각 및 불연속 구조를 갖는 스트립 패치의 폭, 위치와 기판의 두께 변화에 따른 공진 주파수를 계산하였다.

• Proceedings of the Korea Society for Industrial Systems Conference
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• 1998.10a
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• pp.861-866
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• 1998

본 논문은 프로우브 급전한 주기적인 위상 배열 마이크로스트립 안테나의 계산된 결과를 제시한다. 수치적인 마들은 엄밀한 그린 함수와 캘러킨 (Galerkin)해에 근거를 둔다. 임의의면(plane)에서의 입력 임피던스를 스캔 각도에 따라 계산하여 반사계수를 구하고 유전체의 유전율과 두께가 위상 배열 안테나에 미치는 영향을 제시한다. 표면파에 의한 스캔 블라인드 현상을 설명하고 유전체의 두께에 따른 E-면과 H-면에서의 입력 임피던스 대역폭을 계산한다.