• 전기학회논문지
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• 제59권7호
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• pp.1282-1288
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• 2010

This paper proposes a novel microstrip patch antenna to make impedance matching possible by using slot/T-slot capacitive coupling between the patch and 50 $\Omega$ feed line on a ground plane. The single band/linear polarization patch antenna shows linear polarization at 2.4 GHz band. Under -10 dB return loss, the single band/linear polarization patch antenna obtains 50 MHz bandwidth at 2.37 GHz~2.42 GHz. The dual band/dual polarization microstrip patch antenna shows circular polarization at 2.4 GHz band and linear polarization at 3.1 GHz band. Under -10 dB return loss, The dual band/dual polarization microstrip patch antenna obtains 340 MHz bandwidth at 2.23~2.57 GHz and 375 MHz bandwidth at 2.95~3.325 GHz.

• 한국전자파학회논문지
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• 제17권7호
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• pp.605-614
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• 2006

본 논문에서는 설계 주파수인 1.575 GHz 에서 동작하는 마이크로스트립 안테나의 패치 크기 ( 공진 길이 )를 줄이기 위하여 패치의 양단 끝부분을 음각으로 구성하여 perturbation 효과를 적용한 3 차원 구조의 모자형 원형 마이크로스트립 안테나를 고안 및 설계하였다. 그 결과 반사 손실 - 26.59 dB, -10 dB 대역폭 65 MHz(4.13 %), 이득 4.66 dBd, - 3 dB 빔폭 E, H-면 각각 $79^{\circ},\;87^{\circ}$의 특성을 나타내었으며, 안테나 직경은 85 mm로 평면형의 97 mm에 비해 12 mm(12.4 %) 단축되어 23.2 %의 면적 축소율을 얻었다. 또한 패치의 크기를 더욱 소형화시키기 위하여 최적화시킨 양각 대 음각의 비와 점근선 각도를 조정하여 설계 주파수에서 동작하는 선형 편파 및 원형 편파 야구공형 원형 마이크로스트립 안테나를 설계 및 제작하였다. 선형 편파의 경우, 패치 직경은 74 mm로 평면형에 비해 41.8 %의 면적 축소율을 얻었으며, 원편파의 경우, 패치 직경이 82 mm로 평면형 선형 편파에 비해 28.5 %의 면적 축소율을 얻었다. 이로써 원형 마이크로스트립 안테나의 소형화에 perturbation 효과 적용이 유효함을 확인하였다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2004년도 하계학술대회 논문집 C
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• pp.2058-2060
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• 2004

In this paper, circular polarized antennas of Tx 30GHz and Rx 20GHz are implemented in LTCC process. Tx antenna has a circular patch structure and Rx antenna has a ring patch structure. The feeding line of Tx antenna is placed in the center hole of Rx ring patch antenna which is printed under Tx circular patch antenna layer. It makes antenna size smaller. Tx antenna's return loss in under -10dB level from 30GHz to 31GHz and Rx antenna is under -10 dB from 20GHz to 21GHz. The isolation between two antennas is less than -20dB. Axial ratio is less than 3dB though out each band.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2001년도 춘계종합학술대회
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• pp.223-227
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• 2001

마이크로스트립 패치 안테나가 갖는 협대역 특성을 보완하기 위하여 슬롯 패치 안테나를 광대역특성을 갖도록 설계하여 제작하였다. 마이크로스트립 슬롯 패치 안테나의 슬롯 크기와 급전부의 형태를 적절하게 설계하면 광대역의 특성을 가진 수 있다. 본 논문에서는 비유전율 10.6, 두께 50mi1인 epsilon-10 기판을 사용하여 원형 급전 구조인 인형 슬롯 안테나를 제작하였을 경우, 주파수 대역이 1.5∼2.28GHz으로 41%의 대역이 나타났다. 또한, 비유전율 4.75, 두께 1.6mm인 에폭시 기판에 사각형 급전 구조인 원형 슬롯 안테나를 제작한 결과, 주파수 대역 1.2∼2.7GHz으로 77％의 대역 특성을 얻었다. 이들 결과는 각각의 슬롯 형태 구조에서의 광대역 특성들을 얻을 수 있었다.

• ETRI Journal
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• 제32권3호
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• pp.468-471
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• 2010

A compact square patch antenna with reconfigurable circular polarization (CP) at 2.4 GHz is proposed. Circular polarization is generated by an arc-shaped slot on the ground plane. In order to switch the CP orientation, the current flow direction of the patch is reconfigured via the PIN diodes mounted on the slot. As the slot and bias circuit are not placed on the patch side, the proposed antenna radiates a CP wave without alteration in the main beam direction. From the experimental results, the impedance and CP bandwidths of the proposed antenna have been demonstrated for up to 80 MHz and 25 MHz, respectively.

• Journal of electromagnetic engineering and science
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• 제13권4호
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• pp.214-223
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• 2013

This paper proposes a theoretical analysis of hidden device detection and a design of multiband circular polarization patch array antenna for non-linear junction detector system application. A good axial ratio of circular polarization patch antenna is realized by a new approach that employs inclined slots, two rectangular grooves and a truncated ground for the conventional antenna. A good axial ratio of the 1.5 dB lower is measured by having an asymmetric gap distance between the ground planes of the coplanar waveguide feeding structure. The common ground plane of the linear array has an optimum trapezoidal slot array to reduce the mutual coupling without increasing the distance between the radiators. The higher gain of about 1 dBi is realized by using the novel common ground structure. The measured return loss, gain, and axial ratio of the proposed single radiator, as well as the proposed array antennas, showed a good agreement with the simulated results.

• Steel and Composite Structures
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• 제32권1호
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• pp.127-139
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• 2019

Bridges, offshore oil platforms and other infrastructures usually require at some point in their service life rehabilitation for reasons such as aging and corrosion. This study explores the application of adhesively bonded CFRP patches in repair of corroded circular hollow sectional (CHS) steel beams. An experimental program involving three-point bending tests was conducted on intact, corroded, and repaired CHS beams. Meso-scale finite element (FE) models of the tested beams were developed and validated by the experimental results. A parametric study using the validated FE models was performed to examine the effects of different CFRP patch parameters, including patch dimensions, number of plies and stacking sequence, on efficiency of the repair system. Results indicates that the corrosion reduced elastic stiffness and flexural strength of the undamaged beam by 8.9 and 15.1%, respectively, and composite repair recovered 10.7 and 18.9% of those, respectively, compared to undamaged beam. These findings demonstrated the ability of CFRP patch repair to restore full bending capacity of the corroded CHS steel beam. The parametric study revealed that strength and stiffness of the repaired CHS beam can be enhanced by changing the fiber orientations of wet composite patch without increasing the quantity of repair materials.

• 전자공학회논문지D
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• 제34D권1호
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• pp.1-7
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• 1997

In this paper, several parasitic elements are added to the circular microstrip antenna in order to increase its bandwidth. Three kinds of parasitic elements such as cone, circular plate, and ring types are applied and input VSWRs, radiation patterns, and input impedances are measured. The optimal sizes of each parasitic element are obtianed and the variations of the bandwidth according to the height from the patch are also measured. In thid case of the ring type, the optimum bandwidth is obtained at the height of 10mm from the patch to the parasitic element. In the cases of conical and circular plate types, the maximum bandwidth is obtained at the hight of 45mm form the patch to the parasitic elements.

• Journal of electromagnetic engineering and science
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• 제18권3호
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• pp.182-187
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• 2018

A low profile asymmetrical fractal boundary patch antenna based on reactive impedance surface (RIS) and a mushroom unit cell (MUC) is proposed and studied for dual band operation. The sides of the square patch antenna are replaced with asymmetrical half circled fractal curves for circular polarization operation at patch mode band. The fractal patch antenna is loaded with MUC for dual band operation. The antenna radiation characteristics are investigated and illustrated with both simulated and experimental results in detail. The 10-dB return loss bandwidth are 8.48% (3.21-3.49 GHz) and 2.59% (2.30-2.36 GHz) at upper and lower resonance frequencies, respectively. The 3-dB axial ratio bandwidth is 4.26% (3.21-3.35 GHz). A close agreement between simulation data with experimental results is observed.

• 한국전자통신학회논문지
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• 제7권6호
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• pp.1287-1292
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• 2012

본 논문에서는 주파수 1.525GHz~1.665GHz 넓은 대역에서 동작하는 이중편파 패치안테나를 설계 및 제작하였다. 넓은 대역폭 및 고 이득을 갖기 위해 GND기판으로 부터 Air층을 높게 적용하였으며, 광대역 축비 및 고 이득을 갖기 위해 기생패치를 적용하여 원하는 데이터를 얻을 수 있도록 하였다. 그 결과 안테나의 정재파비(VSWR)는 전 대역에서 1.9 이하를 나타내며, 반사손실 S11과 S22는 전 대역에서 -10dB이하로 시뮬레이션과 유사한 특성 결과를 얻었다. LHCP(Left Hand Circular Polarization) 및 RHCP(Right Hand Circular Polarization)의 격리 특성은 시뮬레이션 특성보다 더 개선되어 전 대역에서 -13dB이하로 만족한 결과를 얻었다.