• Journal of electromagnetic engineering and science
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• 제9권3호
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• pp.146-151
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• 2009

This paper presents a low-loss broadband balun that uses a coplanar waveguide-to-slotline field transformation. It operates over a very wide frequency range and is of compact size since it does not depend on a resonant structure. To analyse imbalance, the coplanar wavelength(CPW) input ground is connected to the CPW output ground through various capacitors to introduce common-mode impedances. As the common-mode impedance increased the imbalance became significantly higher at the higher-frequency band compared with the lower-frequency band. The bias-circuit approach is used to improve the operation bandwidth of the lower-frequency band. The measured results show a passband of 200 MHz to 2 GHz, an insertion loss of less than 0.75 dB, and a size of $20{\times}14\;mm$. The amplitude imbalance is approximately 0.3 dB and the phase imbalance is less than $6^{\circ}$ over the entire operational range.

• 센서학회지
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• 제14권4호
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• pp.286-290
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• 2005

We have demonstrated a refractometer for liquid based on a side-polished fiber. The device consists of a side-polished single mode fiber and a rectangular space which plays a role of the multimode planar waveguide when it is infused with a liquid. We presented a simple method to acquire the refractive index of a liquid by use of the spacings of periodic resonance wavelengths of the device. The resolution of the fabricated refractometer was order of $10^{-5}$

• 센서학회지
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• 제13권3호
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• pp.207-212
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• 2004

We have investigated the optical characteristics of a directional coupler made of a side-polished polarization maintaining fiber in contact with a multimode planar waveguide and its applications as sensors. A device structural condition to achieve the polarization insensitive wavelength response has been presented. The fabricated devices revealed a superior immunity to the bending and the deformation of PM fibers in the input section. It is experimentally shown that the proposed device is suitable for a remote fiber sensor.

• ETRI Journal
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• 제32권3호
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• pp.472-474
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• 2010

In this letter, a novel zeroth-order resonant (ZOR) antenna on vialess co-planar waveguide (CPW) is proposed. It is based on a composite right/left-handed CPW transmission line. To achieve a compact size, this antenna utilizes the ZOR condition, and its reactive parameters determine the resonant frequency. Each unit cell is composed of a metallic top patch and meander lines. Since it is realized on the CPW single layer, the proposed antenna has the benefits of being a compact size and easy to fabricate. The bandwidth of 6.8% and efficiency of 62% are experimentally achieved. Its bandwidth is enhanced compared with other ZOR antennas.

• Current Optics and Photonics
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• 제6권3호
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• pp.260-269
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• 2022

Segmented planar imaging detector for electro-optical reconnaissance (SPIDER) is an emerging technology for optical imaging. However, this novel detection approach is faced with degraded imaging quality. In this study, a 6 × 6 planar waveguide is used after each lenslet to expand the field of view. The imaging principles of field-plane waveguide structures are described in detail. The local multiple-sampling simulation mode is adopted to process the simulation of the improved imaging system. A novel image-reconstruction algorithm based on deep learning is proposed, which can effectively address the defects in imaging quality that arise during image reconstruction. The proposed algorithm is compared to a conventional algorithm to verify its better reconstruction results. The comparison of different scenarios confirms the suitability of the algorithm to the system in this paper.

• 한국통신학회논문지
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• 제17권4호
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• pp.371-378
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• 1992

본 논문에서는 Y-cut $LiNbO_3$ 기판 위에 TIPE 방식을 이용하여 평면 광도파로 렌즈를 제작하고 그 특성을 측정하였다. Ti 내부확산 평면광도파로 및 TIPE 평면 광도파로 제작하고, 프리즘 결합으로 굴절율을 측정하였다. 측정한 기본파 유효굴절율로부터 평면 광도파로 렌즈의 궤적을 구하여, 사진식각법과 lift-off기법을 이용하여 TIPE 평면 광도파로 렌즈를 제작하였다. 도파로를 따라 도파되던 광이 평면 광도파로 렌즈에 의하여 접속되는 현상을 관측하였고 측정한 결과와 컴퓨터 시뮬레이션의 결과가 잘 일치함을 알 수 있었다. 관측한 초점의 위치 및 크기가 설계한 값과 잘 일치하였다.

• 한국세라믹학회:학술대회논문집
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• 한국세라믹학회 2004년도 춘계총회 및 연구발표회 초록집
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• pp.50.4-50.4
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• 2004

• 한국광학회:학술대회논문집
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• 한국광학회 2007년도 하계학술발표회 논문집
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• pp.291-292
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• 2007

• 한국광학회:학술대회논문집
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• 한국광학회 2004년도 제15회 정기총회 및 동계학술발표회
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• pp.112-113
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• 2004

• 한국재료학회:학술대회논문집
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• 한국재료학회 1998년도 추계학술발표강연 및 논문개요집
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• pp.39-39
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• 1998