• Journal of Advanced Marine Engineering and Technology
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• 제37권7호
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• pp.752-759
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• 2013

This paper presents a method for analyzing and designing an extremely miniaturized planar ring hybrid, using the combination of parallel and diagonally shorted coupled lines. In contrast to conventional miniaturized coupled line filters, it is proven that the required electrical length of transmission line can be largely reduced to even a few degrees, not only effectively suppressing the spurious passband but also approximately maintaining the same characteristic around the stable center frequency. A ring hybrid filter at center frequency of 1 GHz was fabricated on the FR4 epoxy glass cloth copper-clad plat (CCL) PCB substrate. The insertion loss of a ring hybrid filter with the die area of $30mm{\times}30mm$ is -4.68 dB. Simulated results are well agreed with the measurements.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 1998년도 추계학술대회 논문집
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• pp.101-104
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• 1998

A new planar-type micro gas sensor was designed and fabricated on silicon substrate and the operating characteristics of the sensor were investigated. The thin sensitive film of the sensor was fabricated by spin-coating of the SnO$_2$ sol solution which was synthesized by hydrothermal method. The spin-coating method for preparation of sensing layer was adopted to improve the long-term stability of the fabricated sensing film instead of physical methods such as rf sputtering and thermal evaporation. The fabricated microsensor showed a fairly good sensing performance for CO gas in air at 250$^{\circ}C$ The sensitivity(S=Ra/Rg) was shown to be about 5 to 2000ppm CO with heating power of 50mW.

• 한국광학회지
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• 제8권2호
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• pp.154-160
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• 1997

푸리에 변환의 일반형인 분수차 푸리에 변환(fractional Fourier transform : FRT)을 근간으로 하는 분수차 상관기는 입력패턴의 위치나 모양에 따라 상관결과치가 변하는 공간 가변 특성을 갖는다. 이러한 특성을 갖는 분수차 상관기를 푸리에 변환을 이용하는 기존의 상관기와 비교하였고, 분수차에 따른 상관결과치의 변화를 분석하였다. 정확한 분수차 상관함수의 계산을 위하여 광학부품들의 정렬에 있어서 고도의 정확도와 안정도를 갖는 평판 집적 광학계를 구성하였으며, 실험결과와 계산결과를 비교함으로써 평판 집적 광학계에 의한 분수차 상관기의 구현이 매우 정확히 수행될 수 있음을 검증하였다.

• 대한전자공학회논문지
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• 제26권10호
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• pp.1584-1590
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• 1989

In this study, a planar waveguide has been fabricated on a Y-cut LiNbO3 substrate by the Ti indiffusion technique and its guiding characteristics are measured by bright M-line spectroscopy. Using the photolithography method, an electro-optic grating modulator with interdigital electrodes has been fabricated by depositing Al on the Ti:LiNbO3 planar waveguide. And the beam intensity diffracted by the grating is measured as the applied voltage is increased.

• 전자공학회논문지A
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• 제29A권8호
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• pp.78-88
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• 1992

To improve the characteristics of sub$\mu$m short channel MOSFET device, a new device having the convex structure is proposed. This device has 3-dimensionally expandable channel length according to the vertical etched silicon height. For the purpose of comparing the DC and AC characteristics, planar device is also fabricated. Comparing the channel length, the convex device with 0.4$\mu$m silicon height is larger about 0.56$\mu$m in NMOS and 0.78$\mu$m in PMOS than planar devices. DC characteristics, such as threshold voltage, operational current, substrate current and breakdown voltage are compared together with AC characteristics using the ring oscillator inverter delay. Also process and device simulation are performed and the differences between convex and pranaldevice are also compared.

• ETRI Journal
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• 제28권2호
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• pp.216-218
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• 2006

This letter presents the design for a low-profile planar inverted-F antenna (PIFA) that can be stuck to metallic objects to create a passive radio frequency identification (RFID) tag in the UHF band. The designed PIFA, which uses a dielectric substrate for the antenna, consists of a U-slot patch for size reduction, several shorting pins, and a coplanar waveguide feeding structure to easily integrate with an RFID chip. The impedance bandwidth and maximum gain of the tag antenna are about 0.3% at 914 MHz for a voltage standing wave ratio (VSWR) of less than 2 and 3.6 dBi, respectively. The maximum read range is about 4.5 m as long as the tag antenna is on a metallic object.

• 산업기술연구
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• 제31권A호
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• pp.109-112
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• 2011

In this paper, we proposed a planar reversed triangle monopole antenna for UWB(Ultra Wideband) communication. RF-60A substrate of 0.64 mm thickness and 6.15 relative permitivity and 0.035 mm conductor of thickness and loss tangent 0.0025 is used for implementation. We have used Ansoft $HFSS^{TM}$(High Frequency Structure Simulator) to simulate the proposed antenna. The proposed antenna showed return losses about -10 dB, nearly omni-directional radiation patterns and maximum gains are over -5 dBi at the frequency band from 3.1 GHz to 10.6 GHz for ultra wide band communication.

• 한국전자파학회지:전자파기술
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• 제27권3호
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• pp.17-27
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• 2016

In the high-frequency characterizations of planar circuit components, measurement data may not be physical. It is mainly due to resonance effects concerned with discontinuities which are inevitable for a planar component characterization. In this paper, a novel accurate transmission line characterization method is presented that excludes the resonance effects based on measurement data reconfirmation. For the physically obvious data acquisition near the resonance frequencies of a transmission line, the additional lines with different line lengths are fabricated on the same substrate. The test transmission lines are characterized by using vector network analyzer (VNA) in 100 MHz to 26.5 GHz. It is shown that an accurate transmission line characterization can be achieved with the proposed measurement data reconfirmation technique.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2010년도 춘계학술대회
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• pp.662-664
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• 2010

본 논문에서는 5-10GHz 광대역 운용에 적합한 quasi-Yagi안테나를 설계하는 방법에 대해 연구하였다. Yagi 안테나는 단락종단된 마이크로스트립선로로 급전되며, 내장된 Balun 회로에 의해 정합되도록 하였다. FR4기판(비유전율 4.4, 두께 0.8mm)상에 제작된 안테나의 특성을 실험한 결과 컴퓨터 시뮬레이션에 의한 예상치와 잘 일치함을 관찰하였다.

• 한국전자파학회논문지
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• 제14권10호
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• pp.1044-1051
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• 2003

본 논문에서는 고유전율의 BMT 물질을 기판에 적용하여 기판 위에 소형화된 평면형 구조의 마이크로웨이브 듀플렉서를 설계, 제작하였다. Ba(Mg$_{1}$3/Ta$_{2}$3/)O$_3$(BMT)는 품질계수, 온도계수 측면에서 뛰어난 유전 특성을 보이며 유전상수가 23인 고유전 물질로서 회로의 크기를 줄이기 위한 기판에 적용하기가 적합하다. BMT 기판은 tape casting 공정에 의해 제작되었으며, 회로 패턴은 실크스크린을 이용하여 전극 패턴을 입혔다. Open-loop ring type의 듀플렉서를 BMT 기판 위에 설계, 제작하였으며 유전상수가 6.15인 상용 기판에 동일한 규격의 듀플렉서를 제작하여 비교한 결과, 특성의 저하 없이 약 80 % 정도 크기를 줄일 수 있었다. 따라서 제안된 BMT 기판은 예시된 듀플렉서 소형화를 구현하였으며, 마이크로웨이브 수동 소자의 소형화에 기여할 수 있을 것으로 기대된다.