• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제53권11호
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• pp.577-582
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• 2004

In this paper, lumped equivalent circuits for a conventional parallel directional coupler are proposed. This equivalent circuits only have self inductance and self capacitance, so we can design exact lumped equivalent circuit. The equivalent circuit and design formula for the presented lumped element coupler is derived based on the even- and odd-mode properties of parallel-coupled line. By using the derived design formula, we have designed the 3dB and 4.7dB MMIC couplers at the center frequency of 3.4GHz and 5.6GHz respectively. Measurements for the designed MMIC directional couplers show at 4dB and 5.2dB-coupling value at the center frequency of 3.4GHz and 5.6GHz. Excellent agreements between simulation results and measurement results on the designed directional couplers show the validity of this paper

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2003년도 추계학술대회 논문집 Vol.16
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• pp.317-320
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• 2003

Nowadays, the study on the ceramic components and modules used in telecommunication system is being performed. Coupler is a microwave passive component used for power coupling or dividing and directional coupler is designed to be possible optional dividing percentage. In our research, We developed 14dB and 19dB directional couplers of DCS band. The good characteristics, the target insertion loss and high isolation, of couplers is obtained by LTCC processing using a ceramic material.

• 한국통신학회논문지
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• 제12권3호
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• pp.298-308
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• 1987

非均質性 媒質에 인덕티브와 캐패시티브의 結合係數를 동일하게 설계함으로 理想的인 非對稱方向性結合器의 實現을 가능케 함을 증명하고 非對稱方向性結合器의 設計節次와 例를 들었다.

• 전자공학회논문지B
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• 제32B권11호
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• pp.1481-1488
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• 1995

Due to the low loss, broadband and accurate short time delay properties of optical fiber, it has attracted as a delay medium for high speed and broad-band signal processing. In this paper, we consider the coherent optical fiber filter of IIR lattice structure, which uses coherent light sources and consists of directional couplers whose coupling coefficients are restricted between 0 and 1. Considering restrictions of directional coupler, the design formulae and condition for realibility of optical fiber filter of IIR lattice structure which makes the optimal use of optical signal energy are derived.

• 한국광학회:학술대회논문집
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• 한국광학회 2006년도 하계학술발표회 논문집
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• pp.493-494
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• 2006

Fabrication-error tolerant directional couplers are designed and analyzed. In the wavelength region of $1.55{\mu}m$, the coupling characteristics of the 3dB coupler is 50${\pm}$4%, when the waveguide width error is ${\pm}0.2{\mu}m$.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1997년도 추계학술대회 논문집
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• pp.568-571
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• 1997

The overall aim of this paper is to determine coupling loss factor using loss factor and structural loss factor. For this purpose, two kinds of loss factor were adopted. One is loss factor of each sub structure, another is structural loss factor based on the complex welded or assembled structure. Using these two parameters, it is possible to derive the coupling loss factor which represent characteristic condition of SEA theory. Coupling loss factor of conjunction in complex structure was expressed as power balance equation. The derived equation for a coupling loss factor has been simplified on the assumption of one directional power flow between two sub structures. Using these conditions, it is possible to find the coupling loss factor equation. The comparison between theory of power transmission on conjunction and above equation, show a good agreement in simple beam structure. To check the effectiveness of above equation, it was adopted rotary compressor. Rotary compressor has three main conjunctions between shell and internal vibration part. This equation was applied to find out the optimum welding point with respect to reduce the noise propagation. It shows the effective tool to evaluate the coupling loss factor in complex structure.

• 전자공학회논문지D
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• 제35D권7호
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• pp.25-31
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• 1998

Modal transmission-line is utilized to analyze the power coupling of optical directional coupler composed by two parallel guiding slabs. By defining a coupling efficiency .eta. amenable to rigorous supermodes and boundary conditions of modal functions, we evaluate the power transfer for TE mode of gainy coupler. The results reveal that optimized power exchange occurs at a novel wavelength .lambda.$_{op}$ , which is generally different from minimum gap .lambda.$_{min}$ between rigorous modes and phase-matching condition .lambda.$_{ph}$ .

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 1999년도 하계종합학술대회 논문집
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• pp.966-969
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• 1999

Using modal transmission-line theory (MTLT), we evaluate the power coupling of optical directional coupler composed by two parallel guiding slabs. The numerical results reveal that maximum power transfer occurs at a novel wavelength λ$_{opt}$, in which the excitation ratio of supermodes at input boundary is equal to each other, and it is generally different from minimum gap λ$_{min}$.in/.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2000년도 ITC-CSCC -2
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• pp.945-948
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• 2000

The coupling properties of supermodes guided by grating-assisted directional couplers (GADCs) can be phrased in rigorous modal theory. Such a modal solution for TE modes expressed by simple electrical transmission-line networks is utilized to analyze the power distribution of GADCS with three guiding channels. In particular, the modal transmission-line theory can serve as a template for computational algorithms that systematically evaluate the coupling efficiency that are not readily obtained by other methods.

• 한국전자파학회논문지
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• 제14권6호
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• pp.591-598
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• 2003

3중 결합 구조의 방향성결합기로 구성된 새로운 구조의 트랜스버살 필터를 제안하였으며 sinc 함수를 이용하여 제안된 필터의 결합계수를 간단하게 구하는 방법도 소개하였다. 최고 -3 dB의 결합도를 갖는 일반적인 방향성결합기를 이용한 기존의 트랜스버살 필터는 방향성결합기 사이를 연결해 주는 연결선로의 영향에 의해 주파수 특성이 저하되는데 제안된 구조의 필터는 특성 저하 현상이 현저히 개선되며 또한 높은 결합도가 요구되는 광대역 필터의 경우 삽입손실 특성이 우수하다. 그리고 같은 통과대역폭의 경우 방향성결합기와 연결선로의 수가 기존 필터보다 적으며 집적도에 더 유리한 구조를 가지고 있다. 제안된 구조의 필터 특성을 제작을 통해 고찰하였으며 계산치와 비교하였다.