• 한국정보통신설비학회:학술대회논문집
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• 2007.08a
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• pp.27-30
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• 2007

This paper deals with an equivalent circuit model for RF passive components. Rational functions are obtained from the frequency responses of EM simulation by using Foster canonical partial fraction expressions. The Vector Fitting(VF) and the Adaptive Frequency Sampling(AFS) scheme are also implemented to obtain the rational functions. A passivity enforcement algorithm is applied to ensure the stability of the equivalent circuit model. In order to verify the schemes, S parameters of the equivalent circuit model is compared to those of EM simulation in case of the microstrip line structure with 3 slots in ground.

• Proceedings of the KAIS Fall Conference
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• 2010.11a
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• pp.99-101
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• 2010

본 논문에서는 양면 마이크로스트립 구조와 결함접지구조(DGS)를 이용하여 저역통과여파기(LPF)를 소형화하여 설계한 결과를 제시한다. 기존의 연구에서는 DGS를 사용하여 LPF를 설계하는 것에 그쳤지만 본 연구에서는 양면 마이크로스트립 구조와 공통 DGS 구조를 이용하여 회로의 크기를 줄인 결과가 제안된다. 예로써 유전율이 2.2이고 두께가 31mils인 기판을 이용하여 LPF를 설계하고 그 결과를 제안한다. 제안한 방법에 의한 LPF의 특성이 종래 방법에 의한 것처럼 LPF로서 우수한 특성을 가진다는 것이 설명된다.

• Journal of Satellite, Information and Communications
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• v.12 no.1
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• pp.132-136
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• 2017

In this paper, expanded lowest operating frequency by adopting circular slot on ground of balun and balance improved balance performances by stacking dielectric layer balun is proposed. Bandwidth of proposed balun is 1~7 GHz, and electrical length is $0.05{\lambda}$ at 1 GHz. In order to check performances of the proposed balun, simple dipole is integrated with the balun and radiation pattern of dipole is measured.

• Journal of The Institute of Information and Telecommunication Facilities Engineering
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• v.8 no.1
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• pp.1-5
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• 2009

In this paper, we propose a method that applies Vector Fitting (VF) technique to the equivalent circuit model for RF passive components. These days wireless communication system is getting smaller and smaller. So EMI/EMC is an issue in RF. We can solve PI/SI (Power Integrity/Signal Integrity) that one of EMI/EMC problem apply IFFT for 3D EM simulation multiple with input signal. That is time consuming task. Therefore equivalent circuit model using RF passive component is important. VF schemes are implemented to obtain the rational functions. S parameters of the equivalent circuit model is compared to those of EM simulation in case of the microstrip line structure.

• 한국정보통신설비학회:학술대회논문집
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• 2009.08a
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• pp.281-284
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• 2009

In this paper, we propose a method that applies Adaptive Frequency Sampling(AFS) technique to the equivalent circuit model for RF passive components. Thes days wireless communication system is getting smaller and smaller. So EMI/EMC is an issue in RF. We can solve PI(Power Integrity)/SI(Signal Integrity) that one of EMI/EMC problem apply IFFT for 3D EM simulation multiple with input signal. That is time comuming task. Therefore equivalent circuit model using RF passive component is important. AFS schemes are implemented to obtain the rational functions. S parameters of the equivalent circuit moldel is compared to those of EM simulation in case of the microstrip line structure.

• Proceedings of the KIEE Conference
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• 2001.07c
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• pp.1858-1860
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• 2001

최근에 특정 주파수 대역에서 전자기파의 전파를 억제하는 주기 구조인 PBG(Photonic Band Gap) 구조에 대한 연구가 활발히 이루어지고 있다. 본 논문에서는 마이크로스트립 선로에서 사용될 수 있는 새로운 PBG cell을 제안하였다. 제안된 구조는 단일 cell 만으로도 대역저지 특성을 얻을 수 있고, cell의 치수를 조절하여 저지대역을 조절할 수 있다. 또한, 방사 효과 등으로 인한 손실을 고려하여 정확한 등가 모델링을 할 수 있다. 본 논문에서는 제안된 구조를 마이크로스트립 패치안테나의 하모닉 억제를 위해 사용하여 그 유용성을 입증하였다.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.41 no.4
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• pp.41-47
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• 2004

In this paper, we analyze the microwave characteristics of traveling-wave electro-absorption modulator (TW-EAM) considering the microwave feedline and the impedance mismatch. The TW-EAM is analyzed by using the equivalent circuit model. The capacitance and the inductance of the equivalent circuit are evaluated by using 3-dimensional finite difference time domain (FDTD) method, while the microwave feedline is analyzed by momentum method. In a viewpoint of microwave characteristics, we present the effect of the structure and the length of microwave feedline.

• Proceedings of the Korea Electromagnetic Engineering Society Conference
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• 2003.11a
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• pp.361-365
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• 2003

In this paper, we proposed the effective serial connection methodology of PBG resonator with defect mode. We use the big difference of impedance ratio in connection region, for example dual PBG, for serial connection. This method reduces the PBG cells and is able to control the pole of bandpass filters. This result in flexibility in design of bandpass filter. Our PBG bandpass filter is modeled by using the ideal transmission line model. This model is very easy, fast, and effective for PBG structure.

• Proceedings of the Korea Electromagnetic Engineering Society Conference
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• 2003.11a
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• pp.630-637
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• 2003

In this paper, a DBM(double balanced mixer) of 2 GHz is implemented on FR4(h=1.6mm, ${\epsilon}_r=4.6$) substrate. The structure of double balanced mixer requires, in general, two talons and a quad diode. For balun, a novel planar balun using microstrip to CPS(Coplanar Strip) is suggested and designed. The suggested balun shows the phase imbalance of $180^{\circ}{\pm}1.5^{\circ}$ and the amplitude imbalance of ${\pm}0.2 dB$ for 1.5 to 2.5 GHz. Using the balun, DBM is successfully implemented, and the measured conversion loss of up/down converter show about 6 dB over the bandwidth. The balun may be applicable for MMIC(Monolithic Microwave Integrated Circuit) DBM with the process supporting backside via though more study.

• Proceedings of the Korea Electromagnetic Engineering Society Conference
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• 2003.11a
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• pp.64-68
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• 2003

For the purpose of the efficient derivation of the closed-form Green's functions by which MoM matrix elements can be analytically evaluated, the optimum approximation path which is deformed from the Sommerfeld integration path on the complex $k_{\rho}$-plane is proposed based upon the steepest descent method and three level approximation procedure.