• KEPCO Journal on Electric Power and Energy
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• 제6권4호
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• pp.473-480
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• 2020

In this paper, we proposed a high frequency equivalent circuit considering parasitic impedance components for differential noise analysis on the input stage during DC-DC buck converter switching operation. Based on the proposed equivalent circuit model, we presented a method to measure parasitic impedance parameters included in DC bus plate, IGBT, and PCB track using the gain phase method of a network analyzer. In order to verify the validity of this model, a DC-DC prototype consisting of a buck converter, a signal analyzer, and a LISN device, and then resonance frequency was measured in the frequency range between 150 kHz and 30 MHz. The validity of the parasitic impedance measurement method and the proposed equivalent model is verified by deriving that the measured resonance frequency and the resonance frequency of the proposed high frequency equivalent model are the same.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2004년도 ICCAS
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• pp.466-469
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• 2004

In this paper, we improve the matching impedance of antennas by inserting parasitic slots on the ground plane of right-angle triangular slot antennas. The designed antennas characteristics are analyzed by using Finite Different Time Domain (FDTD) method, the specific design frequency is 10 GHz and match impedance is 50 ohms. Simulation results show that the efficient of return loss and radiation patterns are improved and enhance. In this case, the right-angle triangular slot antennas with parasitic slots have matching impedance better than antennas without parasitic slots.

• 한국전자파학회:학술대회논문집
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• 한국전자파학회 2003년도 종합학술발표회 논문집 Vol.13 No.1
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• pp.511-514
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• 2003

In this paper, describes the design of PIFA for PDA which has parasitic patch to expand the impedance bandwidth and miniaturization technique to consider the radiation pattern. To expand the impedance bandwidth, generated resonant frequency of parasitic patch is different from that of main patch. To miniaturize the physical dimension, using the folded edge and rectangular slot. The obtained impedance bandwidth is 9.4% ($2.29GHz{\sim}2.515GHz$) at VSWR${\leqq}$2 and antenna gain is 2dBi within the operating frequency.

• Journal of electromagnetic engineering and science
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• 제7권3호
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• pp.116-121
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• 2007

Novel design of a wideband monopole antenna for DVB-H service is presented. The proposed antenna is designed based on a monopole antenna. It consists of folded monopole and parallel parasitic element. The folded segment of the folded monopole makes the antenna shorter. The length of the parasitic element obtains additional resonance frequencies. The gap distance between the folded monopole and the parasitic element is a key parameter to control impedance matching for wideband operation. The antenna has wide band performance, good impedance and radiation characteristics from 470 MHz to 870 MHz. The measured return loss for operating frequencies over DVB-H band is better than 10 dB. Good radiation patterns are also obtained. The measured results are compared with calculated results using Ansoft HFSS(High Frequency Structure Simulator).

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2016년도 춘계학술대회
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• pp.83-84
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• 2016

본 논문에서는 직사각형 및 삼각형 기생 패치를 이용한 광대역 마이크로스트립 패치 안테나를 제안하였다. 직사각형 마이크로스트립 패치 위에 직사각형 및 삼각형 모양의 기생 패치들을 적층하여 860MHz대역에서 광대역 특성을 얻었다. 주 방사부인 마이크로스트립안테나와 기생 패치와의 효과적인 결합은 이들 사이에 두꺼운 공기층을 두어 구현하였다. 또한, 이들 공기층 두께와 기생 패치의 위치는 광대역 정합에 중요한 요소임을 알 수 있었다. 제안된 안테나는 $119mm{\times}109mm$ 크기의 소형 접지면 위에 설계되었으며, 안테나의 임피던스 대역은 780MHz~890MHz로 CDMA 대역을 만족한다.

• Journal of international Conference on Electrical Machines and Systems
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• 제3권3호
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• pp.339-353
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• 2014

A straightforward method for optimal determining of a high frequency inductor's parasitic capacitance is presented. The proposed estimation method is based on measuring the inductor's impedance samples over a limited frequency range bordering on the resonance point considering k-dB deviation from the maximum impedance. An optimized solution to k could be obtained by minimizing the root mean squared error between the measured and the estimated impedance values. The model used to provide the estimations is a parallel RLC circuit valid at resonance frequency which will be transferred to the real model considering the mentioned interval of frequencies. A straightforward algorithm is suggested and programmed using MATLAB which does not require a wide knowledge of design parameters and could be implemented using a spectrum analyzer. The inputs are the measured impedance samples as a function of frequency along with the diameter of the conductors. The suggested algorithm practically provides the estimated parameters of a real inductance model at different frequencies, with or without design information. The suggested work is different from designing a high frequency inductor; it is rather concentration of determining the parameters of an available real inductor that could be easily done by a recipe provided to a technician.

• 한국전자파학회논문지
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• 제12권7호
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• pp.1076-1085
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• 2001

본 논문에서는 균일한 유전체 내의 복잡한 3차원 구조체에 대한 효율적인 기생(Parasitic) 임피던스 성분 추출을 위하여 반복법의 일종인 GMRES(Generalized Minimal RESidual Method)와 결합된 고속 멀티폴(FMM : Fast Multipole Method) 알고리즘을 구현하였다. 이 알고리즘은 준정적 기반 고속 멀티폴 방법으로 다중 도체들 간의 임피던스를 계산하는데 있어 기존의 모멘트법(MoM: Method of Moment)이 가지고 있는 계산량과 시간의 문제를 극복하기 위한 고속화 기술이다. 본 논문에서는 기존 MoM과의 비교를 통해 FMM의 정확성과 효율성을 입증하였다. 또한 멀티폴 알고리즘을 이용하여 기존 MoM으로는 해석이 불가능한 FC-PGA (Flip Chip Pin Grid Array) 패키지 핀에서의 기생 임피던스 성분들을 추출함으로써 신호간의 간섭에 의한 EMI/EMC 문제의 발생 가능성을 확인하였다.

• 전력전자학회논문지
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• 제20권2호
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• pp.137-143
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• 2015

This paper presents the intra capacitance modeling based on the winding method and section bobbin for CM choke capable of EMI attenuation of broad bands from lower to higher frequency bands and high frequency type common-mode choke capable of EMI attenuation of high frequency band used in the EMI Block of LED-TV SMPS. The case of high frequency type CM choke can be explained by the parasitic capacitance of three types of CM choke. The winding method of section bobbin type is smaller than the others. The first resonant frequency of the proposed CM choke tends to increase as the parasitic capacitance becomes small and its impedance characteristics improved performance as the first resonant frequency increases. The CM chokes of the proposed section bobbin type shows that in the future, the method may have practical use in LED/LCD-TV SMPS and in several applications, such as LED lighting, adapters, and so on.

• 한국정보통신학회논문지
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• 제20권5호
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• pp.874-879
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• 2016

본 논문에서는 직사각형 및 삼각형 기생 패치를 이용한 광대역 마이크로스트립 패치 안테나를 제안하였다. 직사각형 마이크로스트립 패치 위에 직사각형 및 삼각형 모양의 기생 패치들을 적층하여 860MHz대역에서 광대역 특성을 얻었다. 주 방사부인 마이크로스트립안테나와 기생 패치와의 효과적인 결합은 이들 사이에 두꺼운 공기층을 두어 구현하였다. 또한, 이들 공기층 두께와 기생 패치의 위치는 광대역 정합에 중요한 요소임을 알 수 있었다. 제안된 안테나는 향후 소형 트랜시버에 적용하기 위해 $119mm{\times}109mm$ 크기의 소형 접지면 위에 설계 및 제작되었다. FR4기판에 제작된 안테나의 임피던스 대역은 818~919MHz(11.7%)이다. 방사패턴은 기존 마이크로스트립 패치 안테나와 유사했으며, 최대 이득은 주파수 824MHz에서 2.11dBi로 측정되었다.

• 전력전자학회논문지
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• 제19권1호
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• pp.8-14
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• 2014

This paper presents the intra capacitance modeling according to the winding method and section bobbin for CM choke capable of the EMI attenuation of broad bands from lower frequency bands to higher frequency bands and high frequency type common-mode choke capable of the EMI attenuation of high frequency band used in the EMI Block of LED-TV SMPS. In case of high frequency type CM choke, it can be explained the parasitic capacitance of A type and section bobbin type winding methods among them is much smaller than the other. The first resonant frequency of the proposed CM choke tends to increase as the parasitic capacitance becomes small and its impedance characteristics also show improved performance as the first resonant frequency increases. In the future, the CM chokes of high frequency type show it can be practically used in not only LED/LCD-TV SMPS but also several applications such as LED Lighting, Adapter and so on.