• 전력전자학회논문지
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• 제2권2호
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• pp.57-63
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• 1997

고속 스위칭으로 동작하는 부스트 컨버터의 주 스위치자 ON/OFF 할 때, 주 스위치에 큰 전류나 전압이 가해질 수 있어서 스위칭 소자 파손을 초래할 수 있다. 이 스위칭 스트레스를 감소시키는 수단으로 스너버가 주로 이용된다. 최근에 스너버 에너지를 재생시켜 전력 컨버터의 에너지 효율을 향상시키는 방법들이 활발히 연구되고 있으나, 부가적인 제어가 필요없고 성능이 우수한 수동스너버에 대한 연구는 미진한 편이다. 본 연구에서는 부가적인 제어가 필요없고 에너지 재생이 가능한 수동 스너버를 가진 부스트 컨버터를 제안한다. 제안된 스너버를 갖는 부스트 컨버터의 제어는 종래의 제어방법과 동일하다. 또한 주 스위치의 전류 및 전압 스트레스를 감소시키면서 스너버 에너지를 출력으로 전달하는 에너지 재생 스너버의 구현은 몇 개의 소동 소자를 부가하여 구현된다. 제안된 회로에 대한 분석이 수행되고, 시뮬레이션 및 실험을 통해 유용성을 검증한다.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2000년도 전력전자학술대회 논문집
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• pp.434-438
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• 2000

In this paper the low cost sensorless control circuit for a PM synchronous motor without the mechanical rotor position sensors is presented. The sensorless control algorithm and position detection circuit for the sinusoidal current wave drive is more complex than that of the rectangular current wave drive. The proposed position sensing circuit is composed of an operational amplifier and several passive elements. The design procedures for getting the optimal parameters for the position sensing circuit are presented. The performance of the proposed algorithm is verified through the simulations and experiments.

• 전기의세계
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• 제28권9호
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• pp.35-40
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• 1979

A grounded inductor is proposed which contains only one resistor and operational amplifier. The circuit uses the inherent frequency dependent characteristic of an amplifier to simulate the inductor. A parallel resonance circuit is constructed with the proposed circuit. It has been proved by the experimental results of the resonant circuit that the proposed circuit is equivalent to the grounded lossy inductor. The lossy inductor is imbedded in a passive bandstop prototype, and the resultant characteristic curve has been verified by the experiment.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2001년도 Proceedings ICPE 01 2001 International Conference on Power Electronics
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• pp.98-103
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• 2001

In case that electronic ballast employing a valley-fill passive power factor correction (PFC) circuit is used for feeding fluorescent lamps, a new method to reduce crest factor of the lamp current is studied in this paper. In order to reduce crest factor to lower value, a pulse frequency modulation technique based on the waveform of the dc-link voltage which is predetermined by the passive PFC circuit, is taken into the switching control action of the electronic ballast. An equation-based analysis between the crest factor of lamp current and the effect of varying the inverter switching frequency is comprehensively performed.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2001년도 하계학술대회 논문집
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• pp.139-142
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• 2001

As microeletronics technology continues to progress, there is also a continuous demand on highly integration and miniaturization of systems. For example, it is desirable to package several integrated circuits together in multilayer structure, such as multichip modules, to achieve higher levels of compactness and higher performance. Passive components (i.e., capacitors, resistors, and inductors) are very important for many MCM applications. In addition, the low-temperature co-fired ceramic (LTCC) process has considerable potential for embedding passive components in a small area at a low cost. In this paper, we investigate a method of statistically modeling integrated passive devices from just a small number of test structures. A set of LTCC inductors is fabricated and their scattering parameters (5-parameters) are measured for a range of frequencies from 50MHz to 5GHz. An accurate model for each test structure is obtained by using a building block based modeling methodology and circuit parameter optimization using the HSPICE circuit simulator.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2000년도 춘계학술대회논문집
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• pp.1204-1209
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• 2000

Many analytical and experimental studies on the active suppression of nonlinear panel flutter by using piezoceramic patch have been carried out. However, these active control methods have a few important problems; a large amount of power is required to operate actuators, and additional apparatuses such as sensor systems and controller are needed. In this study passive suppression schemes for nonlinear flutter of composite panel, which is believed to be more robust suppression system than active control in practical operation, are proposed by using piezoelectric inductor-resistor series shunt circuit. Toward the end, a finite element equation of motion for an electromechanically coupled system is proposed using the Hamilton's principle. To achieve the best damping effect, optimal shape and location of the piezoceramic(PZT) patches are determined by using genetic algorithms. The results clearly demonstrate that the passive damping scheme by using piezoelectric shunt circuit can effectively attenuate the flutter.

• 한국전기전자재료학회논문지
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• 제15권4호
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• pp.344-348
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• 2002

As microelectronics technology continues to progress, there is also a continuous demand on highly integration and miniaturization of systems. For example, it is desirable to package several integrated circuits together in multilayer structure, such as multichip modules, to achieve higher levels of compactness and higher performance. Passive components (i.e., capacitors, resistors, and inductors) are very important fort many MCM applications. In addition, the low-temperature co-fired ceramic (LTCC) process has considerable potential for embedding passive components in a small area at a low cost. In this paper, we investigate a method of statistically modeling integrated passive devices from just a small number of test structures. A set of LTCC inductors is fabricated and their scattering parameters (s-parameters) are measured for a range of frequencies from 50MHz to 5GHz. An accurate model for each test structure is obtained by using a building block based modeling methodology and circuit parameter optimization using the HSPICE circuit simulator.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2002년도 하계학술대회 논문집
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• pp.135-138
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• 2002

VCO(Voltage Controlled Oscillator) is one of the main components governing the size, performance and power consumption of telecommunication devices. As the devices become much smaller, VCO need to have much smaller size with better characteristics. Buried type passive components of L,C,R were developed previously and the structure of these components are good for minimizing the size of VCO. Our own library of passive components is used in simulation and fabrication of VCO circuit, and surface mounted components like varactor diode are analysed using the measurement circuit designed by ourselves. Two-Dimensional simulation of VCO circuit and local three-Dimensional structure simulation are performed and their relation is obtained. In structure of multi-layered VCO, some components governing the characteristics of VCO are selected and placed on the top of oscillator for the good tuning process. In resonator part, the stripline structure and low loss glass/ceramic material are used to get higher Q value. In our research, a VCO oscillates in the 2.3∼2.36 GHz band is developed.

• 한국산업정보학회논문지
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• 제16권4호
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• pp.1-7
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• 2011

본 논문에서는 수동형 RFID 시스템을 이용한 무선 전력 전송을 위해 910MHz 대역에서 동작하는 정류회로를 두 종류의 쇼트키 다이오드 HSMS_2822와 HSMS_2852를 사용하여 설계한 후 입력 전력, 부하 저항에 따른 출력 전압을 측정하여 RF-DC 변환 효율을 비교 분석하였다. 입력 전력이 -20~17dBm에서 HSMS_2822를 사용했을 때보다 HSMS_2852를 사용한 경우 변환 효율이 더 높게 나타났다. 제작된 정류회로와 다이폴 안테나를 이용하여 RFID 리더기가 동작할 때 거리에 따른 수선되는 전압과 전류를 측정하였으며, 50cm 떨어진 거리에서 2.5V의 전압과 5.75mA의 전류가 측정되었다.

• 한국전자파학회논문지
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• 제14권11호
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• pp.1176-1183
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• 2003

본 논문에서는 1.6 ㎓ PCS 대역 초소형 전압제어발진기를 LTCC 기술을 이용하여 구현하였다. 상용부품들을 사용하여 VCO 회로를 설계하고, LTCC 기판 내부에 실장될 인덕터, 캐패시터들을 시뮬레이션을 통하여 최적으로 설계하였다. 설계된 수동소자들은 시뮬레이션을 위하여 등가회로로 모델링한 후 회로 파라메타를 추출하였다. 모델링된 내장형 부품과 21층 구조의 LTCC 기 판을 이용하여 전압제어 발진기를 설계하였으며, 4.0${\times}$4.0${\times}$1.6 ㎣ 크기의 VCO를 제작하였다. 제작된 전압제어 발진기의 동작전압은 2.7 V, 소모전류는 최대 8.5 ㎃ 이하이었으며, 동작주파수는 1,620∼l,650 MHz이다. 또한 동작주파수 내에서의 위상잡음특성은 100 KHz offset에서 -ll2.67 ㏈c/Hz의 우수한 특성을 지녔으며, -30 ㏈ 이상의 고조파억압특성을 보였다.