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DSP를 利用한 Phase-shifted PWM 直列共振型 DC-DC 컨버터
김현준,김학성,김세찬,유동욱,원충연 成均館大學校 科學技術硏究所 1995 論文集 Vol.46 No.2
This paper deals with a phase-shifted PWM high-frequency series resonant DC-DC converter using IGBTs. The converter output voltage regulation is digitally controlled using DSP(TMS320C31) for a fast rising time and low ripple output voltage. A PID controller and feed-forward controller is adopted as a controller and implemented on software. Simulation technique are employed to describe resonant converter behavior, which can present system output exactly and calculate in short time, by applying numerical method to the state equation of each equivalent circuit. And the simulation results are verified as compared with experimental results.
An UltraWideBand BALUN on Thin Film Substrate using MCM-D Technology
Chan-Sei Yoo,Ji-Min Maeng,Sang-Sub Song,Kwang-Hoon Lee,Jae-Hyun Yoon,Dongsu Kim,Hee-Seok Lee,Woo-Sung Lee,Kwang-Seok Seo 대한전자공학회 2007 ITC-CSCC :International Technical Conference on Ci Vol.2007 No.7
This paper presents a integrated balun using MCM-D technology for UWB application(3.1∼4.8 ㎓). Two types of circuit was suggested and compared. The first one using distributed circuit shows good power diving but poor phase shifting. On the other hand, the balun using lumped circuit shows good phase shifting but poor power dividing. To get good performance in both region, that is power dividing and phase shifting, the circuit using lumped and distributed one together was suggested and evaluated on the silicon substrate. Finally, the suggested balun shows good power imbalance(2 ㏈) and phase imbalance(10°). That can be integrated with the chipset using BEOL(back end of line) process.
RF Front-End Passive Circuit Implementation Including Antenna for ZigBee Applications
Yoo, Chan-Sei,Lee, Joong-Keun,Kim, Dongsu,Park, Seong-Dae,Won, Kwang-Ho,Kang, Nam-Kee,Seo, Kwang-Seok,Lee, Woo-Sung IEEE 2007 IEEE transactions on microwave theory and techniqu Vol.55 No.5
<P>This paper presents a front-end passive circuit module for ZigBee applications using low-temperature co-fired ceramic technology. The front-end part consists of an antenna, a bandpass filter, a switch, and two baluns. In antenna design, the solenoid shape is employed for reducing the size of the antenna, resulting in an overall size of 9times16.4times1.82 mm<SUP>3</SUP> and a gain of -1.4 dBi. As for the filter, two types of filters are suggested. First, the lumped-type filter employing a high-Q spiral inductor has more than 20-dB attenuation at both stopbands, very near to the passband. Secondly, the semilumped-type filter adopting an edge coupled line and a loading capacitor provides a group delay of below 5 ns and is adequate for the full module structure due to the structure flexibility. A balun is evaluated using lumped components instead of a transmission line and, thus, it provides an insertion loss of only 0.3 dB and a phase difference of 180deg between balanced signals. Based on these components, an RF front-end module including attaching pads for an RF integrated circuit (IC) and baseband IC is implemented. In case of using the lumped-type filter, the insertion loss of the front-end module is 6.5 dB, and the group delay is below 7 ns. In case of adopting the semilumped-type filter, the insertion loss is 6.2 dB, and the group delay is below 4 ns. The overall size of the former and latter is 25.14times28.5times0.68 mm<SUP>3</SUP> and 25.66times25.58times1.17 mm<SUP>3</SUP>, respectively</P>
Sangsub Song,Chan-Sei Yoo,Donghwan Kim,Sungsoon Choi,Jong-Chul Park,Kwang-Seok Seo IEEE 2006 IEEE MTT-S International Microwave Symposium diges Vol.2006 No.6
<P>In this paper, we developed millimeter-wave (mm-wave) integrated passives on the high-performance MCM-D technology considering flip-chip interconnection, which has the improved electrical, thermal, and thermo-mechanical performances for the flip-chip structure. These integrated passives using thin-film microstrip (TFMS) line include the Wilkinson power divider, the broad-side Lange coupler, the balun using the broad-side Lange couplers, and the band-pass filter. The fabricated Wilkinson power divider has an insertion loss less than 0.8 dB and better than 15 dB matching and isolation over a wide frequency range for W-band (75 GHz ~ 110 GHz). The broad-side Lange coupler shows the transmission and coupling loss of 3.8 plusmn 0.2 dB and return loss better than 18 dB in W-band. The developed balun exhibits that insertion loss is less than 2.5 dB and amplitude and absolute phase imbalance is less than 1.2 dB and plusmn3deg, respectively, in W-band. And the band-pass filter for the V-band application was designed and implemented with insertion loss of 2.6 dB at 56 GHz. These high-performance integrated passives on SNU's MCM-D technology can make mm-wave modules to be compact, high-performance, and low-manufacturing cost</P>
세라믹 VCO의 Block 특성 분석을 통한 주파수 튜닝
유찬세,이우성,Yoo Chan-Sei,Lee Woo-Sung 한국마이크로전자및패키징학회 2004 마이크로전자 및 패키징학회지 Vol.11 No.2
세라믹 모듈 내부에 내장되는 인덕터와 캐패시터와 같은 수동소자들은 주변 소자 및 패턴의 영향으로 모듈 내부에서는 변형된 특성을 갖게 된다. 이 때문에 수동소자들의 특성을 모듈내부에 내장된 상태로 추출하는 것이 가장 정확하다. 본 연구에서는 세라믹 VCO를 개발함에 있어서 전체 회로를 공진부와 발진부로 나누어서 각 block의 특성을 측정하였고 이를 통해 VCO의 고주파수 거동을 예측하여 개발에 활용할 수 있도록 하였다. Ceramic components and modules using LTCC passives are being performed and on the passives included in modules have been studied nowadays. However the characteristics changes of passives in ceramic module due to the coupling between patterns, so each block in module, must be analyzed in the state of module including coupling factors. In our research, characteristics of each block of VCO, resonator part, oscillator part, output part were measured and analyzed to allow the prediction of behavior of VCO.
Gwang-Hoon Lee,Chan-Sei Yoo,Jong-Gwan Yook,Jun-Chul Kim 대한전자공학회 2009 ITC-CSCC :International Technical Conference on Ci Vol.2009 No.7
This paper presents substrate integrated waveguide (SIW) cavity resonator, 4<SUP>th</SUP> order BPF and quasi-elliptic filter based on LTCC for 60 ㎓ application. The SIW cavity resonators with high Q factor are suggested and applied for the filter having low insertion loss and high selectivity, the resulting Qu value and the resonance frequency are 224.5 and 60.371 ㎓, respectively. The positive, negative and external couplings are applied to designs SIW filters, they are evaluated by the holes between resonators and the slots on ground planes and the signal line coupling slot, respectively. The proposed filters measured insertion loss is lower than 2 ㏈ and return loss is better than 11 ㏈. And quasi-elliptic filter selectivity is higher than 4<SUP>th</SUP> order BPF due to the effects of the high Q resonators and quasi-elliptic filter adapting the negative coupling.
Analysis of On-Wafer Passive Devices Embedded in Substrate
Je-Hyun Youn,Chan-Sei Yoo,Jong-Gwan Yook,Jun-Chul Kim 대한전자공학회 2009 ITC-CSCC :International Technical Conference on Ci Vol.2009 No.7
Chip in Substrate Package (CiSP) is that embeds system components in the Printed Circuit Board (PCB) and arranges them for a 3D structure. The 3D package methods such as CiSP have short wiring interconnections and thin volume, so these merits are suitable for miniature system packages. In this research, bare-chip inductors and capacitors are fabricated on the high-resistivity silicon wafer. These are embedded in the core of the multi-layer PCB, and via-holes interconnect metal layers. Inductance, capacitance, Q-factor, and the equivalent model get from DUTs and compare with bare-chips.
Evaluation of GaN Transistors Having Two Different Gate-Lengths for Class-S PA Design
Jun-Chul Park,Chan-Sei Yoo,Dongsu Kim,Woo-Sung Lee,Jong-Gwan Yook 한국전자파학회JEES 2014 Journal of Electromagnetic Engineering and Science Vol.14 No.3
This paper presents a characteristic evaluation of commercial gallium nitride (GaN) transistors having two different gate-lengths of 0.4-μm and 0.25-μm in the design of a class-S power amplifier (PA). Class-S PA is operated by a random pulse-width input signal from band-pass delta-sigma modulation and has to deal with harmonics that consider quantization noise. Although a transistor having a short gate-length has an advantage of efficient operation at higher frequency for harmonics of the pulse signal, several problems can arise, such as the cost and export license of a 0.25-μm transistor. The possibility of using a 0.4-μm transistor on a class-S PA at 955 MHz is evaluated by comparing the frequency characteristics of GaN transistors having two different gate-lengths and extracting the intrinsic parameters as a shape of the simplified switch-based model. In addition, the effectiveness of the switch model is evaluated by currentmode class-D (CMCD) simulation. Finally, device characteristics are compared in terms of current-mode class-S PA. The analyses of the CMCD PA reveal that although the efficiency of 0.4-μm transistor decreases more as the operating frequency increases from 955 MHz to 3,500 MHz due to the efficiency limitation at the higher frequency region, it shows similar power and efficiency of 41.6 dBm and 49%, respectively, at 955 MHz when compared to the 0.25-μm transistor.