• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 제36회 하계학술대회 논문집 C
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• pp.2300-2302
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• 2005

Metal-Semiconductor-Metal type photodetector was fabricated with AlGaAs/InGaAs Quantum Well FET structures using simplified processing steps. The DC and RF responses were measured by 850nm wavelength injection laser. A DC responsivity in the quasisaturated regime was 0.45 A/W in CW measurements, and a bandwidth measured using a 850nm 40 ps pulsed laser was 16GHz. An electrical equivalent circuit model was extracted from measured S-parameter.

• 한국마이크로전자및패키징학회:학술대회논문집
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• 한국마이크로전자및패키징학회 2003년도 기술심포지움 논문집
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• pp.208-213
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• 2003

본 논문에서는 mm대역에서 NRD를 사용하여 듀플렉스를 디자인하였다. 디자인된 듀플렉스는 두개의 단계적인 임피던스 필터와 T-junction으로 구성되어 있다. 단계적인 임피던스 필터는 무한 도파관의 등가회로모델과 리턴로스를 최소화하기 위해서 선택되어진 T-junction과 함께 디자인되었다. 듀플렉서의 특성은 기대되었던 결과와 함께 우수한 일치를 보여준다.

• JSTS:Journal of Semiconductor Technology and Science
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• 제5권2호
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• pp.113-119
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• 2005

4H-SiC planar MESFETs were fabricated using ion-implantation on semi-insulating substrate without recess gate etching. A modified RCA method was used to clean the substrate before each procedure. A thin, thermal oxide layer was grown to passivate the surface and then a thick field oxide was deposited by CVD. The fabricated MESFET showed good contact properties and DC/RF performances. The maximum oscillation frequency of 34 GHz and the cut-off frequency of 9.3 GHz were obtained. The power gain was 10.1 dB and the output power of 1.4 W was obtained for 1 mm-gate length device at 2 GHz. The fabricated MESFETs showed the charge trapping-free characteristics and were characterized by the extracted small-signal equivalent circuit parameters.

• 한국광학회지
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• 제15권4호
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• pp.349-354
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• 2004

XFP(10 Gb/s Small Form Factor Pluggable) 트랜시버 모듈에 사용되는 광송신 서브어셈블리(TOSA: Transmitter Optical Sub-assembly)를 열적, 전기적 측면에서 설계, 제작 및 평가하였다. 저가격이며 소형인 TOSA를 제작하기 위해서 바이어스 티 및 정합저항등을 AlN서브마운트 위에 집적하였다. 10 Gb/s의 초고속 전기 신호의 입력을 위해 CPW형 마이크로파 전송로를 스템 구조체내에 도입하였다. 소자의 전기적 특성 분석을 위해 서브마운트내에 실장되는 각종 전기광학 부품들과 스템 구조체들을 고속회로 모델링 하였다. 제작한 TOSA의 특성평가를 통해, 85$^{\circ}C$에서 11 GHz 이상의 -3 dB 대역폭을 얻을 수 있었다.

• 전기학회논문지
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• 제61권1호
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• pp.104-109
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• 2012

In this paper, we propose a way to improve the quality of L-band wireless communication from unfriendly influential factors lying in the neighboring RF bands. The UHF-band system has resonator components and they generate harmonics as the spurious in the L-band. Therefore, a metamaterial CRLH bandpass filter is designed for the purpose of system miniaturization and smaller insertion loss, and its spurious phenomenon is observed in the frequency domain. And its harmonics in the L-band are suppressed by a compact bandstop filter whose equivalent circuit is newly developed. The design methodology is validated by the equivalent circuit to be compared with commercial full-wave EM software simulations, where the spurious is dropped by 20dB. Also, the advantage of the proposed design is presented by the comparison where our filter is much smaller than the conventional parallel edge coupled filter by over 50%, with excellent harmonic suppression.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 1995년도 추계학술대회 논문집
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• pp.158-162
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• 1995

We report rf and power characteristics of AlGaAs/GaAs Heterojunction Bipolar Transistor (HBTs) for X-band power applications. HBTs have been fabricated with polyimide a an interlayer dielectric. By characterizing the DC and RF characteristics we obtained the maximum current gain of 45, BV$\_$CEO/ of 10 V, fT of 30 GHz and f$\_$max/ of 17 GHz for device with 6x14$\mu\textrm{m}$$^2$emitter size. To extract accurate equivalent parameters, the De-embedded method was applied for extraction of parasitic parameters and the calculation of circuit equations for intrinsic parameters. Based on the Load-pull method, power characteristics was simulated and measured to get the maximum output power of the device.

• KIEE International Transactions on Electrophysics and Applications
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• 제5C권3호
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• pp.124-130
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• 2005

In this paper, we designed a cylindrical type light source having an electromagnetic principle of inductively coupled plasma, and measured its electrical-optical properties. Using the transformer principle, an electrically equivalent circuit cylindrical type light source was analyzed. According to the parameters of electromagnetic induction, which were diameter of coil with cpO.3$\~$ 1.2mm, number of turns with 4$\~$ 12 turns, distance with 40$\~$ l20mm and RF power with 10$\~$ 150W, the electrical .md optical properties were measured. When the diameter of the coil was cp0.3mm, number of turns was 8 and distance was 40mm, and the maximum brightness of 29,730 cd/m$^{2}$ was shown with RF power l50W. The relationship between electromagnetic induction and plasma discharges was demonstrated using the mode transition from E-mode to H-mode

• 한국산학기술학회논문지
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• 제8권3호
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• pp.454-459
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• 2007

본 논문에서는 비정질 $Al_2O_3$ 코아 재료를 응용한 단순 solenoid 형태의 소형 고성능 RF 칩 인덕터를 연구하였다. 인덕터 크기는 $0.86{\times}0.46{\times}0.45mm^3$이고, $27{\mu}m$ 직경의 Cu를 코일로 사용하였다. RF 칩 인덕터의 인덕턴스(L), 양호 인자(Q), 임피던스(Z), 커패시턴스(C)와 등가회로 파라미터 등의 주파수 특성은 RF impedance/Material Analyzer (HP16193A test fixture가 장착된 HP4291B)로 측정되었다. $9{\sim}12$회의 권선수를 가진 RF 칩 인덕터들의 인덕턴스 값은 $21{\sim}34nH$ 범위를 가진다. 이들의 자기공진주파수(SRF)는 $5.7{\sim}3.7GHz$ 영역을 나타낸다. 또한 자기공진주파수가 증가함에 따라 인덕턴스 값이 감소하는 경향을 보이고 있다. 인덕터의 SRF는 인덕턴스가 증가함에 따라 감소하며, Q의 값은 $900MHz{\sim}1.7GHz$ 주파수 범위에서 최대 $38{\sim}49$까지 얻어졌다.

• 전자공학회논문지D
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• 제34D권12호
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• pp.54-61
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• 1997

An accurate extraction technique is developed to determine full euqivalent circuit parameters of Si MOSFETs using 1 set of measured S-parametes without complicated optimization process. This technique is based on the use of anlytic Z-parameters experessions for resistances and inductances and the Y-parameter ones for ntrinsic parameters. This accuracy is proved over the wide range of gate voltage by observing good agreement between measured and fitted Z-parameter equations and frequency-independent response of the extracted intrinsic parameters. Using this technique, gate voltage-dependencies of model parameters are obained in the saturation region and these results show the similar behavior to the short-channel effects expected from the device theory.

• 한국마이크로전자및패키징학회:학술대회논문집
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• 한국마이크로전자및패키징학회 2000년도 추계 기술심포지움 논문집
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• pp.23-27
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• 2000

Simultaneous Switching Noise (SSN) propagated through parallel power and ground planes in high-speed multilayer printed circuit boards (PCBs) causes malfunction of both digital and analog circuits. To reduce SSN, decoupling capacitors are generally used in the PCBs. In this paper, we improve the equivalent circuit model of decoupling capacitor in high-frequency range to analyze the effect of SSN reduction accurately. The analysis is performed by the microwave and RF design system (MDS) method and the finite difference time domain (FDTD) method. We compared the results by the ideal capacitor model with those by the proposed model.