• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2007년도 추계종합학술대회
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• pp.204-207
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• 2007

Film bulk acoustic wave resonator (FBAR) technology has attracted a great attention as a promising technology to fabricate the next-generation RF filters mainly because the FBAR technology can be integrated with current Si processing. The RF filters are basically composed of several FBAR devices connected in parallel and in series, and their characteristics depend highly on the FBAR device characteristics. Thus, it is important to design high quality FBAR devices by device or process optimization. This kind of effort may enhance the FBAR device characteristics, eventually leading to FBAR filters of high performance. In this paper, we describe the methods to more effectively improve the resonance characteristics of the FBAR devices.

• 전기학회논문지
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• 제56권5호
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• pp.905-909
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• 2007

Crystalline and micro-structural characteristics of ZnO thin films which were deposited on p-Si(100) with cooling naturally down of pre-heated substrate during RF magnetron sputter deposition, were investigated by XRD and SEM in this paper. The film which was prepared on the substrate which was pre-heated to $400^{\circ}C$ before deposition and then cooled naturally down during deposition, showed the most outstanding c-axis preferred orientation. The ZnO thin film having the best crystalline result were applied to SMR type FBAR device and resonance properties of the device were investigated by network analyzer. It showed that resonance frequency was 2.05 GHz, return loss was -30.64 dB, quality factor was 3169 and electromechanical coupling factor was 0.4 %. This deposition method would be very useful for application of surface acoustic wave filter or film bulk acoustic wave resonator.

• 한국초전도ㆍ저온공학회논문지
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• 제16권4호
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• pp.1-6
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• 2014

Superconducting quantum interference device (SQUID) is a sensitive detector of magnetic flux signals. Up to now, the main application of SQUIDs has been measurements of magnetic flux signals in the frequency range from near DC to several MHz. Recently, cryogenic low-noise radio-frequency (RF) amplifiers based on DC SQUID are under development aiming to detect RF signals with sensitivity approaching quantum limit. In this paper, we review the recent progress of cryogenic low-noise RF amplifiers based on SQUID technology.

• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제53권2호
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• pp.73-78
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• 2004

AIN thin film has been deposited on the $AI_2$$O_3$substrate with reactive radio frequency( RF) magnetron sputtering method. In this work, elelctromechanical coupling coefficient of AIN thin film was increased with an increase of AIN thin film thickness, and the maximum value was 0.11%. Insertion loss of SAW device was decreased with an increase of AIN thin film thickness and the minimum value was 33［㏈］. SAW velocity of IDTs/AIN/$AI_2$$O_3$structure and IDTs/AIN/$AI_2$$O_3$/Si structure were about 5480［㎧］and 5040［㎧］respectively.

• 한국항행학회논문지
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• 제13권4호
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• pp.503-508
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• 2009

본 논문에서는 특정인(장애인, 재활치료자, 고령자 등)들이 수월하게 컴퓨터를 사용 할 수 있도록 하기 위한 손동작 인식형 보조 입력장치를 설계하였다. 입력장치는 3차원 공간에서 손 동작 인식을 위해 자이로 센서를 사용하였고, 통신 대역은 무선 RF 2.4GHz 대역에서 신호를 송 수신 하도록 하였다. 제작된 보드는 자이로 모듈, RF 통신 모듈, MCU, USB 단자 등으로 구성되었다. 동작인식 실험결과, 마우스 기반의 커서 이동 및 프로그램 제어 등이 설계 규격대로 수행됨을 확인 하였다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 제36회 하계학술대회 논문집 C
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• pp.1992-1994
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• 2005

In this study, Bragg reflector was formed as tungsten(W) and $SiO_2$ deposited by RF magnetron sputtering according to variable conditions of RF power and working pressure to apply to the SMR type FBAR device, one of the next generation mobile communication devices. The micro-structural properties such as a crystal orientation, roughness and micro- structure were measured by XRD, AFM and SEM and the best condition of Bragg reflector was elicited with analyzing that results of the thin films about each conditions. Finally, FBAR device was fabricated with applying the Bragg reflector was formed on the best condition and measured the resonance properties and compared other research and considered it.

• 전자공학회논문지SC
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• 제46권1호
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• pp.49-54
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• 2009

본 논문에서는 무전원 상태에 놓인 발사체의 상태를 모니터링 하기 위하여 무선으로 발사체 내부에 있는 센서에 전력을 전달함과 동시에 센서에서 취득된 정보를 외부로 전달하는 역할을 수행하는 장치를 구현하는데 필요한 여러 가지 기술적인 부분에 대하여 살펴보았으며, 발사체에 적용되는 기술은 많은 시험과 신뢰성 시험을 확인 후 적용되는 사업임을 감안하여, 방사선 측정에 사용되는 측정기 센서 모듈 부분으로 대체하여 동일한 역할을 수행하도록 구성하여 실험하였다. 실험 결과 안테나간 거리 5cm에서 만족한 결과를 도출할 수 있었다.

• 한국초전도ㆍ저온공학회논문지
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• 제21권1호
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• pp.10-14
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• 2019

Radio-frequency (RF) amplifiers based on direct current (DC) superconducting quantum interference device (SQUID) have low-noise performance for precision physics experiments. Gain curves of SQUID RF amplifiers depend on several parameters of the SQUID and operation conditions. We are developing SQUID RF amplifiers for application to measure very weak RF signals from ultra-low-temperature high-magnetic-field microwave cavity in axion search experiments. In this study, we designed, fabricated and characterized SQUID RF amplifiers with different SQUID parameters, such as number of input coil turn, shunt resistance value of the junction and coupling capacitance in the input coil, and compared the results.

• 한국소음진동공학회논문집
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• 제21권3호
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• pp.206-211
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• 2011

In this paper, we report a high-precision wireless gap sensor based on a surface acoustic wave (SAW) device. The sensing element is a parallel-plate capacitor whose dimensions are $3{\times}3\;mm^2$, and is attached to the SAW device as an external load. The SAW device, equipped with an RF antenna, serves simultaneously as a signal conditioner and an RF transponder. The center frequency of the SAW device is 450 MHz. The wireless gap sensor prototype exhibits a resolution of 100 nm and a sensing range of $50{\mu}m$. The proposed sensor system can be used for remote, high-precision gap measurement in hard-to-reach environments.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2003년도 춘계학술대회 논문집 센서 박막재료 반도체 세라믹
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• pp.170-173
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• 2003

In this paper, we proposed a new bulk LDMOS structure which can be used for RF application, and its fabrication steps were introduced. The simulated devices consist of three types: Bulk device, SLB(SOI Like Bulk), and SOI device. As a result of process and device simulation, we showed electrical characteristics, such as threshold voltage, subthreshold slope, DIBL(Drain Induced Barrier Lowering), off-state current, and breakdown voltage. In this simulation study, the lattice temperature model was adopted to see the device characteristics with lattice temperature during the operation. SLB device structure showed the best breakdown characteristics among the other structures. The breakdown voltage of SLB structure is about 9V, that of bulk is 7V, and that of SOI is 8V.