• Proceedings of the IEEK Conference
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• 2002.07b
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• pp.767-769
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• 2002

A novel RE configurable device composed by bare-chip, bumps and board are proposed. We call this "Field-Programmable RF Gate Array (FPRA)," This device, a kind of programmable system packages, has a potential to be applied to wireless communication terminals such as software-defined radio.

• Advances in nano research
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• v.3 no.1
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• pp.39-47
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• 2015

We study a device structure which can be used to generate pure valley current and valley polarized current using quantum adiabatic pumping. The design of the structure allows the flexibility of changing the structure from one for pure valley current generation to one for valley polarized current generation by changing the applied electric potentials through changing the symmetry of the structure. The device is useful for the development of valleytronic devices.

• Proceedings of the KIEE Conference
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• 1990.11a
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• pp.380-383
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• 1990

When the MOSPET is applied as a switching device for the resonant inverter, a damped oscillating noise is appeared at specific frequency band. This damped Oscillation is caused by the series and parallel resonance due to distributed circuit parameter of snubber and main circuit. This paper describes the frequency-impedance characteristic of the resonant inverter and optimal snubber design strategy to reduce the RF noise.

• Transactions on Electrical and Electronic Materials
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• v.14 no.3
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• pp.116-120
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• 2013

This paper proposes a novel RF MEMS dc-contact switch with stiff membrane on a quartz substrate. The uniqueness of this work lies in the utilization of a seesaw mechanism to restore the movable part to its rest position. The switching action is done by using separate pull-down and pull-up electrodes, and hence operation of the switch does not rely on the elastic recovery force of the membrane. One of the main problems faced by electrostatically actuated MEMS switches is the high operational voltages, which results from bending of the membrane, due to internal stress gradient. This is resolved by using a stiff and thick membrane. This membrane consists of flexible meanders, for easy movement between the two states. The device operates with an actuation voltage of 6.43 V, an insertion loss of -0.047 dB and isolation of -51.82 dB at 2 GHz.

• Journal of Electrical Engineering and Technology
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• v.6 no.3
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• pp.408-413
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• 2011

In this paper, a real-coefficient approach to Adaptive Frequency Sampling (AFS) technique is developed for efficient equivalent circuit modeling of RF components. This proposed method is advantageous than the vector fitting technique and the conventional AFS method in terms of fewer samples leading to a lower order of a rational function on a given data and to a direct conversion to an equivalent circuit for PSPICE(Personal Simulation Program with Integrated Circuit Emphsis) simulation, respectively. To validate the proposed method, the distributed equivalent circuit of a presented multi-layered RF low-pass filter is obtained using the proposed real-coefficient AFS, and then comparisons with EM simulation and circuit simulation for the device under consideration are achieved.

• Proceedings of the KIEE Conference
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• 2002.07d
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• pp.2572-2573
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• 2002

RF용 칩 설계에 있어서, Transponder에서 사용되는 칩 전원은 Tranceiver로부터 방사되는 RF Power를 고효율 쇼트키 다이오드을 통하여 정류하여 칩 내부에 캐패시터에 저장하여 내부회로의 동작시 충분한 전류를 제공하게된다. 이 분야의 연구는 칩 정류 효율 향상이라는 목표로 고효율 다이오드개발 및 임피던스 매칭방법과 고효율의 안테나 개발과 더불어 활발한 연구가 계속되어져 왔다. 본 논문에서는 Transponder용 전압을 제공해주는 쇼트키다이오드 더블러(Doubler)의 내부노드에 모듈레이션(Modulation) 트랜지스터 및 Transponder로서의 입력버퍼를 설계함에 있어서, 입력버퍼의 입력으로서 안테나로부터 1차 정류된 전압을 사용할 수 있는 방안을 제시한다. 또한 이를 적용하여 개발된 RF ID(Identification Device)칩의 주파수에 따른 특성 및 결과를 고찰토록 한다.

• Proceedings of the IEEK Conference
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• 2007.07a
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• pp.153-154
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• 2007

In this paper, we propose context information communication system using RF module to prevent railway cross accident. Since the communication module transmits to the train with high bit rate, OFDM(Orthogonal frequency division multiplexing) modulation method that distributes high speed data and transmits multiple times is applied. And image information is transmitted to the train's transceiver device by using ISM band (2.4GHz frequency band) that is proper to mobile communication. By using this system, we can deal with urgent situations at the railway cross and prevent railway cross accidents in advance.

• Proceedings of the KIPE Conference
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• 2019.07a
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• pp.358-359
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• 2019

철교나 석유비축기지 탱크저판 및 각종 매설관로 등 대부분 철 성분 골조는 시간이 경과하면 주변의 환경에 따라 부식이 급격히 일어난다. 이러한 철강재가 부식되는 철강재가 시설물의 주요 구성물이 되고 있는 시설물의 수명을 크게 단축시키는 주요원인이 되고 있다. 이에 대한 대비책으로 방청도료나 코팅을 이용하는 방법과 달리, 전기적으로 전위차를 같게 하여 부식을 방지하는 전기방식법을 적용함에 있어 방식전류가 불균일한 경우 양극 소모가 불균일함에 따라 교체시기 문제를 극복하기 위해 회로 등가 임피던스 추정 및 RF 릴레이 장착한 TB를 이용한 방식전류제어장치를 개발하였다.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.46 no.1
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• pp.94-101
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• 2009

This paper presents scalable modeling of spiral inductors for RFIC design based on $0.13{\mu}m$ RF CMOS process. For scalable modeling, several inductor patterns are designed and fabricated with variations of width, number of turns and inner radius. Feeding structures are optimized for accurate de-embedding of pad effects. After measuring the S parameters of the fabricated patterns, double-$\pi$ equivalent circuit parameters are extracted for each device and their geometrical dependences are modeled as scalable functions. The inductor library provides two types of models including standard and symmetric inductors. Standard and symmetric inductors have the range of $0.12{\sim}10.7nH$ and $0.08{\sim}13.6nH$ respectively. The models are valid up to 30GHz or self-resonance frequency. Through this research, a scalable inductor library with an error rate below 10% is developed for $0.13{\mu}m$ RF CMOS process.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.46 no.9
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• pp.68-73
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• 2009

This paper presents an easily modifiable structure of a serial peripheral interface (SPI) that is suitable for efficient testing of CMOS RF integrated circuits. The proposed SPI Is designed so that the address size and the accompanying software can be easily adjusted and modified according to the requirements and complexity of RF IC's under development. The hardware architecture and software algorithm to achieve the flexibility are described. The proposed SPI is fabricated in $0.13{\mu}m$ CMOS and successfully verified experimentally with a 2.7GHz fractional-N delta-sigma frequency synthesizer as a device under test.