• Proceedings of the IEEK Conference
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• 2000.06e
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• pp.203-206
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• 2000

Depending upon the existence of the battery, transponder is divided into active and passive transponder. The passive transponder operates without the inner battery and so has no limitation in its operating range and life time. But the power consumption in the smartcard should be low. In this paper, the analysis and design of the passive smartcard system oerated at 125kHz is presented and is confirmed by simulation and experiment.

• Proceedings of the KAIS Fall Conference
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• 2010.05a
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• pp.357-359
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• 2010

본 논문에서는 논리 설계를 위해서 I-ROB 3000이라는 로봇 키트를 사용하여 논리 설계를 검증하였다. 이 검증에는 iRoV-Lab 3000의 장착된 로봇 모듈인 FPA 모듈,Stepper Motor 모듈,적외선 송수신센서 모듈, 카메라 모듈,RF 모듈 LED,TEXT LCD, 7-segment를 제어하기 위한 FPGA를 사용하며,FPGA설계를 위해 Schematic Design 또는HDL에 대해 연구한다.로봇 설계 시스템의 내부구조를 이해하고 개발환경을 구축할수 있다. 로봇의 구성요소와 각각의 구성요소(Sensor 모듈,display 모듈, Stepper Motor 모듈,RF 모듈)의 동작 원리를 개발한다.

• Proceedings of the KAIS Fall Conference
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• 2010.05a
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• pp.360-362
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• 2010

본 논문에서는 SoC 키트에 해당하는 iRoV-Lab 3000의 장착된 로봇 모듈인 FPA 모듈, Stepper Motor 모듈, 적외선 송수신 센서 모듈, 카메라 모듈, RF 모듈 LED, TEXT LCD, 7-segment를 제어하기 위한 FPGA를 사용하며, FPGA설계를 위해 Schematic Design 또는 HDL에 대해 연구한다. FPGA의 내부구조를 이해하고 개발환경을 구축할 수 있다. 로봇의 구성요소와 각각의 구성요소(Sensor 모듈, display 모듈, Stepper Motor 모듈, RF 모듈)의 동작 원리를 개발한다.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.30 no.11A
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• pp.1104-1109
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• 2005

In this paper, a Ka-band harmonic mixer is designed and fabricated on the base of the multiplier theory that there is a bias point to maximize the third harmonic order($3f_{LO}$) with respect to a fundamental LO frequency($f_{LO}$), which can make the high-order mixing element($f_{RF}{\pm}3f_{LO}$) to be greater than other mixing elements, Pumping a RF frequency($f_{RF}$) and LO frequency($f_{LO}$). The harmonic mixer by the proposed design method is fabricated by using a commercial GaAs MESFET device with a plastic package and overcome these disadvantages that a conventional mixer in Ka-band suffer from a high cost, inefficient productivity and circuit complexity. The harmonic mixer have a -10 dB conversion loss at the IF Sequency($3f_{LO}-f_{RF}$=1.0GHz) by selecting a gate bias voltage for the maximum third-order LO harmonic element($3f_{LO}$=34.5 GHz) as pumping LO frequency($f_{LO}$=11.5 GHz) With respect to RF Sequency ($f_{RF}$=33.5GHz)

• ETRI Journal
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• v.29 no.3
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• pp.371-380
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• 2007

This paper proposes a new automatic compensation network (ACN) for a system-on-chip (SoC) transceiver. We built a 5 GHz low noise amplifier (LNA) with an on-chip ACN using 0.18 ${\mu}m$ SiGe technology. This network is extremely useful for today's radio frequency (RF) integrated circuit devices in a complete RF transceiver environment. The network comprises an RF design-for-testability (DFT) circuit, capacitor mirror banks, and a digital signal processor. The RF DFT circuit consists of a test amplifier and RF peak detectors. The RF DFT circuit helps the network to provide DC output voltages, which makes the compensation network automatic. The proposed technique utilizes output DC voltage measurements and these measured values are translated into the LNA specifications such as input impedance, gain, and noise figure using the developed mathematical equations. The ACN automatically adjusts the performance of the 5 GHz LNA with the processor in the SoC transceiver when the LNA goes out of the normal range of operation. The ACN compensates abnormal operation due to unusual thermal variation or unusual process variation. The ACN is simple, inexpensive and suitable for a complete RF transceiver environment.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.11 no.3
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• pp.1-8
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• 2011

In this paper, data transmission corrugated horn antenna for RF sensor satellite system and its radiation characteristic are presented. The proposed antenna is designed, fabricated and measured to obtain the maximum gain at ${\pm}60^{\circ}$ of its radiation patterns. The result of the proposed antenna is that the return loss is less than -15 dB and the gain is over 5 dBi at ${\pm}60^{\circ}$ of its radiation patterns. From these results, it is confirmed that the proposed can be used as data transmission corrugated horn antenna for RF sensor satellite system.

• Journal of electromagnetic engineering and science
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• v.3 no.1
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• pp.1-6
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• 2003

In this paper, a sub-harmonic dual-gate FET mixer is suggested to improve the isolation characteristic between LO and RF ports of an unbalanced mixer. The mixer was designed by using single-gate FET cascode structure and driven by the second harmonic component of LO signal. A dual-gate FET mixer has good isolation characteristic since RF and LO signals are injected into gatel and gate2, respectively. In addition, the isolation characteristic of a sub-harmonic mixer is better than that of a fundamental mixer due to the large frequency separation between the LO and RF frequencies. As RF power was -30 ㏈m and LO power was 0 ㏈m, the designed mixer yielded the -47.17 ㏈m LO-to-RF leakage power level, 10 ㏈ conversion gain, -2.5 ㏈m OIP3, -12.5 ㏈m IIP3 and -1 ㏈m 1 ㏈ gain compression point. Since the LO-to-RF leakage power level of the designed mixer is as good as that of a double-balanced mixer, the sub-harmonic dual-gate FET mixer can be utilized instead.

• 한국정보통신설비학회:학술대회논문집
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• 2002.08a
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• pp.17-20
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• 2002

본 논문에서는 세라믹 칩 안테나를 LTCC로 구현하여 다중 대역 특성을 얻는 방법을 제안하고 있다. 휴대용 단말기에 칩 안테나를 내장함으로 물리적 손상을 피하고 위치추적 시스템(GPS) 대역과 단말기 송수신용 대역, 즉 두 대역 이상 사용 가능하고 ${\varepsilon}_r=7.8$인 세라믹 칩 안테나를 LTCC(Low Temperature Co-fired Ceramic)공정을 이용하여 세라믹 칩 내부에 정합 회로를 구현하여 이중 대역 특성을 갖는 구조에 대해 논의하고 있다. 안테나의 전체 크기는 $16mm{\times}4mm{\times}2mm$ 이며 대역폭은 삽입손실 -10dB 기준 대략 1560MHz에서 2160MHz까지 약 600MHz정도이다. 측정은 접지면의 넓이가50mmx50mm이고 두께=0.7874mm, ${\varepsilon}_r=4.6$인 FR4 기판을 이용하여 측정한다.

• Journal of IKEEE
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• v.19 no.3
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• pp.371-377
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• 2015

This paper is about the RF transceiver designed and implementation for common data link. The trasmitter is configured as a frequency up-converter, a power amplifier and a duplexer. The receiver is configured as a duplxer, a frequency down-converter and a low noise amplifier. The maximum transmission distance, the reception sensitivity is designed to meet the electrical and temperature characteristics and the like. Using a modeling and simulation in order to meet the requirements of the RF transceiver has been designed and implemented. Transmitting output power and Noise Figure has been measured with 38.58dBm and 5.5dB, respectively. All of the electrical and temperature specifications was meet. Was confirmed all of the requirement specification by electrical characteristics test and temperature characteristics test.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.26 no.11
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• pp.978-984
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• 2015

In this paper, we designed a RF transceiver operating up to 200 km operating range and 45 Mbps data rate. The RF transceiver operates in Ku band and composed of up/down converter, high power amplifier, front-end elements. To satisfy the operating range of RF transceiver, 10W power amplifier was required and realized by using GaN power amplifier. Moreover, to mitigate mutual interference for different bandwidth signals due to the adaptive transmission speed control function, SAW filter bank structure was used. To verify system requirement satisfaction AWR simulation tool was used.