• Journal of the Korea Institute of Information and Communication Engineering
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• v.14 no.1
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• pp.23-30
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• 2010

In this paper, a design for the 900MHz bandwidth RFID reader antenna with circular polarization is proposed and experimentally investigated. The 900MHz bandwidth RFID reader antenna is proposed as a simple radiator with loading capacitor to generate LHCP(Left Hand Circular Polarization). Also, the design and fabrication of antenna has the returnloss of -32.28dB at the center frequency of 1010MHz and Bandwidth of 12.5% at 905Hz~1030MHz. Proposed LHCP antenna of maximum gain is 6dBi and satisfy axial ratio based on 2. From the measured result, axial ratios based on 2 are observed at the operating frequencies. The proposed antenna is suitable for RFID applications in wireless communications.

• Journal of the Microelectronics and Packaging Society
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• v.1 no.2
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• pp.143-146
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• 1994

본 연구에서는 900MHz PLL Module을 설계제조하였다. 제안된 PLL Module은 900MHz VCO 및 PLL Controller로 구성되었다. PLL Module의 출력레벨은 -2dBm이었다.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.14 no.8
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• pp.1943-1949
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• 2010

In this paper, we developed a RFID tag antenna using one-sheet inlay pattern which consist of two different frequencies in one layer. The antenna in one-sheet inlay RFID tag does not use different kind RFID antennas in a card but implement 13.56MHz and 900MHz RFID tag antennas in one sheet. In order to evaluate the usability of proposed method, we configured test equipments and designed 6 different patterns and test the recognition distance of each pattern. Among the one-sheet inlay RFID tag antenna designs, the pattern no.5 has good performance with recognition distance of 5.34m at 900MHz and 3.5m at 13.56MHz.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.11 no.6
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• pp.893-899
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• 2000

A 900 MHz low-noise amplifier(LNA) with a measured noise figure of 4.8 dB and an associated gain of 13.2 dB was fabricated in a 0.65 $\mu$m CMOS. The inductive source architecture of offers the possibility of achieving the best noise performance. At 900 MHz, the fabricated LNA dissipates 39 mW from a single 3 V power supply including the bias circuitry and provides -26dB input return loss, -17 dB output return loss, and an input 1-dB compression level of -12 dBm.

• The Proceeding of the Korean Institute of Electromagnetic Engineering and Science
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• v.16 no.3 s.55
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• pp.3-15
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• 2005

본 고에서는 최근 많은 관심을 갖고 있는 900 MHz UHF 대역을 사용하는 RFID시스템의 무선 인터페이스 표준에 대해 살펴본다 900 MHz UHF 대역의 RFID시스템은 유통,물류에 사용될 것으로 기대되기 때문에 국제표준화기구인 ISO와 국제 민간표준화 기구인 EPCglobal에서 무선 인터페이스 표준을 세우고 있다. 특히 2004년부터 이뤄진 EPCglobal의 EPC Class 1 Generation 2표준은 향후 ISO의 900 MHz 대역 RFID 시스템의 새로운 무선 인터페이스 표준으로 정해질 것으로 기대되고 있어 더욱 관심을 모으고 있다. 이에 본 고에서는 900 MHz대역 RFID 무선 인터페이스 표준인 ISO/IEC의 ISO 18000-6과 EPCglobal의 EPC Class 1 Generation 1, Generation 2 를 중심으로 900 MHz대역 RFID 시스템의 무선 인터페이스 표준화 동향을 살펴보았다.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2008.05a
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• pp.125-128
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• 2008

In this paper, a stand-type planar antenna of 900MHz RFID band is designed and fabricated. As the proposed antenna is stand-type use of air permittivity, Bandwidth used ground height at rectangle patch structure and coaxial feed line is widen. Also wideband width can solve problem that RFID tag attached to things happens frequency shift keying phenomenon by liquid, special metal, temperature, humidity etc. Bandwidth of fabricated antenna to VSWR less than 2 is satisfied 11.9% at $890MHz{\sim}1000MHz$. And proposed antenna is circular polarization antenna of operating characteristics that axial ratio is less than 2 and gain is 6dBi.

• Journal of the Microelectronics and Packaging Society
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• v.6 no.3
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• pp.1-7
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• 1999

A single RF transceiver evaluation board have been developed for the purpose of application to the 900MHz band transceiver contained RF-IC chip And environment test was evaluated. The RF-IC chipset includes LNA(Low Noise Amplifier), down-conversion mixer, AGC(Automatic Gain Controller), switched capacitor filter and down sampling mixer. The RF evaluation board for the testing of chipset contained various external matching circuits, filters such as RF/IF SAW(Surface Acoustic Wave) filter and duplexer and power supply circuits. With the range of 2.7~3.3V the operated chip revealed moderate power consumption of 42mA. The chip was well operated at the receiving frequency of 925~960MHz. Measurement result is similar to general RF receiving specification of the 900MHz digital mobile phone.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.8 no.6
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• pp.665-680
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• 1997

The specific absorption rate (SAR) distributions in various models of the human head have been analyzed when the models are exposed to 350 MHz and 900 MHz plane waves. The numerical analysis is performed with the finite-difference time-domain (FDTD) method. A homogeneous sphere including a cylinderical neck, a homogeneous head shaped model, and a heterogeneous realistic model are used as models of human head. The incident plane wave used for these calculations is propagating from the front to the back or from the back to the front of the head model, with its E-field vector orientation being parallel to the major length of the body. The specific findings are: 1) the average SARs of the three models are similar mutually but the local SARs of them differ greatly mutually; 2) the power is deposed more deeply in the head at 350 MHz, which is roughly the resonant frequency of a human head, than at 900 MHz; 3) for a plane wave propagating from the back, "hot spot" is found in the neck region, not in the head; 4) for a plane wave propagating from the front, "hot spot" is found in the nose at 900 MHz, and in the upper part of the lip and the jaw region at 350 MHz.

• Proceedings of the Korean Information Science Society Conference
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• 2007.10d
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• pp.290-293
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• 2007

RFID 시스템은 주파수마다 다른 인식 거리를 가지며, 장거리 시스템의 900MHz의 경우 1m에서 최대 10m까지 인식 범위를 가진다. 주파수는 거리에 의하여 해당 파장이 감쇠하는 현상이 생하며, PSK 질문기에서 발생하는 전파는 1/4파장 변화에 의하여 출력 신호 극성이 반전되며 허용 인식범위 내 응답기에서도 적합한 통신이 안되는 영역이 발생하였다. 본 연구에서는 900MHz RFID 장비를 기본으로 안테나와 태그의 위치를 변경하여 테스트를 진행하여 어떤 지정에서 음영구역이 발생하는지 테스트를 진행하고, 문제점이 발생하는 원인에 대하여 논하며 이런 문제점을 해결하기 위하여 일본에서 2.4GHz RFID 응답기에서 사용하는 베이스 밴드 FSK 변조회로를 기반한 900MHz RFID 응답기 설계방안을 제안한다.

• Proceedings of the KIEE Conference
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• 2006.10a
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• pp.141-142
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• 2006

본 논문에서는 단일 FET를 이용하여 900MHz/2.14GHz 이중 대역 고효율 도허티 전력증폭기 설계 구현을 하였다. 이중대역 도허티 전격증폭기의 출력전력은 900MHz 에서 35.91dBm, 2.14GHz에서 35.91 dBm의 출력을 얻었으며, 전력부가효율은 900MHz에서 40.32%, 2.14GHz에서는 40.47%의 효율을 획득 하였다. 또한 본 논문에서 단 하나의 능등소자를 이용하여 최대한의 출력전력을 얻기 위하여 최대 전력정합법을 사용하였으며 그 결과 이중대역 전력증폭기를 구현할 수 있었다.