• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.18 no.4
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• pp.309-312
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• 2005

The RFID tag IC has been presently abstracting great attention in the world because it can be one of the important sensor elements in the ubiquitous sense network in the future. The 125 kHz and 13.56 MHz RFID tag IC's have already been developed and now widely used in the world and the UHF band tag IC is under development. Domestically, the development of the 125 kHz tag IC was reported before, but there has been no report about the development of the 13.56 MHz tag IC up to now. In this paper, the results of the design, fabrication and measurement of a 13.56 MHz tag IC are discussed. The digital and the analog circuits for the chip were designed and the chip was fabricated using 0.35 ㎛ standard CMOS technology and measured with a separately prepared reader. It was found from the measurement results that it operated properly within 8 cm range of the reader.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.24 no.12
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• pp.1148-1157
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• 2013

In a passive UHF RFID system, the impedance matching between tag antenna and chip as well as the protocol parameter settings in a reader plays important role in determination of the maximum read-range. Almost no paper, however, has dealt with the above issues in relation with the maximum read range. In this paper, two known methods (of using the value from data sheets and proprietary RFID tester) and our proposing method in chip impedance evaluation are compared in terms of maximum read range. The read range of tags whose antenna impedance is conjugate matched with the chip impedance obtained from the proposed method is improved maximum 73 % more than that of tags from the other methods.

• Proceedings of the KWS Conference
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• 2007.11a
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• pp.223-226
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• 2007

본 연구에서는 Ag anisotropic conductive adhesive(ACA)의 종류, 경화 조건 및 안테나 패턴의 재질에 따른 flip chip bonding된 RFID die의 접합부 신뢰성이 조사되었다. 접합강도 측정에 의하여 접합강도가 최적화되는 공정 시간을 결정할 수 있었으며, 그러한 최적의 공정조건에서는 paste-type Ag ink로 인쇄된 안테나 상에서의 RFID die의 접합강도가 Cu 재질 안테나에 비해 상대적으로 높게 측정됨을 알 수 있었다. RFID tag의 인식거리 측정 시험을 통하여 적절한 경화 조건이 적용된다면 안테나의 재질이 인식거리 변화에 가장 주요한 영향을 미치는 인자임을 알 수 있었다. 아울러 Cu 안테나 패턴은 RFID die의 접합 과정에서 곡률을 가지며 휘어지면서 인식거리와 관련된 long-tem reliability를 악화시킬 수 있음을 관찰할 수 있었다.

• Journal of Navigation and Port Research
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• v.33 no.1
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• pp.51-56
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• 2009

This paper presents the design of high sensitive/broadband tag antenna for Radio Frequency Identification (RFID) in Ultra High Frequency(UHF) band. A proposed tag antenna size is $60\;mm\;{\times}\;10\;mm\;{\times}\;1\;mm$. The resonant frequency is 910MHz and bandwidth is about 900 MHz at -10 dB below. The measured return loss and directional pattern have been confirmed a good agreement with the calculation results. The read range of proposed tag antenna with chip is observed about 6.5 m and proposed tag antenna has been observed an average 0.5 m for more than read range of the commercial tag antenna.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.20 no.2
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• pp.154-160
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• 2009

This paper describes a wide bandwidth RFID tag antenna design for protection of connection part between chip and antenna. A proposed tag antenna size, a resonant frequency and bandwidth are $53{\times}10{\times}1\;mm$, 900 MHz and 800 MHz($500{\sim}1,300\;MHz$) at -10 dB below, respectively. The dielectric materials with different relative permittivity such as polyethylene, glass and silicon were applied for protection of connection part between the proposed antenna and chip on the way of whole and partial housing. The measured return loss and radiation pattern agreed well with the calculation results. The read range of the proposed tag antenna without any housing and of tag antenna with housing covered over all by silicon with 3 mm thickness were observed about 5 m and 4 m, respectively.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.29 no.2
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• pp.93-98
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• 2018

This paper introduces the development of HF(NFC) and UHF band(13.56 MHz, 920 MHz) tag antennas, imbedded in a box. In dual band antennas, the HF band tag can be used to inspect the box using NFC, and the UHF band tag can be used for logistics. The dielectric constant of the box material is measured and used for simulation. The Ntag213 chip manufactured by NXP is used in HF loop antennas, since NFC is possible with Ntag213. For the UHF band, the Higgs-3 chip manufactured by Alien is used. The HF tag antenna is located at the center of the UHF tag antenna, and the location of the HF tag antenna is calculated while considering coupling effects. The designed tag can be used by both the bands for the purposes of logistics and authentication.

• Journal of Korean Society for Geospatial Information Science
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• v.16 no.3
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• pp.43-49
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• 2008

The Real Time Location System (RTLS) is very important in the ubiquitous society for real time tracking of men, high price assets, and logistics products. In this work, we developed an active RF system for RTLS and tested its performance. The RTLS system developed in this work was constructed of three active readers and one active tag. The small size tag developed in this work operated with a coin type battery. To make the tag smaller, we used an internal PCB antenna and a chip antenna. We tested the performance of the tag. To reduce the manufacturing cost of our RF system, we used low price RF transceiver CC2510 chip-set. The CC2510 chip-set provided RSSI(Received Signal Strength Indicator) signal which could be used to determine the distances between an active tag and three active readers.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.45 no.12
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• pp.47-56
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• 2008

An RFID system comprises a reader and a tag, and this paper focuses on a tag design. A UHF tag is activated by energy supply using electromagnetic waves and energy reflection through impedance mismatching. The tag uses a $0.25{\mu}m$ CMOS process and comprises a digital part executing tag protocols, a 512-bit memory, and an analog part having a rectifier, a modulation/demodulation unit, a clock generator, etc. The total dimension of the tag, including a saw line, is $750{\mu}m*750{\mu}m$ and the power consumption of the tag consumption power is about $17.8{\mu}W$ at a supply voltage of 2V.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.44 no.1
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• pp.68-75
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• 2007

A single chip NFC transceiver supporting not only NFC active and passive mode but also 13.56MHz RFID reader and tag mode was designed and fabricated. The proposed NFC transceiver can operate as a RFID tag even without external power supply which has dual antenna structure for initiator and target. The area increment due to additional target antenna is negligible because the target antenna is constructed by using a shielding layer of initiator antenna. The analog front end circuit of the proposed NFC transceiver consists of a transmitter and receiver of reader/writer block supporting NFC initiator or RFID reader mode, and a tag circuit for target of passive NFC mode or RFID tag mode. The maximum baud rate of the proposed NFC device is 212kbps by using UART serial interface. The chip has been designed and fabricated using a Magnachip's $0.35{\mu}m$ double poly 4-metal CMOS process, and the effective area of the chip is 2200um by 3600um.

• Journal of electromagnetic engineering and science
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• v.13 no.4
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• pp.208-213
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• 2013

This paper proposes a tag antenna for radio frequency identification (RFID) food system. The RFID tag antenna is designed and fabricated based on the rectangular loop concept used in the UHF band (Korean and Japanese standards, 916.7-923.5MHz). The proposed tag antenna is composed of a radiation patch, sensor tag chip, temperature sensor, oscillator, and battery. We conjugated matching between the tag antenna and the sensor tag using a U-shaped stub. Details of the proposed tag antenna design and the simulated and measured results are presented and discussed.