• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2017.10a
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• pp.59-60
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• 2017

In this paper, we studied a design method for obtaining broadband property by loading a chip capacitor on a coplanar waveguide(CPW)-fed compact quasi-Yagi antenna(QYA). The proposed antenna is a three-element QYA with dipole, reflector, and director. To reduce the size, the ends of both dipole and reflector are bent, and balun is incorporated in the antenna. To improve impedance matching, the loading position and capacitance value of chip capacitor were determined. From some simulations, the proposed antenna using an FR4 substrate with a size of 90 mm by 90 mm was designed for the operation in a broadband covering the UHF RFID and GPS systems. The antenna showed a good performance with a broadband of 850-1,626 MHz(62.7%) for a VSWR ${\leq}2$, a gain ${\geq}3dBi$, and a frong-to-back ratio ${\geq}4.6dB$.

• Proceedings of the Korean Institute of Communication Sciences Conference
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• 2006.07a
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• pp.255-255
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• 2006

• Proceedings of the Korean Institute of Communication Sciences Conference
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• 2006.07a
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• pp.257-257
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• 2006

• Proceedings of the Korean Institute of Communication Sciences Conference
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• 2006.07a
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• pp.695-695
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• 2006

• Proceedings of the Korean Institute of Communication Sciences Conference
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• 2006.07a
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• pp.722-722
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• 2006

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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• 2009.04a
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• pp.55-57
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• 2009

This research was supported by agrant (07KLSGC02) from Cutting-edge Urban Development - Korean Land Spatialization Research Project funded by Ministry of Land, Transport and Maritime Affairs.

• Proceedings of the IEEK Conference
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• 2006.06a
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• pp.191-192
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• 2006

An orthogonal antenna is presented for reader applications of radio frequency identification (RFID) at 433 MHz. The antenna is composed of two $1{\times}2$ sub-arrays orthogonally placed on a ground plane. Two different feeding networks are introduced to control horizontal and vertical radiation current flows for each sub-array, respectively. An inverted-F structure is used as a radiation element with vertical and horizontal currents flowing on the radiator, thereby obtaining two linear polarizations. Antenna gains are 3.71 and 3.43 dBi and isolation between the two input ports is less than 25dB.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.31 no.11A
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• pp.1130-1137
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• 2006

One of the important performance issues in large-scale RFID systems is to resolve collisions among responses from RFID tags. Considering two do facto anti-collision solutions, namely the binary-tree splitting algorithm and the Slotted-Aloha algorithm, we propose to use multi-packet reception (MPR) capability to enhance the RFID tag reading rate (i.e., throughput). MPR allows an RFID reader to receive multiple reponses transmitted by tags at the same time. We analyze the effect of MPR capability in the above anti-collision algorithms, which is also validated by simulation. The analysis and simulation results show that RFID reader antenna design and signal separation techniques play an important role in improving RFID system performance with MPR capability.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.36 no.5A
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• pp.543-550
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• 2011

In order to improve readability, a leakage-signal canceller has been proposed in UHF-band RFID readers. The proposed canceller is composed of two blocks: an environment monitoring block for detection of Tx and RX power levels and a leakage cancellation block. The leakage canceller consists of directional-couplers, digital attenuators and phase shifters based on the feed-forward scheme. The leakage canceller is located between antenna and reader. An improved experimental characterization of the scheme is presented with results from the reader operating in the Korean RFID frequency band, conforming the validity of the approach with more than 29 dB of leakage cancellation.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.34 no.12B
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• pp.1524-1534
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• 2009

In recent, diagnosing and monitoring technology via in vivo information has been evolved rapidly in worldwide with such capsule-kinds means of incorporating an RFID tag as wireless communication tool. Thus circumstance is pressing local body in Korea to research and develop ingestible RFID capsule which has more miniaturized form, less low power, harmless. This paper focused to investigate new technology and patents, R&D information for adopting proper frequency and designing wireless ingestible capsule antenna system, and suggested practical assignments to implement local R&D. Descriptions are consist of introduction, technology outline, tendency for R&D, patent, market, conclusion and suggestion.