• Journal of Advanced Navigation Technology
• /
• v.14 no.2
• /
• pp.170-175
• /
• 2010

This article proposed polarization selective antenna for UHF RFID system. The proposed antenna is consist of microstrip patch antenna with dual feeding and two SPDT switches and a SP4T switch and 3dB hybrid coupler. Through control of voltage of switches, the proposed reader antenna can select horizontally linear polarization, vertically linear polarization, left-hand circular polarization (LHCP) and right hand circular polarization (RHCP). The proposed reader antenna satisfied 2:1 VSWR at 902MHz ~ 928MHz. and 3dB under AR(axial ratio). And it can select appropriative polarization with user environment and tag polarization. So it minimize PLF and increased reading distance.

• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.63 no.1
• /
• pp.63-69
• /
• 2014

RFIDs have not become widespread as expected partly due to the cost, size, read range, and reliability problems of tags. The success rate of reading must be improved in order for RFIDs to be widely adopted. Quality control of tags is crucial to meet this requirement. In this study, we designed and implemented a high-performance reader used in inspection equipment that conducts prior inspection of tags. To improve performance of the developed reader, the baseband modem and command processor (CP) were designed using H/W logic and implemented with FPGA. The inspection of small pitch inlays was made possible through the antenna shielding device and H/W command processor function. This equipment enables accurate evaluation of performance and identification of tags satisfying a given read range. By contributing to sort out defective tags, the results can ultimately lead to more stable RFID services.

• Proceedings of the Korea Electromagnetic Engineering Society Conference
• /
• 2005.11a
• /
• pp.231-234
• /
• 2005

In this paper, Dual-polarized Tx/Rx antenna for RFID reader is designed and fabricated to apply to RFID reader. Each feeding network of Tx/Rx is designed to improve the port-isolation and cross-polarization, and sequential rotation feeding scheme has been applied to increase of axial ratio bandwidth. Measured results show that 2.35dBi of antenna gain in 900MHz$\sim$928MHz, 150MHz of 3dB axial ratio bandwidth, -38dB$\sim$-40dB of port-isolation, and -30dB$\sim$-40dB of cross-polarization.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.38C no.10
• /
• pp.841-851
• /
• 2013

Mobile RFID/NFC linkage technology means a provision of integrated 2 existing mobile RFID services by developing the 900MHz mobile RFID reader and the NFC reader/tag into one SoC to be put on a USIM card. In this paper, the mobile RFID related technologies that offer similar services as NFC were also analyzed to understand the potential linkage to NFC and the requirements for the linkage. In addition, the introduction of dual tag and the code system linkage suggested a linking method to maximally use the existing infrastructure and the requirement satisfaction was analyzed. Lastly, based on the analysis, the future direction for the new standard design was suggested.

• 한국정보통신설비학회:학술대회논문집
• /
• 2007.08a
• /
• pp.147-150
• /
• 2007

This paper presents an advanced RFID reader system implementing multi-protocols and multi-standards at 900MHz. In accordance with the strict regulations specified by ISO 18000-6 B-Type and EPC Global Gen 2, we have designed corresponding systemic factors which meet the domestic radio frequency utilizing bands of 910-914MHz. In addition, we develop numerous crucial factors of system compatibility options including SSB (Single-Side Band) and DSB (Double-Side Band) specifications, also OOK (On-Off Keying), ASK (Amplitude Shift Keying) and PR-ASK (Phase Reversed-Amplitude Shift Keying) modulation formula. Remarkable technical features of system in this paper can be the direct conversion routines using I/Q Modulation/Demodulation respectively, and Full-Duplex formulation operating at identical frequency bands.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.16 no.12 s.103
• /
• pp.1213-1221
• /
• 2005

In this paper, dual-polarized antenna for UHF RFID reader has been described. Feeding network and antenna structure have been designed, such that both port isolation between transmitting and receiving port and cross-polarization be maximized, and overall antenna size be minimized as well. In addition, sequentially rotated feeding scheme has been adopted to secure axial ratio bandwidth in the circular polarization. Test results show 2.35 dBi antenna gain in 900 to 928 MHz frequency range and 150 MHz axial ratio bandwidth, respectively. And, the proposed antenna has a port isolation of -40 to -38 dB and a cross-polarization of -40 to -30 dB.

• The Journal of The Korea Institute of Intelligent Transport Systems
• /
• v.11 no.4
• /
• pp.80-85
• /
• 2012

In this paper, a new planar folded UHF band RFID reader antenna is suggested. For the antenna suggested in this paper, 4 PIFA (Planar Inverted F Antenna) micro-strip structures are adopted. The size is $50mm{\times}50mm{\times}6.2mm$. The gain of the antenna is 1.1 dBi, the VSWR is 1.2:1, and the efficiency is 63.3 %. The radiation pattern is designed as upper direction. Identification distance for the RFID tags is improved by minimizing hand effects with properly integrating 4 PIFAs.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.39C no.12
• /
• pp.1225-1229
• /
• 2014

This paper introduces a development of the auto sushi conveyer-belt payment system using UHF RFID dishes. In a sushi bar, instead of counting the number of the finished sushi dishes, sushi dishes with the UHF RFID have been used in the auto payment system to have accuracy and convenience. To recognize each dish, the UHF RFID tag has been designed, and auto-payment system has been developed. The UHF RFID tag under the dish has been recognized by an RFID reader, and the auto RFID payment system shows the total price of the finished dishes based on the color and number of dishes automatically. The performance of the developed UHF RFID tag and auto RFID payment system have been measured and verified.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.16 no.5 s.96
• /
• pp.472-481
• /
• 2005

This paper reports the design of RFID reader antennas working in UHF band. The reader antennas were designed using a Pareto Genetic Algorithm(Pareto GA). Antennas were optimized to have circular polarization(CP) with less than 3 dB axial ratio, impedance matching with less than VSWR=2 within the frequency range of UHF, an adequate readable range, a restricted size(kr<2.22) considering the practical condition. After Pareto GA optimization, we selected and built the most suitable antenna design and compared the measured results to the simulations. Operating principle of the antenna was explained by investigating the amplitude and the phase of the induced current on the antenna body. We also researched the stability of the antenna with respect to the manufacturing error and studied the critical design parameters by applying the random error method on the antenna bent points.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.23 no.1
• /
• pp.131-134
• /
• 2012

A bar-code shape UHF RFID tag antenna is designed and fabricated with silver conductive ink. It can be recognize by both bar-code scanner and RFID reader. The bar-code shape is taken from a general box of a product, and the product code of the bar-code is used for the antenna design. The tag antenna is fabricated with silver conductive ink using a T-matching structure. The designed tag antenna is satisfied with bar-code system and RFID system simultaneously. The input reflection coefficient characteristics and the reading range pattern are measured. The peak reading range is about 111 cm, which is long enough.