• The Journal of the Korea Contents Association
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• v.15 no.8
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• pp.9-17
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• 2015

One of RFID features is that each RFID tag has a unique identifying code. Logistic System utilizes RFID tag as location tracing, understanding stock or etc. On the other hand, there is a problem of overall lower recognition rate by getting the information of non-mobility tags with no need for reading. To solve this problem, we trace and analyze variation of moving and moveless RFID tag sensitivity by the hour. In analyzed data, we verify that tag sensitivity of mobile RFID is gradually increase while non-mobility tag has same intensity value. In order to detect mobile tag, we generate a function using Matlab with analyzed data and separate moving tags from non-mobility tags by software. As a result, we can confirm that non-mobility tags are detected by software and recognition rate of RFID tag is improved by separating moveless tag.

• Journal of electromagnetic engineering and science
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• v.11 no.1
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• pp.1-4
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• 2011

In this letter, we propose a novel tag antenna that has low performance degradation with nearby dielectric material. We obtained a stable reading performance and a broad matching bandwidth on nearby dielectric materials by employing a T-matching network with thick line width and capacitively slot-loaded arms. We then built the proposed antenna and measured the tag sensitivity to examine the reading characteristics with nearby dielectric materials. The measured results clearly demonstrate stable tag sensitivity with various nearby dielectric materials, such as foam, acrylic-plastic, glass, and ceramic plates. To more closely observe the antenna characteristics with nearby dielectric materials, we also examined the impedance variation and surface current distribution with respect to the dielectric constant of nearby target objects, which ranged from $1{\times}{\varepsilon}_0$ to $16{\times}{\varepsilon}_0$.

• 한국정보통신설비학회:학술대회논문집
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• 2008.08a
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• pp.469-472
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• 2008

In this paper, we discuss the recent trends on the passive UHF RFID tag chip design techniques and several important system parameters. We also summarize link budget studies on both conventional and modem UHF RFID communications. The paper highlights the reverse link limited case, which has known to be the minor concern if reader continuous wave (CW) can reach the tag in sufficient level. This makes sense when the tag sensitivity is rather high (over 10-12${\mu}W$); however, since the tag chip fabrication technologies have been developed by time, the tag chip threshold levels are now less-dominant in determining link margin. If the tag limitation can be alleviated, the forward link limited case can be resolved; thus, we rather focus on the path-loss problem. Since the path-losses are still exist in both forward and reverse links, and it can be doubled while CW travels the reader-tag-reader path because forward link and reverse link are on the same distance. Consider if reader receiver sensitivity is very high in the worst case. In this case, weaken tag response (i.e., backscatters) cannot reach the level that reader receiver can process tag data; bit-error rate can be higher. Overall, backscatter levels should be high enough so that reader receiver can correctly function. After discussing link budget, we carried out practical measurements on fading effects between two circularly polarized UHF RFID antennas in a small scale area.

• Journal of Navigation and Port Research
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• v.32 no.10
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• pp.793-798
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• 2008

This paper presents a design of RFID(Radio Frequency Identification} tag antenna which has high sensitivity for car side mirror. A proposed tag antenna ($154\;mm{\times}66\;mm{\times}1;mm$) resonants at 900 MHz and has a wide bandwidth of 690 MHz($490\;MHz{\sim}1180\;MHz$). The measured gain and readable range of tag antenna are 5.8 dBd and 10 m, respectively. Radiation pattern and readable range of proposed tag antenna located on inside of a side mirror including a car body are measured at anechoic chamber. It has been confirmed that the readable range in the vicinity of $90^{\circ}$ has been expanded about 1.5 m by comparison with one of proposed tag antenna without of car body. Good performance of the proposed tag antenna was observed and proved by comparison of measured results of commercial tag antenna.

• Journal of the Institute of Electronics and Information Engineers
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• v.50 no.4
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• pp.203-211
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• 2013

UHF RFID tag designers usually ndde the chip impedance and read power sensitivity value obtained when a tag chip is mounted on a chip pad. The chip impedance, however, is not able to be supplied by chip manufacturer, since the chip impedance is varied according to tag designs and fabrication processes. Instead, the chip makers mostly supply the chip impedances measured on the bare dies. This study proposes a chip impedance and read power sensitivity evaluation method which requires a few simple auxiliary and some RF measuring equipment. As it is impractical to measure the chip impedance directly at mounted chip terminals, some form test fixture is employed and the effect of the fixture is modeled and de-embeded to determine the chip impedance and the read power sensitivity. Validity and accuracy of the proposed de-embed method are examined by using commercial RFID tag chips as well as a capacitor and a resistor the value of which are known.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.31 no.11A
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• pp.1159-1166
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• 2006

In this paper, we have designed a RFID reader receiver system for improving the performance of the passive Tag based 9$'908.5{\sim}914MHz'$ RFID reader, and analyzed the system performance according to the frequency, the reader, and tag properties. The commercial receive system causes a loss in sensitivity because of 24 capacitors and 6 inductors. So we have designed an improved system using a circulator, LNA and a SAW filter. The experimental results show that the use of a circulator to separate the Tx/Rx paths eliminates interference, the LNA improves the sensitivity of the Rx module and SAW filter eliminates the noise and spurious components in the received signal.

• 한국ITS학회:학술대회논문집
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• 2008.11a
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• pp.347-350
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• 2008

• The Journal of Korean Institute of Communications and Information Sciences
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• v.34 no.5A
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• pp.372-380
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• 2009

In this paper, we analyze the active RFID systems ISO/IEC 18000-7 and ISO/IEC 18000-4. In order to improve the coverage in sensor networks, which consist active RFID tag, we propose RFID multi-hop relay system using active RFID relay tag. To compare the performance between the existing ISO/IEC 18000-7 system and the proposed RFID multi-hop relay system, we introduce new system efficiency measure and sensitivity-based measure of achieved coverage. Also, we analyze the performance of the proposed system and compare it with that of the existing system through MCL (Minimum Coupling Loss) analysis and SLS (System Level Simulation) analysis.

• Proceedings of the Korea Information Processing Society Conference
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• 2007.05a
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• pp.1450-1452
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• 2007

RFID(Radio Frequency IDentification) 기술은 RF 신호를 사용하여 물품에 부착된 전자태그(electronic Tag)를 식별하는 비접촉식 기술로서 사물의 정보 및 주변 환경정보를 자동으로 추출하는 특성을 가지고 있다. RFID는 전자태그의 저가격과, 식별코드의 표준화에 힘입어 식료품으로부터 환경관리, 물류 유통 등의 모든 영역 적용에 가능하다. 그러나 현재 RFID 기술을 응용한 사례는 주로 대규모 산업 분야에서만 적용되어 있고, 작은 업체, 가정 등 소규모 그룹에서의 적용 사례는 드문 실정이다. 특히 스마트 홈을 지향하고 있는 가정에서는 각종 식료품, 옷, 책 등 다양한 가정용품들의 관리에 있어서 RFID를 활용은 필수불가결하다. 따라서 본 논문에서 가정 내에서 의류, 식료품, 서적 등 가정 내에 있는 모든 물품에 대해서 RFID 기술을 활용할 수 있도록, 가정 내 특징을 분석하고, 적용 환경에 따른 RFID 인식률 실험을 통하여, 가정 내의 최적의 RFID 시스템 구축 방향성을 제시한다.

• The Journal of the Korea institute of electronic communication sciences
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• v.9 no.10
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• pp.1145-1152
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• 2014

The RFID (Radio-Frequency Identification) system is a technology to discern things by radio and an epoch-making new method to improve product management such as distribution, transport, mobilization, inventory control. However, RFID, which uses radio, is at risk for information leakage and falsification due to the vulnerability of security of the communication section. We designed the new authentication protocol by applying the tent map, which is the representative complex systems, to the RFID communication system. A more solid and simple authentication system was designed by applying the initial value sensitivity and irregularity, which are the representative characteristics of the complex system, to the reader and tag of RFID. The purpose of this paper is to verify the usability of the RFID authentication protocol design that uses the nonlinear system shown in this thesis by the new system differentiated from the authentication system that depends on the existing hash function or random numbers.