• Journal of Navigation and Port Research
• /
• v.32 no.5
• /
• pp.363-368
• /
• 2008

This paper presents a miniaturization design technique of radio frequency identification (RFID) tag antenna operated in 910 MHz band. Miniaturization structure design for a tag antenna is performed by structure application of the folded dipole and meander line. In order to realize the maximum power transmission, imaginary part of a chip impedance and a tag antenna impedance is matched by complex conjugate number. The optimized tag antenna size is $50\;nm\;{\times}\;40\;nm\;{\times}\;1.6\;nm$ and its size is reduced about 62 % comparison with antenna size of reference [4]. The measured results of fabricated tag antenna are confirmed the reasonable agreement with prediction. The read range of the tag antenna with chip observed about 5 m.

• The KIPS Transactions:PartA
• /
• v.15A no.5
• /
• pp.287-294
• /
• 2008

A tag collision arbitration algorithm for RFID passive tags is one of the important issues for fast tag identification, since reader and tag have a shared wireless channel in RFID system. This paper suggests Hyper-Hybrid Query Tree algorithm to prevent the tag-collisions. The suggested algorithms determine the specified point in time for tag to transfer ID to reader by using value 1 of the upper 3 bit based on Query Tree. Also, because the transferred upper 3 bits of tag is different depending on the time of transfer, it is possible to predict in the suggested Algorithm. In the performance evaluation through simulation, it shows the suggested algorithm has higher performance in the number of queries compared to other Tree-based protocols.

• Journal of the Korea Society of Computer and Information
• /
• v.17 no.2
• /
• pp.207-214
• /
• 2012

This paper is to improve an identification ratio of tags by analyzing Slotted ALOHA, Dynamic Slotted ALOHA, Binary-tree and Query-tree and shortening the tag identification time in mobile RFID. Also, it enables the stable information transmission of tags by saving backscattering power of tags through shortening of identification time. As a result, this increases the available time of the battery and accessibility to a RFID service. For this, we proposed the energy-efficient tag anti-collision protocol for mobile RFID. The proposed scheme shows advanced result in identification time and collision counts. This scheme may be the first attempt for the mobile anti-collision.

• Journal of Biosystems Engineering
• /
• v.27 no.5
• /
• pp.459-466
• /
• 2002

In Korea, a need of automatic dairy farm management system has been increased to lower production cost and to strengthen international competition. However, the present management system was mostly relied on foreign technologies and caused some problems in post management and after-sales services. Therefore, though there is a problem of price and quality at present, domestic technologies of the management system should be developed for the long run. This study was conducted to develop an electronic identification unit for an automatic dairy farm management system. The developed system was consisted of a tag, a reader, a switching circuit, and a personal computer. The tag attachable to each individual cow was developed to transmit individual radio frequency(RF) code into the air with modulation of ASK(amplitude shift keying). And the switching circuit was added to avoid confusion on reception and transmittance. The reader attached to a feeding device was developed to transmit activating signal periodically and to identify code of the individual tag when the tag was approached to the device. The reader was consisted of an active filter, a detecter, a comparator and a microcontroller. The test result was feasible enough to apply it for the automatic farm management system and the identified maximum distance was about 37cm.

• Journal of the Korean Society for Railway
• /
• v.4 no.4
• /
• pp.155-161
• /
• 2001

In this paper, the method is suggested to prevent data collision or damage on RFID(Radio Frequency Identification) system, in case a reader reading multi-tag simultaneously, using binary-search algorithm and Time-domain anti-collision procedure at reader and tag, respectively. The RFID system is designed that Reader enable to communicate with Tag on 13.56MHz bandwidth which is ISM(Industrial Science Medical) bandwidth, antennas of Tag part are designed using MCRF335 Chip. When RF communication is achieved between reader and tag, in case that data is transmitted to reader pass through multiple tags simultaneously, a study on the anti-collision method for the situation that the data collision occurs is performed.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2005.10a
• /
• pp.892-896
• /
• 2005

This paper presents method of depriving the relationship between static passive RFID tag and mobile robot In the field of tag-range. We use probabilistic sensor model of RFID reader by experiments. And we proposed estimation techniques by using direction of identification and relative-distance from the sensor model. Corresponding to distribution of identification, we can correct estimated tag position in relative coordinate. Simulation and Experimental Results show that the proposed method can provide good performance and thus be used fer mobile-robot localization.

• Journal of Korea Society of Industrial Information Systems
• /
• v.20 no.2
• /
• pp.19-24
• /
• 2015

In this paper, a folded label type RFID tag antenna is designed and produecd for metellic environment over UHF band. Since performance of regular label type RFID tag is seriously degraded for the metallic environment, a folded label tag is proposed to improve the performance. The proposed tag is operating at 910MHz by using inductive T Matching Feed and simulated in HFSS by Ansoft. The actual size is $65{\times}23{\times}3(mm)$ with the impedance of $52-j158{\Omega}$. The maximum distance of identification for the proposed tag is measured as 5.5 meters.

• Journal of the Semiconductor & Display Technology
• /
• v.6 no.2 s.19
• /
• pp.59-63
• /
• 2007

Radio Frequency Identification (RFID) is a common term for technologies using micro chips that are able to communicate over short-range radio and that can be used for identifying physical objects. RFID technology already has several application areas and more are being envisioned all the time. While it has the potential of becoming a really ubiquitous part of the information society over time, there are many security and privacy concerns related to RFID that need to be solved. This paper proposes a method which could protect private information and ensure RFID's identification effectively storing face feature information on RFID tag. This method improved linear discriminant analysis has reduced the dimension of feature information which has large size of data. Therefore, face feature information can be stored in small memory field of RFID tag. The proposed algorithm in comparison with other previous methods shows better stability and elevated detection rate and also can be applied to the entrance control management system, digital identification card and others.

• Journal of Advanced Information Technology and Convergence
• /
• v.9 no.1
• /
• pp.39-46
• /
• 2019

This paper proposes an efficient tag identification scheme for ISO/IEC18000-7 standard by dividing the tags into smaller groups. Tag grouping is based on the reader's transmission power. This can reduce the responding tags in the collection round. If the small number of tags exists, we can anticipate the collision probability will decrease. And it makes the identification speed high. A collection round initiated by the reader's collection command. It also proceeds with increasing the power of the reader until all tags are identified. The results showed that 25% of the performance improved.

• Journal of the Institute of Convergence Signal Processing
• /
• v.5 no.1
• /
• pp.6-12
• /
• 2004

Identification rate and time are very important in the identification of RFID tag, and the tag requires simple structure to use economically large quantity of tags. These factors make the MAC protocols of wired or wireless network environment result in different requirements. In the paper, we propose a method to apply spread spectrum scheme using orthogonal channel via Walsh function as the anti-collision communication system for the purpose of non-collision identification of multiple tags, and consider its property. The proposed system use two step identification. in the first step, collision is resolved via constructing to respond after specific delay time based on unique n, and conventional polling scheme follows in the second step.