• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.30 no.3
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• pp.209-214
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• 2019

This paper presents the design of a 920 MHz ultra-high frequency(UHF) band radio frequency identification(RFID) conductive fabric tag antenna. The resistance values of four different conductive fabrics are measured, and the conductivities of the fabrics are calculated. The fabric with the best conductivity is selected, and the best conductivity of the fabric is used to simulate the fabric tag antenna design. The fabric UHF RFID tag antenna with a T-Matching structure and name-tag size of $80{\times}40mm$ is simulated and designed. The simulated and measured results are compared, and a laundry test is performed. The reading range of the fabric tag antenna is about 2 m. This fabric tag can be easily applied to an entrance control system as it can be attached to other fabrics and cloths.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.18 no.11
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• pp.1211-1216
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• 2007

Yagi-Uda UHF RFID(Radio Frequency Identification) tag antennas with long reading range have been designed. According to ISO-18000, EIRP(Effective Isotropic Radiation Power) of reader and reader antenna is limited as 36 dBm. Therefore, the gain of a tag antenna should be high enough to extend the reading range. Yagi-Uda antenna has been applied to a UHF RFID tag antenna, and high gain and long reading range have been achieved. Three different of Yagi-Uda UHF antennas have been optimized to achieve the small size with low back-lobe patterns. The sizes, reading ranges and return loss of Yagi-Uda tag antennas are compared and measured.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2015.10a
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• pp.648-650
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• 2015

In this research, we investigate an influence of a reader antenna location in Passive UHF RFID system based Object localization. When the localization system uses stationary RFID reader system, the performances of the system are significantly varied depending on the deployed antenna conditions due to its external environment such as reflection by the ground and obstacles. In this research we deeply study the RF conditions and differentiation with various antenna location. According to the empirical results, the localization system shows the best performance, where the reader antenna locates 1.5m from the target area of interest.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.19 no.1
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• pp.1-6
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• 2008

A wearable T-matching dipole UHF RFID tag antenna has been designed using conductive electro-thread. The conductivity of the electro-thread has been measured depending on the number of twisted thread. The measured conductivity has been used for simulation to have accurate simulation results. The flexible electro-thread or fabric has been used for fabricating the antenna instead of using copper tape since the electro-thread is more flexible and wearable than copper tape. The return loss and reading range of the fabricated electro-thread UHF RFID tag antennas have been tested. The reading range is approximately 2.4 m.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.37 no.1C
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• pp.34-37
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• 2012

The paper introduces the an necklace type UHF RFID tag for a live tree having high dielectric constant. When a general UHF RFID tag is used for the metal and the material with high dielectric constant, the electrical characteristics and impedance of antenna have been changed, and the tag is not recognized by an UHF RFID reader. The necklace type UHF RFID tag has been designed with consideration of the high dielectric constant of the tree material. The name tag for a live tree has been designed with the developed tag antenna. The performance of tag has been measured and the reading range is about 4~5m. The developed UHF RFID tag antenna can be applied to any high dielectric material for various industrial applications.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.16 no.2 s.93
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• pp.204-210
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• 2005

In this paper, we are proposed the antennas for RFID tag operated at UHF band which are inserted ground plane easy to mount the RFTD chips at the antenna surfaces. In order to implemented antenna for RFID tag which the size is same as conventional name card, the structure of the antenna is meander type, matching method for improvement characteristics of the antenna use T matching method, ground plane is inserted at the antenna substrate fer mounting RFID chips. The substrate size of implementation is $100\times60\;mm^2$ and the FR4 substrate is used. Results of the experiment, the center frequency of the implemented antenna is 427 MHz, -10 dB return loss bandwidth is 8 MHz, maximum return loss is 21 dB, the radiation pattern is omnidirectional. From these results, we are conformed application for UHF RFID tag antenna.

• ETRI Journal
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• v.34 no.6
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• pp.974-977
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• 2012

In this letter, a small-sized ultra-high frequency (UHF) RFID tag antenna for a medical sample tube is proposed. The RFID tag antenna is designed and fabricated based on the circular loop antenna used in the UHF band (Korea standard, 917 MHz to 923.5 MHz). The tag antenna size is reduced using a circular meander stub. The antenna has a physical size of 8 mm, which is about ${\lambda}$/40 in electrical length. The proposed tag antenna is molded into a medical sample and multitag identification is performed.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.19 no.8
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• pp.1759-1764
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• 2015

In this paper, we considered a design method of a circular polarization (CP) antenna for UHF (ultra high frequency) RFID (Radio Frequency IDentification) readers. The antenna is a dual-fed circular microstrip patch which produces right-handed CP. Quadrature hybrid coupler is used for dual feeding. The outputs of the coupler and circular patch are connected through copper wires, and the inductive reactance produced by the connecting wires is compensated by a ring-shaped slot inserted inside the circular patch. The effects of the geometrical parameters of the proposed antenna on the antenna performance are examined, and the parameters are adjusted to be suitable for the operation in North American UHF RFID band (902-928 MHz), which includes domestic UHF RFID band. The antenna is fabricated, and the experiment results reveal a frequency band of 854-993 MHz for a voltage standing wave ratio < 2. The fabricated antenna is connected to a commercial RFID reader, and it showed a good performance of tag identification.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.37 no.2C
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• pp.168-172
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• 2012

An UHF RFID tag is designed and fabricated using the national code in a bar-code with conductive ink. The bar-code sample was taken from a general bar-code from a general box. The conductivity of the conductive ink was measured, and the measured conductivity was used for the simulation tool to design the printed bar-code shape tag antenna. The tag antenna was fabricated using T-matching to reduce the size of the tag, and the bar-code tag antenna is recognized by both a general bar-code reader and an UHF RFID reader. The input reflection coefficient characteristic, the reading range pattern and the reading rate of the tag antenna are measured.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.42 no.1
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• pp.157-161
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• 2017

This paper introduce UHF miniaturized RFID tag antenna which is embedded on the seal-bolt or plastic bolt for automobile plate. To detect the illegal and un-registered car, the illegal automobile detection system has been developed using the seal-bolt UHF RIF tag antenna. The diameter of seal-bolt UHF tag is about 24mm, almost the same size as 100 Won coin. The simulated and measured reflection coefficient are compared, and the reading range patten is also measured. If seal-bolt tag is embedded on car plate, police can get information of automobile and detect illegal vehicles easily with the illegal automobile detection system.