• Journal of electromagnetic engineering and science
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• v.7 no.1
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• pp.47-52
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• 2007

We investigated the effects of substrate, metal-line, and surface material on the performance of radio frequency identification(RFID) tag antenna using a tag antenna with a meander line radiator and T-matching network. The results showed that readability of the tag antenna with a thin high-loss substrate could be increased so that it was similar to that of a low-loss substrate if the substrate was very thin. The readability of the tag antenna decreased significantly when the metal line was thinner than the skin depth. The readability of the tag also decreased drastically when the tag was attached to high-permittivity high-loss target objects.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.19 no.9
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• pp.978-984
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• 2008

In this paper, we propose a RFID metal tag antenna with a minimum by size of a metal surface to attach. This proposed tag antenna is a patch antenna which is able to stick on metal surface and designed for very slim structure ($119{\times}30{\times}1.6$ mm) antenna that is matched to a chip impedance. This has a loop coupling feeding and consists of a inner radiator and a outer radiator. The outer radiator activates the current to concentrate on the inner radiator regardless of metal size to attach. Also the tag antenna is designed by CST microwave tool and the performance is measured in the anechoic chamber. The optimum antenna has 3.77 % of the matching bandwidth($S_{11}<-10$ dB). The readable range of the tag antenna is about 2.9 m on metal(max. size $700{\times}700$ mm) and 5.5 m in free space according to the measurement results.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.2 no.2
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• pp.57-62
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• 2009

In this paper, we proposed the metal tag antenna of PIFA structure with an isotropic radiation pattern when tag attached the metal material. The antenna consist of antenna body, horizontal patch and ground, and inserted a substrate with high dielectric constant between the antenna body and ground in order to miniaturize the antenna size. The antenna body with symmetric structure is designed to produce an oppositely directed currents. The simulation shows the impedance bandwidth has 20 MHz (900 ~ 920 MHz) and the maximum radiation gain satisfy the -10 dBi and -15 dBi when the tag is in air and attach the metal material. Also, the proposed antenna operates with an isotropic radiation pattern due to satisfy the gain deviation lower than 6 dB, respectively.

• Proceedings of the Korea Electromagnetic Engineering Society Conference
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• 2005.11a
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• pp.273-278
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• 2005

The characteristics of the tag antenna are influenced much with the change of the electrical properties of its substrate material, conducting metal-line and the surrounding environments. In this paper, we study the characteristics of tag antenna according to the electrical variations of those substrate materials, metal-line and the surrounding environmental conditions.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.28 no.9
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• pp.679-684
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• 2017

This paper presents an UHF(Ultra High Frequency) band small cavity structured RFID(Radio Frequency Identification) tag antenna with a long reading range, designed to apply on metal cart or pallet for auto-parts logistics. The size of tag antennas is $140{\times}60{\times}10mm^3$, attached on a exporting metal cart, and it can give the information of inventory and logistics of carts. By collecting the exported carts and increasing the recovery rate of missing carts or pallets, the paid import tax can be refunded when the carts are returned back to the manufacture. The tag antenna was equipped with a cover to prevent damage, and the dielectric constant of the cover is considered for the simulation. The reading range of the tag antenna is 12 m using LP(Linear Polarization), 10 m with CP(Circular Polarization) reader antennas. This 920 MHz UHF RFID cavity tag ensures the long reading distance of the antenna regardless of the material of the object where it is attached.

• ETRI Journal
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• v.30 no.4
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• pp.600-602
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• 2008

A very small patch-type RFID tag antenna (UHF band) using ceramic material mountable on metallic surfaces is presented. The size of the proposed tag is 25 mm${\times}$25 mm${\times}$3 mm. The impedance of the antenna can be easily matched to the tag chip impedance by adjusting the size of the shorting plate of the patch and the size of the feeding loop. The measured maximum reading distance of the tag at 910 MHz was 5 m when it was mounted on a 400 mm${\times}$400 mm metallic surface. The proposed design is verified by simulation and measurements which show good agreement.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.19 no.11
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• pp.1265-1271
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• 2008

In this paper, we propose a new antenna design method for RFID tass on metallic surfaces using a low-cost, high-loss substrate such as FR4. The proposed design method highly reduces the substrate loss due to its dielectric loss, and so improves the radiation efficiency of the tag antenna more than double compared with a conventional PIFA(planar inverted-F antenna). The equivalent circuit model of the antenna according to the proposed method was established and its characteristics were analyzed systematically in this paper. The excellency of the proposed design method was verified by the fabrication and measurement of a prototype antenna.

• Journal of electromagnetic engineering and science
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• v.12 no.2
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• pp.176-184
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• 2012

In this paper, the effects of a metal plane on the performance of a meandered slot RFID antenna are evaluated in a real environment, and 3 metal plane cases are considered (the most likely scenarios in which metal conductive materials are placed near the tag antenna). The metal plane effects can be categorized as matching degradation and antenna gain variation. First, matching degradation due to the antenna's induced mutual impedance is experimentally investigated. In addition, the gain variation is investigated to figure out the change in the radiation characteristics. With the derived antenna parameters, the read range is calculated with the Friis transmission equation and measured to analyze the effects of a metal plane on RFID system performance. The calculated and measured read range varies from 9.3 m to 19.1 m as the distance between the RFID antenna and the metal plane changes.

• 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.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.6 no.9
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• pp.2253-2265
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• 2012

A novel folded dipole type microstrip patch antenna designed for ultrahigh frequency (UHF) band radio frequency identification (RFID) tag is presented in this paper, which can be used on the metallic objects. The presented antenna is fabricated on a very thin Rogers 5880 substrate with a thickness of 0.508 mm. The structure consists of two folded dipole and two symmetrical shorting pins placed at both sides of feed point. An adjustable frequency response can be easy obtained via modify the location and radius of the shorting pins. The antenna has been analyzed by full wave simulations soft. The simulated bandwidth is about 67.2 MHz, which covers the Europe and North America UHF RFID frequency range. A manufactured prototype has been fabricated and measured to demonstrate the antenna performances. The simulation results agree with the measurement data well. The measured maximum reading range of the prototype can be reached 4.1 m in free space, and 3.2 m on a metal plate whose size is $150{\times}150{\times}8mm^3$.