• Journal of the Institute of Electronics and Information Engineers
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• v.52 no.2
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• pp.75-79
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• 2015

In this paper, a dual band antenna with the operating frequency in HF and UHF band was proposed. The antenna structure consists of three spiral turns coil in the bottom side to generate the HF frequency of 13.56 MHz. In the top of the antenna, an inverted-spiral dipole structure is used to create the UHF frequency of 922 MHz. The dual band antenna was optimized to reduce size with $80mm{\times}40mm{\times}0.8mm$ dimension. The antenna presents the omnidirectional characteristic with high gain. To validate the theoretical design, the antenna was simulated using FR-4 substrate and verified the simulation results.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.13 no.1
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• pp.193-198
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• 2009

In this paper, we report the design of UHF RFID ceramic antenna using HFSS, one of the widely used RFID design tools. Of the developed antenna system, we analyze its Return Loss using HFSS and its characteristics using Smith Chart methodology. We built the ceramic antenna system based on the HFSS design, and analyzed its performance by measuring the impedence matching and gains using Network Analyzer. We attach the developed prototype to UHF RFID portable terminal, and performed distance measuring for five widely used types of RFID tags to verify the performance of our proposed antenna system.

• 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.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2017.05a
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• pp.63-64
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• 2017

In this paper, we studied a design method for a coplanar waveguide-fed compact quasi-Yagi antenna for a dual band of the UHF RFID (915 MHz) and GPS (1.575 GHz). The proposed antenna is composed of three elements of a dipole, a reflector, and a director. To reduce its size, the ends of both the dipole and reflector are bent, the director is placed near to the dipole, and a balun is incorporated in the antenna. From some simulations, the proposed antenna using an FR4 substrate with 0.8 mm thickness was designed for the operations in the UHF RFID and GPS systems, and the antenna characteristics such as reflection coefficient, gain, and radiation patterns were examined.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.38C no.11
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• pp.982-989
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• 2013

Omni-directional antennas of UHF-Band are located on the top and bottom side of the Smart UAV in order to connect a link always. Therefore one of each antennas should be connected to a ground antenna. Because the communication link of the omni-directional antennas is influenced by the objectives around aircraft, the clearance of LOS(Line of Sight) should be achieved in order to avoid a loss of link. In this paper, the analysis results on the influence of the complex objectives placed around the antenna on the communication link are presented according to the change of attitude angles. The best positions of antennas are selected based on the electromagnetic analysis using XGTD tool which supports the modeling of antenna pattern. The flight tests of the Smart UAV were successfully performed with the selected antenna position.

• 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 The Korea Institute of Intelligent Transport Systems
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• v.5 no.1 s.9
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• pp.65-70
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• 2006

A UHF band RFID passive tag antenna, which can be attached on metallic objects, is proposed. The proposed tag antenna is more insensitive to the size of the metallic object than conventional PIFAs or IFAs. It is constructed on a multi-layer and its size is reduced by using a 'L' slit. Performances of the antenna is analyzed by Ansoft's HFSS and measured using a back-scattering method. The simulated and measured data are obtained with varying the size of metallic object.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.25 no.6
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• pp.619-627
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• 2014

In this paper, we designed a blade antenna for VHF-UHF band(500 MHz~3 GHz) to be used as aircraft antennas. Unlike previously reported researches that use high-dielectric materials and insert rectangular extended grounds, the antenna structure was designed by optimizing the curvature of both a radiator and an extended ground whose shape is varied by changing the exponent of an n-th polynomial. Based on the optimized structure, we measured impedance matching and gain performances to evaluate the antenna in the VHF-UHF band(500 MHz~3 GHz). As a result, we confirmed that the antenna shows matching characteristics of less than -6 dB and has average gains of greater than -5 dBi in the entire VHF-UHF band.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.27 no.11
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• pp.972-977
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• 2016

This paper introduces development process and results of HF & UHF band(13.56 MHz, 920 MHz) tag antennas using a single-side printing method on a PE film. The size of tag antenna is designed in the area of $80mm{\times}50mm$, little bit smaller than a credit card. The UHF tag antenna, $76mm{\times}44mm$, is located at the outside of the card size tag antenna, and the HF tag antenna, $40 mm{\times}42 mm$, is located at the center of the UHF tag antenna. The UHF and HF tag antennas are designed with consideration of coupling effects. The single-side printing method with a jumper structure without using a via is used to make a loop antenna of HF tag antenna. The reading range of UHF tag antenna is about 6m, and the reading of HF tag antenna is about 5 cm. The designed tag antennas have long enough reading ranges for both bands. The tag is applicable to logistics and authentification.

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