• 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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• v.9 no.2
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• pp.1091-1094
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• 2005

This paper presents analysis and design for printed directive antenna using Bluetooth AP system. For the miniaturization of the antennas, dielectric substrate (${\varepsilon}_r$=4.6) and planar line Yagi-Uda antenna structure are used. The proposed Yagj-Uda antennas are simulated using commercial simulator (HFSS). The results of the simulation are presented and compared with characteristics of each array type. Especially, the proposed antennas can be applied to the design of various communication systems for 2.4 GHz band.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2016.10a
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• pp.195-196
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• 2016

In the maritime mobile radiocommunication service, AIS(Automatic Identification System) devices are most widely using for the exchange of ship's navigational information. The AIS time slot usage increases due to increasing number of ships installed with AIS, and thus the reception rate of AIS data decrease. In order to mitigate this problem, international organizations recommend a sectorised receiving technique using directional antenna. This paper analyzed the sectorised receiving effectiveness of AIS data using Yaga antenna.

• The Journal of the Korea institute of electronic communication sciences
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• v.13 no.3
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• pp.533-538
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• 2018

For WLAN dual-band operation, a modified Yagi dipole antenna is presented. The modified dipole antenna consists of a dipole antenna with open sleeves and parasitic elements. The parasitic elements are used for the practical application of the radiation patterns and high-gain operation at the WLAN dual band. The experimental results showed that the achieved impedance bandwidths were 320 MHz (2.4 to 2.72 GHz) and 640 MHz (5.04 to 5.68 GHz), respectively. The measured maximum gain at the two WLAN bands was 7.74 dBi and 6.93 dBi, respectively.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.20 no.1
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• pp.15-21
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• 2016

In this paper, we considered a design method of a compact quasi-Yagi antenna for portable UHF RFID readers. The antenna consists of a dipole driver and a reflector printed on a dielectric substrate, and it is fed by a microstrip line. In order to reduce the antenna size, the dipole and reflector are bent and the balun between the feeding microstrip line and coplanar strip (CPS) line is integrated within the CPS line. 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 UHF RFID band (902-928 MHz). The size of the fabricated antenna is $70mm{\times}75mm$, and the experiment results reveal a frequency band of 892-942 MHz for a voltage standing wave ratio < 2, a gain > 3.5 dBi, and a front-to-back ratio > 6.6 dB over the frequency band for UHF RFID.

• Journal of Advanced Navigation Technology
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• v.22 no.5
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• pp.436-441
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• 2018

In this paper, a design method for a compact double dipole quasi-Yagi antenna with a V-shaped ground plane operating in dual bands including 2.45 GHz and 5 GHz wireless LAN frequency bands is studied. First, a quasi-Yagi antenna operating in the 2.45 GHz band is designed, and a V-shaped ground plane is used instead of a conventional strip ground plane to reduce the length of the antenna. A second dipole is connected to the dipole driver of the quasi-Yagi antenna for 2.45 GHz band and a director is appended for 5 GHz band operation. A prototype of the proposed dual-band antenna operating at 2.45 GHz WLAN band and 4.57-7.11 GHz band is fabricated on an FR4 substrate with a dimension of 40 mm by 55 mm. Fabricated antenna shows frequency bands of 2.33-2.75 GHz and 4.38-7.5 GHz for a voltage standing wave ratio less than 2. Measured gain remains more than 4 dBi in both bands.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.20 no.12
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• pp.2199-2205
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• 2016

In this paper, a design method for a coplanar waveguide (CPW)-fed 2-element quasi-Yagi antenna (QYA) is studied. A balun between CPW and coplanar strip (CPS) which feeds a planar dipole is implemented by connecting the one end of ground strips in a CPW to a signal strip. The antenna size is reduced by bent strip dipole and reflector, and an integrated balun. The proposed antenna was designed for the operation in a UHF radio frequency identification (RFID) band of 902-928 MHz, and the effects of various parameters such as dipole length, reflector length, distance between dipole and reflector, feed position were examined. The antenna with a size of $90mm{\times}80mm$ was fabricated on an FR4 substrate, and the experiment results reveal a frequency band of 885-942 MHz for a voltage standing wave ratio < 2, a gain > 4.3 dBi, and a front-to-back ratio > 7 dB over the frequency band for the UHF RFID.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.21 no.4
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• pp.672-678
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• 2017

In this paper, we studied a design method for a broadband quasi-Yagi antenna (QYA) for terrestrial digital television (DTV) reception. The proposed antenna is composed of a dipole driver, a rectangular patch type director close to the dipole, and a ground reflector printed on an FR4 substrate. A balun between a microstrip line and a coplanar strip (CPS) line is a rectangular patch inserted along the center of the CPS. The end of the balun is connected to the CPS line through a shorting pin. An antenna, as an design example for the proposed antenna, is designed for the operation in the frequency band of 470-806 MHz for terrestrial DTV, and the characteristics of the designed antenna are examined. The antenna has a good performance such as a frequency band of 430-842 MHz for a voltage standing wave ratio < 2, a gain > 3.7 dBi, and a front-to-back ratio > 7.4 dB.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.11
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• pp.4515-4521
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• 2010

A Yagi antenna, which is a typical directional antenna, has been designed and fabricated as a surveillance sensor. The proposed Yagi antenna satisfies the requirements as a surveillance sensor; impedance bandwidth of 7.2-8.2GHz, maximum gain of 7dBi, and 3dB beamwidth of $60^{\circ}$ in the azimuthal plane. The proposed Yagi antenna is designed with 3 directors and one driven element on a dielectric substrate. Also, a microstrip-to-CPS balun is designed and applied to the proposed antenna for balanced feeding of the dirven element. The performance of the proposed antenna has been verified by comparing the simulation and measurement results.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.21 no.5
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• pp.906-912
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• 2017

In this paper, we studied a design method for a broadband 3-element quasi-Yagi antenna (QYA) for indoor digital television (DTV) reception. The proposed QYA employs a novel balun between a microstrip (MS) line and a coplanar strip (CPS) line feeding the driver dipole. The proposed balun is constructed by connecting the end of MS line to CPS line through a shorting pin, and the CPS and ground reflector are connected through a circular ring-type conductor. An antenna, as an design example for the proposed antenna, is designed for the operation in the frequency band of 470-806 MHz for terrestrial DTV. The antenna fabricated on an FR4 substrate with a size of $270mm{\times}150mm$ showed a good performance such as a frequency band of 470-820 MHz for a voltage standing wave ratio < 2, a gain > 4.0 dBi, and a front-to-back ratio > 8.4 dB over the DTV frequency band.