• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.8 no.1
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• pp.45-52
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• 2009

In this paper, a new rectenna is presented for the wireless transmission of microwave power using dipole antenna (Quasi Yagi effect) and rectifier of CPS resonator structure. The dipole antenna with CPW feedline has high peak gain than a general dipole antenna. A ground plane of CPW is used to reflect a dipole as a Yagi antenna. Therefore, the new rectenna receives the RF power better than the one using general dipole. A RF-to-DC conversion efficiency of 61 % using a 1.4 $k{\Omega}$ load resistor is obtained at 5.8 GHz.

• Journal of Advanced Navigation Technology
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• v.27 no.4
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• pp.447-452
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• 2023

In this paper, gain enhancement of a double dipole quasi-Yagi antenna using a meanderline array structure was studied. A 4×1 meanderline array structure consisting of a meanderline conductor- shaped unit cell is located above the second dipole of the double dipole quasi-Yagi antenna. It was designed to have gain over 7 dBi in the frequency range between 1.70 and 2.70 GHz in order to compare the performance with the case using a conventional strip director. As a result of comparison, the average gain of the double dipole quasi-yagi antenna with the proposed meander line array structure was larger compared to the case with the conventional strip director. A double dipole quasi-Yagi antenna using the proposed meanderline array structure was fabricated on an FR4 substrate and its characteristics were compared with the simulation results. Experiment results show that the frequency band for a VSWR less than 2 was 1.55-2.82 GHz, and the frequency band for gain over 7 dBi was measured to be 1.54-2.83 GHz. The frequency bandwidth with gain over 7 dBi increased, and average gain also slightly increased, compared to the conventional case using a strip director.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.20 no.3
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• pp.457-463
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• 2016

In this paper, a method of enhancing the bandwidth of a double-dipole quasi-Yagi antenna (DDQYA) using a modified integrated balun is presented. The modified integrated balun consists of a microstrip (MS) line inserted along the center of a coplanar strip (CPS) line and the end of the MS line is connected to the CPS line through a shorting pin at the feed point. The geometry of the modified integrated balun is adjusted to improve the bandwidth of the DDQYA. In addition, the performance of the proposed balun in a back-to-back configuration is compared with a conventional balun. The proposed antenna with the optimized modified integrated balun is fabricated on an FR4 substrate, and the experiment results show that the antenna has a frequency band of 1.56-3.04 GHz(64.4%) for a VSWR < 2, which shows enhanced bandwidth compared to the DDQYA with the conventional balun.

• 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 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.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.21 no.2
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• pp.252-258
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• 2017

In this paper, the bandwidth and gain enhancement of a double-dipole quasi-Yagi antenna (DDQYA) using a modified balun and two directors is studied. The proposed DDQYA consists of two strip dipoles with different lengths, a ground reflector, which are connected through a coplanar strip line, and two directors. The modified balun is used to increase the bandwidth, whereas two directors are appended to the DDQYA to enhance the gain in the middle and high frequency band. The effects of the length and width of the first director on the antenna performance are analyzed, and final design parameters to obtain a gain over 7 dBi at 1.60-2.90 GHz band are obtained. A prototype of the proposed DDQYA is fabricated on an FR4 substrate, and the experimental results show that the antenna has a frequency band of 1.57-3.00 GHz for a VSWR < 2, and measured gain ranges 7.1-7.8 dBi at 1.60-2.90 GHz band.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2017.10a
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• pp.59-60
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• 2017

In this paper, we studied a design method for obtaining broadband property by loading a chip capacitor on a coplanar waveguide(CPW)-fed compact quasi-Yagi antenna(QYA). The proposed antenna is a three-element QYA with dipole, reflector, and director. To reduce the size, the ends of both dipole and reflector are bent, and balun is incorporated in the antenna. To improve impedance matching, the loading position and capacitance value of chip capacitor were determined. From some simulations, the proposed antenna using an FR4 substrate with a size of 90 mm by 90 mm was designed for the operation in a broadband covering the UHF RFID and GPS systems. The antenna showed a good performance with a broadband of 850-1,626 MHz(62.7%) for a VSWR ${\leq}2$, a gain ${\geq}3dBi$, and a frong-to-back ratio ${\geq}4.6dB$.

• Journal of Advanced Navigation Technology
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• v.26 no.1
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• pp.29-34
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• 2022

In this paper, the design of a triple dipole quasi-yagi antenna operating in the 2.45 GHz and 5 GHz wireless LAN frequency bands and the 3.5 GHz WiMAX frequency band was studied. The proposed quasi-Yagi antenna consists of three dipoles connected in series with a V-shaped ground plane. The longest half-bow-tie-shaped dipole resonates in the 2.45 GHz band, whereas the medium-length dipole resonates at 3.5 GHz. The shortest dipole resonates in the 5 GHz band. By adjusting the length and width of the dipoles and the spacings between the dipoles, a triple-band directional antenna operating in the 2.45 GHz, 3.5 GHz, and 5 GHz bands are designed, and fabricated on an FR4 substrate with a size of 45 mm × 55 mm. It was confirmed that the fabricated antenna operates in the designed triple bands of 2.32-2.57 GHz, 3.26-3.69 GHz, and 4.50-6.56 GHz for a voltage standing wave ratio less than 2. Gain is maintained above 3 dBi in the three bands.

• 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.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.9
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• pp.4165-4170
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• 2012

In this paper, a method for the improvement in the gain and bandwidth of a microstrip-fed broadband planar quasi-Yagi antenna (QYA) is studied. The broadband characteristics of the QYA are achieved from the coplanar strip-fed planar dipole driver and a parasitic director close to the driver. In order to obtain stable gain variation over the required frequency band, a director and a ground reflector are appended to the driver having a nearby parasitic director. The QYA is fed through an integrated balun composed of a microstrip line and a slot line which are terminated in a short circuit. By adjusting the feeding point, a broadband impedance matching is obtained. A QYA with an operating frequency band of 1.75-2.7 GHz and a gain > 4.5 dBi is designed and fabricated on an FR4 substrate with dielectric constant of 4.4 and thickness of 1.6mm. The experimental results show that the fabricated antenna has good performance such as a broad bandwidth of 59.7%(1.55-2.87 GHz), a stable gain between 4.7-6.5 dBi, and a front-to-back ratio > 10 dB. The measured data agree well with the simulation, which validates this study.