• Journal of the Korean Institute of Telematics and Electronics
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• v.15 no.2
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• pp.15-18
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• 1978

The impedance step up ratio and variations of input admittances of the folded dipole antenna are calculated by the moment method. The results are compared with those calculated by Guertler's formula. The input admittance of the folded dipole antenna has the maximum value at the frequency somewhat lower than the resonance frequency and its susceptance which has periodic properly is null lot several different frequencies if radius ratio of two elements is not very large. Frequency characteristic of folded dipole antenna is improved when its radius ratio is increased.

• Journal of Electrical Engineering and Technology
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• v.11 no.6
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• pp.1777-1782
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• 2016

A compact and broadband balun is designed using a conventional right-handed transmission line (RHTL) and a left-handed transmission line (LHTL) with lumped elements only. The proposed balun maintains a phase difference of $180^{\circ}{\pm}12^{\circ}$ at the output ports for the frequency range of 1.27 GHz-2.69 GHz. Nevertheless, the circuit size is merely $9.5mm{\times}12.7mm$. To verify the performance of the proposed balun, we attached it to a dipole-type antenna and observed that the return loss is greater than 10 dB for the frequency range between 1.86 GHz and GHz. The radiation pattern and peak gain are similar to those of the dipole antenna with a conventional balun.

• Journal of electromagnetic engineering and science
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• v.10 no.3
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• pp.171-174
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• 2010

In the paper, a printed dual-dipole array antenna is presented. A 4-way planar SIW power divider is adopted for feeding the array antenna. The dual-dipole is adopted as radiation elements which greatly improves the impedance band. The measured bandwidth larger than 31 % for VSWR$\leq$1.5 operating near 14 GHz is achieved and in agreement with the simulated results. The radiation E-plane and H-plane radiation pattern is presented in the paper. The radiation gain is also presented in the paper.

• Proceedings of the KIEE Conference
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• 1989.07a
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• pp.647-650
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• 1989

The driving-point impedance of the center-fed planar dipole antenna is obtained using the method of moments (MOM). For the thin dipole antenna, our numerical result is compared with that of the inverse method by D. R. Rhodes as well as the known solutions of equivalent wire antenna. For the frequencies of L-band and S-band, the driving-point impedances of the thick planar dipole antennas are measured by experiment and compared with the numerical results.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2018.05a
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• pp.57-58
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• 2018

In this paper, we studied a design method for a quasi-Yagi antenna operating over a broad bandwidth covering the UHF RFID(902-928 MHz) and GNSS(1,164-1.605 MHz). The proposed antenna is composed of three elements(dipole, reflector, and director) and fed by a coplanar waveguide. To reduce its size, a balun is integrated inside the antenna, and the ends of both the dipole and reflector are bent. Broadband impedance matching was obtained by placing the director near to the dipole and loading a chip capacitor inside the antenna. The antenna, designed through simulations, was fabricated on an FR4 substrate with 0.8 mm thickness. The experiment results for the antenna characteristics agree very well with the simulation.

• Journal of the Korea Institute of Military Science and Technology
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• v.9 no.1 s.24
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• pp.33-40
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• 2006

A compact broadband active composite dipole antenna for direction finding system at the V/UHF-band is presented. It uses the composite structure which improves the antenna gain and the active circuit for broadband operation. This type of antenna has a high gain more than that of one dipole antenna within limited length(1m). The basic design and performance of both antenna structure and integrated active circuit are presented.

• 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.

• 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.

• 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 $150{\times}150{\times}8mm^3$.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2006.05a
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• pp.628-631
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• 2006

This paper explains about the design, fabrication, and measurement of directional dipole antenna for MMDS. The proposed dipole antenna is an electric wave guide with a director at $\lambda/4$ distance and is also designed to have directivity. The high gain antenna is realized by using a reflector at $45^{\circ}degree$. The fabricated antenna shows the return loss of -35dB at the center frequency 2.06GHz and also has the bandwidth of about 310MHz (>15%) under the condition of VSWR<2. The gain of dipole antennas is 11.5dBi.