• Journal of the Korea Society of Computer and Information
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• v.13 no.6
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• pp.211-216
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• 2008

Gap fillar antennas are needed for serving the high quality of DMB through the cellular phone by eliminating the shadow regions among buildings or underground. We implement Quadrifilar Helical Antenna using phase difference with PCB feeding lines without coaxial cables and four impedance matching circuits. It is shown that the antenna characteristics is affected by the size and diameter through the simulation process using MicroWave Studio and it is applied for implementing QHA. Experiment results confirm that the performance can be gained as same as the simulation data by using the phase difference with PCB feeding lines without additional impedance matching circuits.

• The Journal of the Korea institute of electronic communication sciences
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• v.4 no.1
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• pp.46-52
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• 2009

This paper design QHA(quadrifilar helical antenna) to receive efficiently Satellite-Digital Multimedia Broadcasting video signal. It is designed as quadrifilar structure with phase variation $0^{\circ}C$, $90^{\circ}C$, $180^{\circ}C$, $270^{\circ}C$ to obtain circular polarization. Upper gap, turn number and height of QHA are varied to obtain optimization dimensions. Optimization dimensions are gap=2.2mm, turn number=0.9, height=42mm and input reflection coefficient is approximately -5.8dB. Designed QHA can be applied to Satellite-DMB terminal.

• Proceedings of the KAIS Fall Conference
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• 2006.05a
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• pp.291-293
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• 2006

본 논문에서는 휴대용 무선통신기기에 장착해서 사용가능한 소형 위성 DMB 안테나를 설계하였다. 안테나 디자인은 QHA(Quadrifilar Helical Antenna)이며 소형화를 위해 안테나 패턴을 유전체위에 감고 각 패턴의 가운데가 분리된 형상을 하고 있다. 시뮬레이션 결과에 따라 안테나가 실제 제작 되고 측정되었다.