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Article: QFHA antennas for satellite radio and mobile phone applications. (Technical Feature).(Satellite radio and mobile satellite phone systems require quadrifilar helical antennas)
- Article from:
- Microwave Journal
- Article date:
- July 1, 2002
- Author:
CopyrightCOPYRIGHT 2002 Horizon House Publications, Inc. This material is published under license from the publisher through the Gale Group, Farmington Hills, Michigan. All inquiries regarding rights should be directed to the Gale Group. (Hide copyright information)
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Quadrifilar helical antennas (QFHA) are one of the best candidates to provide a high gain, shaped beam with excellent circular polarization axial ratio for satellite radio and mobile satellite phone systems. One of the most compelling reasons to use these antennas for digital radio and mobile satellite systems is their ability to shape the beam so as to provide more gain in the regions where the satellite is between the horizon and the zenith. Depending on the satellite constellation orbital design, a dip in the antenna gain pattern could be tolerated when the satellite is overhead, because the slant range is minimized. Although there are other approaches to the ...