A three-dimensional circularly polarized antenna with a low profile and a wide 3-dB beamwidth

Abstract

An improved three-dimensional circularly polarized quadrifilar helix antenna (QHA) with low profile and wide 3-dB beamwidth is proposed and its performance is investigated both numerically and experimentally. The proposed modified QHA is comprised of a short-circuited quadrifilar helical antenna printed on a thin FR4 substrate, with its four ports terminated by 50 Ω resistances. In addition, four monopoles with 90° phase progression are positioned around the quadrifilar helical antenna, and four Archimedean spirals are used to top-load the monopoles. Simulated and measured results show that the proposed antenna achieves a bandwidth of 23.8%, has a 3-dB beamwidth greater than 170°, and its axial ratio is less than three in the entire upper hemisphere over a wide frequency band.

Keywords:

• quadrifilar helix antenna
• circularly polarization antenna
• wide beamwidth
• low-angle coverage

Acknowledgment

The authors would like to thank Dr Tianyu Dong of the State Key Laboratory of Electrical Insulation and Power Equipment for his valuable comments and constructive suggestions. The author would also like to thank Mr Zhou in Yantai Xinrui Technology Co., Ltd. for his kind suggestions to modify this antenna, and his help in the fabrication and the measurement.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported in part by a grant from Pre-Research Fund of the 12th Five-Year Plan [grant number 4010403020102]; Fundamental Research Funds for the Central Universities [grant number HEUCFD1433].