Low-Cost Broadband Circularly Polarized Printed Antennas and Array

Steven Gao, Yi Qin, Alistair Sambell

Research output: Contribution to journalArticlepeer-review

61 Citations (Scopus)


This paper presents the design, simulation, and measurements of two low-cost broadband circularly polarized (CP) printed antennas: an element and an array at 2 GHz. To realize the broadband circularly polarized antenna element, a circular microstrip patch is electromagnetically coupled by crossed slots cut in the ground plane, which is fed by an L-shaped microstrip feed. Two orthogonal modes in the patch are excited by using the crossed slots, and a single L-shaped feed provides a 900 phase shift between two orthogonal slots. The antenna element achieves a 9.6% bandwidth for an axial ratio (AR) below 3 dB and a voltage standing wave ratio (VSWR) below 1.5. To further improve the performance, a sequentially rotated feed network is designed for a 2 x 2 array. The axial ratio value of the array is below 3 dB within a 27.2% bandwidth, from 1.75 GHz to 2.3 GHz. The return loss is above 10 dB within a 41 % bandwidth, from 1.62 GHz to 2.45 GHz. Details of the proposed antenna element and the array design are described, and both the simulation and the experimental results are presented and discussed.

Original languageEnglish
Article number4385597
Pages (from-to)57-64
Number of pages8
JournalIEEE Antennas and Propagation Magazine
Issue number4
Publication statusPublished - 1 Aug 2007
Externally publishedYes

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