A design of wideband circularly polarized antenna with high gain.

ABSTRACT A wideband circularly polarized (CP) antenna with high gain is proposed. The circular polarization performance is obtained by two pairs of orthogonal bowtie dipoles with a coaxial balun feed and a broadband 90° hybrid feed network. Particularly, a design of rectangular ring with eight shorted posts is added around the bowtie dipoles, which can obtain a high gain. To further improve the gain of the novel antenna, a circular ring is placed around the rectangular ring on the same plane. With such an arrangement, the proposed antenna delivers a higher gain than that of the conventional dual-fed type CP antenna. The measured results show that the proposed antenna can achieve a measured impedance bandwidth for VSWR ≤ 1.5 of 61.5% and a 3-dB axial ratio bandwidth of 66.7%. The antenna has a stable peak CP gain better than 10.3 dBi ranging from 1.1 to 1.6 GHz. © 2014 Wiley Periodicals, Inc. Microwave Opt Technol Lett 56:1274-1277, 2014 [ABSTRACT FROM AUTHOR]