A cavity-backed wideband circularly polarized crossed bowtie dipole antenna with sequentially rotated parasitic elements

Abstract

A cavity-backed crossed bowtie dipole antenna for wideband circularly polarization (CP) is proposed in this letter. By introducing four inverted L-shaped parasitic elements with sequentially rotated angles, two extra CP modes are excited, thus greatly broadening the 3-dB Axial-ratio (AR) bandwidth (BW) of the antenna. The proposed antenna is simulated, fabricated and measured. Results show that the antenna generates a 10-dB impedance bandwidth (IBW) of 91.4% (1.2–3.22 GHz) and a 3-dB AR bandwidth of 74.1% (1.37–2.95 GHz). In addition, the antenna achieves a unidirectional radiation pattern with a stable gain of 6.52–9.27 dBi over the whole CP operating band.