Compact wideband circularly polarised resonant cavity antenna using a single dielectric superstrate

A wideband resonant cavity antenna (RCA) with circular polarisation (CP) and high‐gain characteristics is presented. A crossed bowtie dipole is used as a primary wideband CP radiator for the RCA. A half‐wavelength planar partially reflecting surface is utilised to achieve high‐gain broadside radiation and wide axial ratio (AR) as well as gain bandwidths. The final design yields measured −10 dB impedance and 3 dB AR bandwidths ranging from 5.6 to 8.4 GHz and from 6.3 to 8.15 GHz, respectively. Experimental results also showed an average gain of 14.5 dBic over the CP operating bandwidth and a 3 dB gain bandwidth of 42.7% (5.7–8.8 GHz).