Wideband Circularly Polarized Waveguide-Fed Antipodal Exponential Tapered Slot Antenna

A novel waveguide-fed antipodal exponential tapered slot antenna (AETSA) is investigated to achieve wideband circular polarization. The proposed AETSA is fed by double-ridge waveguide and loaded with antipodal exponential tapered slots. The wideband axial ratio (AR) performance is discussed in detail. It is noted that this AETSA has a right-hand circularly polarized AR lower than 3 dB in 94.5% bandwidth, from 12.4 to 34.6 GHz, illustrating AETSAs potential in a wideband application. The measured VSWR is lower than 2.1 in the operating band. Gain varies from 8.3 to 18.3 dBi. This AETSA is suitable for millimeter-wave and terahertz wideband circular polarization applications.