Wideband Millimeter-Wave Elliptical Cavity-Backed Antenna for Circularly Polarized Radiation

A wideband millimeter-wave antenna backed by an elliptical cavity for circularly polarized radiation, excited by a dipole inclined to the major axis direction of the cavity, is reported in this letter. Experimental results show that the proposed antenna can achieve a bandwidth of 50-62.8 GHz for both axial ratio ≤ 3 dB and reflection coefficient | S₁₁| ≤ - 10 dB, and an average broadside gain of 7.8 dBi. Studies on four critical parameters are performed for practical design. This design yields good directional radiation patterns and low fabrication cost.