Circularly Polarized Dielectric Resonator Antenna with Two Annular Vias

In this paper, a new technique for circular polarization in a slot coupled dielectric resonator antenna is proposed. The circular polarization is generated by inserting the two annular vias into dielectric resonator slightly off the diagonal position. In addition to the circular polarization, the proposed technique increases the total realized gain by 1.62 dB as compared to the via-less case on the account of increased directivity while maintaining the same aspect ratio of the DR. To validate the design, a prototype is fabricated and measured. The measured results show that the proposed circularly polarized dielectric resonator antenna has a -10 dB reflection bandwidth of 7.29% (3.3-3.55 GHz) and a 3 dB axial ratio bandwidth of 5.5% (3.28-3.465 GHz) with a measured RHCP gain of 6-7.1 dBic. The measured curves of the S11, axial ratio, and the RHCP gain results are in good agreement with the simulated results.