A Reconfigurable Broadband Circularly Polarized Dielectric Resonator Antenna

A broadband circularly polarized (CP) reconfigurable dielectric resonator antenna (DRA) featured with low profile and wideband is proposed in millimeter wave band. In this design, a two-layer dielectric resonator with improved performance in bandwidth and gain is used as the basic resonator. A cross-slot is employed to feed the DRA to generate CP radiation. Four PIN diodes are placed across the cross-slot to reconfigure the length of cross-slot and switch between left-hand circular polarization (LHCP) and right-hand circular polarization (RHCP). Simulated results show that the proposed reconfigurable DRA has a -10 dB impedance bandwidth and a 3 dB axial ratio bandwidth of about 40% and 30%, respectively. It also has a stable radiation pattern with an average gain of 8.5 dBic within the bandwidth in each polarization state.