A Low-Profile Dual-Band Dual-Sense Circularly Polarized DRA

In this paper, a low-profile dual band dual polarized DRA is proposed. In the lower band, the dielectric resonator (DR) is excited by the cross slots etched on the ground plane fed by a microstrip line under the substrate, and the left-hand circular polarization (LHCP) is controlled by the cross slots, and the profile is reduced by the air vias etched in the DR. In the upper band, the four DRs arranged counterclockwise around the center are excited by the rectangle slots in the ground plane, which is fed by a one-quarter Wilkinson power divider with a 90° phase difference for each port and the right-hand circular polarization (RHCP) is attained. The simulated results achieve an available bandwidth of 15.4% (2.41-2.81GHz) in the lower band and 31.5% (2.97-4.08GHz) in the upper band with a profile of
$0.11 \lambda$
.