A circularly polarized dielectric resonator antenna excited by an asymmetrical U-slot

A circularly polarized (CP) low-profile dielectric resonator antenna excited by an asymmetrical U-slot is investigated theoretically and experimentally. The nonuniform orthogonal grids finite-difference-time-domain (FDTD) method with source independent resistive voltage source (RVS) model is adopted in the simulation. The return loss, input impedance, axial ratio, radiation pattern, and gain of the antenna are studied. The calculations compare fairly well with measurements.