Single-Fed Wide-Beamwidth Circularly Polarized Antenna Using Reflector-Loaded Bent Dielectric Resonator
In the paper, a compact single-fed wide-beamwidth circularly polarized (CP) antenna is proposed. The main radiator of the antenna is a bent dielectric resonator (DR), which is conformal to a rectangle substrate with the same curvature and is excited through a crossed-two-ring slotted ground fed by a T-shaped feeding line. By bending the DR to different curvatures, the half-power bandwidth (HPBW) of the dielectric resonator antenna (DRA) can be adjusted. Besides, to improve the 3-dB axial ratio (AR) beamwidth, as well as further enhance the HPBW, a copper reflector is inserted below the DRA. A prototype operating in BeiDou Navigation Satellite System (BDS) B1 band (1.561 GHz) was designed, and measurement was done to verify the simulations. Measurement results show that from 1.55 GHz to 1.58 GHz, the return loss is more than 10 dB and the AR is less than 3 dB. At 1.561 GHz, the measured 3-dB AR beamwidths are 165° and 210° at xoz and yoz planes, respectively, while the HPBWs are 143° and 154° at the two planes.