Wideband Circularly Polarized Filtering Hybrid Antenna

In this paper, a wideband circularly polarized (CP) filtering hybrid antenna is presented. The liquid dielectric resonator (DR) excited by microstrip-coupled cross-slot to generate CP radiation. Four inverted L-shaped strips are loaded on the ground plane introduce an additional resonant point, then two adjacent axial ratio (AR) minima combined improve bandwidth of single-feed antenna. By etching U-shaped slot and loading C-shaped microstrip stub line, tunable radiation nulls near edges working band can be obtained without any extra circuits. To verify design, designed, fabricated, tested. Measured results show that provides wider 3-dB AR impedance 38.8% from 1.36 2.02 GHz 39.4% 1.37 2.04 GHz, respectively. realized gain proposed stable at about 7.8 dBi within whole band. A reasonable agreement between measured simulated observed.