An Ultra-wideband Circularly Polarized Slot Antenna

In this paper, a circularly polarized slot antenna with ultra-wideband circular polarization (CP) bandwidth is proposed. The proposed antenna fed by L-shaped microstrip consists of a modified ground structure and triangular radiator. Z-shaped slot is employed on the ground structure, which is optimized to get the performance of wide axial ratio (AR) bandwidth for the proposed antenna. The L-shaped microstrip is combined with a triangular patch, which is designed to improve impedance matching and broaden CP operation bandwidth. By simulated and optimized the proposed antenna in the HFSS, the antenna achieves an impedance bandwidth of 73.6% (3.0-6.5 GHz) and an AR bandwidth of 60.9% (3.2-6.0 GHz) respectively. Moreover, more than 3.12 dBi gain and stable radiation patterns are obtained during the operating band for the proposed antenna.