LAUSR

This paper presents a compact wideband circularly‐polarized square slot antenna (CPSSA). The antenna is a coplanar waveguide feed structure with three T‐stubs toward the slot center and one semi‐circle tuning stub was etched to the feed line and modified inverted L‐shaped strips around the corners of the ground. Moreover, two spiral slots were loaded in the ground plane for exciting currents in a different direction. A prototype of the designed antenna is fabricated and measured to confirm the simulation results. A reasonably good agreement between the measured and simulated results in terms of the reflection coefficient <−10 dB and axial ratio are achieved. The 3‐dB axial ratio bandwidth achieved by the combination is from 4.35 to 8.15 GHz (60%, measured). The designed CPSSA has a compact size of 0.57λₒ × 0.57λₒ × 0.0116λₒ at the center frequency and fabricated on the FR4 substrate.