Circularly polarized square slot antenna using crooked T-shape technique

This paper presents the investigation results on a novel circularly polarized square slot antenna (CPSSA) designed to operate at a frequency of 5.5 GHz. In order to realize the proposed antenna, miniature circular polarized square slot antenna is used with L-shape and crooked T-shape grounded strips located at the slots opposite corners to reduce cross-polarization. The antenna is fed by coplanar waveguide. The 3 dB axial-ratio of the CPSSA extends to approximately 2 GHz. The CPSSA was designed to operate over the frequency range between 3 and 11.1 GHz corresponding to an impedance bandwidth of 115% for VSWR<2. Acceptable agreement between the simulation and measured results validates the proposed design.