Design and Simulation of a Novel Broadband Circularly Polarized Microstrip Slot Antenna

In this paper, a novel broadband printed circularly polarized microstrip slot antenna fed by a co planar wave guide (CPW) is designed, analyzed and simulated. The structure of the proposed antenna is made of a modified stair-shaped patch in conjunction with a square ground plane with a stair-shaped slot inside it. By using a modified stair-shaped patch and square ground plane, additional resonances are excited and, hence, much wider impedance bandwidth can be produced, especially at the higher band. Moreover, by using this structure, especially by adding two rectangular strip to the ground plane, very broadband axial-ratio bandwidth is obtained. the proposed antenna has dimensions of 45×45×0.8 mm3, which is compatible with the requirements imposed by portable wireless systems. Simulation results exhibits a 81.7% (2.78-6.62 GHz) -10 dB impedance bandwidth and a 57.6% (3.5-6.33 GHz) 3 dB axial-ratio bandwidth. the antenna performance confirms its viability for commercial portable wireless systems.