A Circular Polarization Microstrip Stacked Structure Broadband Antenna

This paper describes a single-feed S-Ring type stacked microstrip structure antenna for broadband applications. The antenna is designed for RHCP/LHCP at a center frequency of 2.1GHz. The design of the antenna is aimed at obtaining both wider bandwidth on the impedance and better circular polarization AR (Axial-Ratio) for GPS (global positioning system) applications. The feeding technique and structures of the present antenna has been analyzed. The results of simulations and measurements results show that the antenna has an impedance bandwidth (VSWR.52) of 30% and a 3-dB AR bandwidth more than 23%.