GPS wideband microstrip antenna array featuring compact Schiffman phase shifters

A design for microstrip antenna for Global Positioning System (GPS) applications is presented in this paper. The antenna design utilizes a 2×2-element circularly polarized array supported on a multi-layer substrate architecture. A design concept for a compact version of Schiffman phase shifter is also introduced. Implementation of the new phase shifters within the feed design significantly reduces the overall surface area of the microstrip array. The design achieves an exceptionally low axial ratio without compromising overall antenna performance.