Designing and building of a circular GPS antenna

A circularly polarized microstrip antenna for global positioning system aims is proposed. This work presents the design of a dual-feed patch, which operates at single band (L₁) of 1575 MHz. Circular polarization is achieved directly by the dual-feeding technique of a square patch through microstrip lines. The geometrical emplacement of the lines and the feeding point had been chosen in such a matter for the generated waves to be ninety degrees out of phase. The antenna is matched for 50 ohm input impedance, with 1.3% matching bandwidth and 0.63% right-hand circular polarization bandwidth. Good agreement between simulation and measurement was achieved.