Wideband single-fed circularly polarised patch antenna

A novel circularly polarised (CP), single-fed microstrip antenna is presented. The antenna consists of a stacked structure of almost square patches. The proposed design has a reduced antenna size compared to the conventional CP microstrip antenna at a given operating frequency. The impedance and axial ratio bandwidths are large and CP radiation quality is excellent over the entire upper hemisphere. The proposed antenna is suitable for global positioning system (GPS) applications