Stacked rectangular ring antenna for GPS mobile receiver

A microstrip patch antenna array for use with the GPS receiver has been developed. The paper presents microstrip stacked rectangular-ring patches with low cross polarisation over an extremely wide beamwidth (close to hemisphere). The desegmentation technique (multiport network modelling coupled with cavity model), providing a detailed equivalent network representation of microstrip patches, mutual coupling among them, and the probe feed of an array has been used. It is a convenient framework for CAD of microstrip patch antennas composed of regular (rectangular, circular, elliptical, etc.) shape parts. The antenna operates at the two frequencies of the GPS signal with an axial ratio less than 3 dB over and angle 140 degrees and VSWR less than 1:1.5 over 20 MHz bandwidth centred on each band.