A broadband positioning array antenna with crescent-like slits for global navigation satellite system applications

A broadband positioning 2×1 rectangular patch array antenna, loaded with crescent-like slits near corner as phase control units, is proposed for GPS and Beidou applications. The proposed antenna consists of two ortho-placed square radiation patches, which provide the antenna with a wider band of circular polarization. Near the corners of the patches, each radiation edge is loaded with a crescent-like slit, which is paired of another slit on the perpendicular radiating edge of the rectangular patch. The phase difference between orthogonal radiation edges and their radiation patterns could be controlled. The dimensions of all the slits and the distances from the slits to the edges are discussed to explain the effect of the slits on the resonant frequencies. The array antenna is feeding by a microstrip Wilkinson splitter on the back. Simulated and measured results show that the designed antenna has good return loss characteristics and a circular polarization within the desired operating bands, with the operating frequencies covering both L2 GPS band and B2 Beidou band for the requirements of these two satellite positioning systems.