Design of a simple dual polarized patch antenna for the base station application

Abstract

A dual-polarized patch antenna with a simple structure is proposed. The centre operating frequency of the antenna is 0.89 GHz and it is suitable for use in base stations. The antenna consists of two parts. The first part consists of two rectangular-shaped aluminum walls which are located between two L-shaped probes for the improvement of isolation. The second part is a square-shaped patch which is sustained by the plastic pillars in the air. The height of patch is about 0.1 free space wavelength at 0.89 GHz. Both simulation and measurement results showed that within the band 0.82-0.96 GHz, the return loss for both ports are less than -14dB. The simulated and measured isolation are closely matched to each other, which are both more than 30 dB within the aforementioned bandwidth. The radiation pattern for each input port of this antenna accomplishes cross-polarization level of less than -15dB over the pass band. The peak gains of port 1 and port 2 are both more than 7dBi. An additional study on the circularly polarized patch antenna has been done. The simulated axial ration is less than 3 dB.