Compact circularly polarized enhanced gain microstrip antenna on high permittivity substrate

A new combination of proximity coupled circular microstrip antenna and a square quasi-planar surface mounted short horn is proposed on the high permittivity substrate (ε_r= 10.2) to increase the gain of a compact circularly polarized patch by 4.46 dB. This antenna structure has gain 9.0 dBi and over 3 dB beamwidth (70°) the axial ratio (AR) is 0.11 dB. The AR bandwidth is 1.31%. The surface mounted horn provides flat gain over AR ratio bandwidth. The horn improves the side lobe level and the back lobe level between 7 dB to 10 dB. The patch structure has 12% area reduction over normal circular microstrip patch antenna. Total thickness of structure is only 13 mm.