A Compact Tri-Band Dual-Polarized Corner-Truncated Sectoral Patch Antenna

A coaxial probe-fed sector shaped patch antenna with the three corners truncated generates a triple band resonance by employing the higher order modes of the patch. A fourth sectoral indentation is used to tune the third band. The antenna is fabricated on an FR4 substrate of size 40 mm × 50 mm × 1.6 mm and experimentally investigated. The resonances cover the UMTS (1.92-2.17 GHz), WiMAX (3.3-3.6 GHz), and the ISM 5.2 (5.1-5.3 GHz) bands with 10 dB return loss bandwidths of 11.2%, 5.14%, and 3.9%, respectively, and 3-dB axial ratio bandwidth of 5.8% in the first band. The polarization is circular in the UMTS band and linearly orthogonal in the other two bands. The frequency ratio of the two linearly polarized bands is tunable in the range 1.39-1.51. Area reductions of 6.6% in the patch and 64% in the ground plane with respect to the work on disc sector patch antenna by Hsu et al. are obtained.