A 4-element sub-array with 4-polarization modes

Abstract

A 4-element 2×2 sub-array based on patch antennas operating at 3.6 GHz is proposed. The sub-array can provide 4 polarizations. The design consists of two substrates (RO4350B) with 8r = 3.66 with heights of 1.524 mm and 0.762 mm for the top and bottom layers respectively. The investigated technique required adding two orthogonal slots inside the patch to allow placing PIN diodes and their connection to the biasing circuitry which is located at the bottom layer. This model provides four types of antenna polarization which are left-handed circular polarization (LHCP), right-handed circular polarization (RHCP) and two cases of linear polarization (LP_ON and LP_OFF). The maximum obtained gain was 9.63 dB and the bandwidth was 145 MHz.