Dual polarized triple wideband circular microstrip antenna for GSM and satellite applications

Abstract

Dual polarized triple frequency wideband design of circular microstrip antenna using the combination of slots and stub is proposed. This triple wideband response is explored by using a thinner substrate in the air suspended configuration that enables the input impedance matching at various higher order resonant modes together with the fundamental mode. Amongst different variations, modifications in terms of the slots and stubs degenerates and optimizes the spacing in between the fundamental and higher order modes, which leads to dual polarized wideband response. On air suspended FR4 substrate with thickness of 0.055λg, optimized single patch configuration yields dual polarized triple wideband response at 856, 1177, and 1783 MHz respectively giving frequency ratio of 1:1.37:2.0. It yields impedance bandwidth of 8.4%, 11.5%, and 11.4% at the three frequencies with respective broadside gain of 7.4, 6.5, and 3.5 dBi. The proposed configuration yields frequency and polarization agility satisfying the requirements of GSM850/navigation satellite/GSM 1800 applications.