Wideband polarization-agile planar microstrip patch array antenna

A planar polarization-agile printed antenna consisting of four corner-fed stacked patches suitably connected to a central aperture-coupled stacked patch to form a five-of-dice array configuration is presented. The excitation is dispensed to the whole array through the element at the centre, which is directly coupled to a pair of open-stub ended microstrip lines by a cross-shaped aperture. As a result, polarization agility operation can be achieved by using a single phase-switching circuit to deliver appropriate input signals at the antenna ports. The design concept is described and its potential is discussed on the basis of the simulation results obtained by the Method of Moments (MoM). In particular, two different antenna configurations featuring either a single- or a double-layer feed network to most favour simplicity of construction or polarization purity are investigated.