Design of a Low-cost Broadband Dual-polarized Aperture-coupled Stacked Patch Antenna

This paper presents a wide-band aperture-coupled dual-polarized stacked microstrip patch antenna operating in the frequency range from 3.3 GHz to 4.2 GHz. The design starts with a single-polarization stacked-patch reference element, which is modified and extended to achieve a broadband design with dual polarization. The aperture and the feeding network of the antenna are manufactured on FR4 substrate to keep the costs and substrate height low. Dual polarization is achieved by using two perpendicularly arranged H-shaped apertures each of them excited by fork-shaped feed lines. Two stacked patches are placed on top of the 3D-printed material Visijet M3X and air gaps between the patches allow reducing the effective permittivity, avoiding the use of expensive and low permittivity thick materials. Broadband performance is realized by optimizing the dimension of the patches, the thickness of the 3D-printed material, the air gaps height and aperture dimensions. Four antenna elements are arranged into a single PCB to form a 2 × 2 array and a phase shift circuit is used to create different beam directions. Measurements show a return loss better than 10 dB over the specified bandwidth. A gain of 6.29 dBi and an efficiency of 80% are obtained. Simulations and measurements show a good agreement.