A Deployable Wideband Differential-Fed Dual-Polarized Patch Antenna Array

In this paper, a deployable wideband differential-fed dual-polarized high-isolation patch antenna array is proposed. To achieve dual polarization, every element has two pairs of differential ports. Because of the differential design, the couplings from the adjacent ports (the other pair of ports) are canceled and high isolation between the two polarization is achieved. In addition, capacitive feeds are applied to enhance the bandwidth. By integrating with two planar Marchand baluns, the two pairs of the differential ports are excited for dual polarization. Then, the wideband dual-polarization patch antenna element is expanded to a 4x4 antenna array for better gain. In order to achieve deployment, we present a novel foldable mechanism suitable for low-frequency patch antenna array, which is different from the conventional design on the flexible printed board. The deployment concept is presented. One prototype is fabricated and measured. Its operating band is from 1.15 GHz to 1.35 GHz. The peak gains of the two polarizations are 14.4 dBi and 14.1 dBi respectively.