Dual-band dual-polarized compact planar monopole antenna for wide axial ratio bandwidth application

In this article, a geometrically simple, microstrip line-fed planar monopole structure with slanting edge ground plane is designed to realize the dual-band dual-polarized operation. The proposed antenna consists of a rotated U-shaped patch and an electromagnetically coupled L-shaped parasitic radiating element. Owing to the combination of microstrip line-fed radiating patch and a slanting-edge rectangular ground plane on the opposite side of the substrate, the proposed dual-band antenna can generate broad axial ratio bandwidth (ARBW) in the upper frequency band. The overall dimension of the prototype is only 32 x 32 x 1.6 mm(3). The measured results validate that the proposed antenna has two operational frequency bands, 29.84% (1.54-2.08 GHz) for linearly polarized radiation and 71.85% (3.96-8.4 GHz) for circularly polarized radiation. Measured result shows that 3-dB ARBW of the proposed antenna is 73.54% (3.80-8.22 GHz) in the higher frequency band. It shows that the higher frequency band exhibits a left-hand circularly polarized radiation in the boresight direction.