A low-profile, dual-polarized, and wideband square cavity-backed antenna

A cavity-backed antenna with low-profile, dual-polarization, and wide operating bandwidth characteristics is proposed. In this design, two orthogonally positioned triangular bowtie antennas printed on a low-cost substrate are loaded onto a square cavity, so that two orthogonal linear polarizations can be excited. By further introducing four extended ground stubs from each side of the square cavity, the proposed antenna can also acquire low-profile characteristic of approximately 0.1λ (15 mm). To achieve good impedance matching, additional circular slots are introduced into each bowtie design. The measured results show that the proposed antenna can cover a wide operating bandwidth of 62% (2.0–3.8 GHz) with a VSWR of 2:1. Besides exhibiting good isolation (>20 dB) between the two feeding ports, desirable realized gains (6.0–10.5 dBi) over the wide operation band are also demonstrated.