Wideband dual-polarized planar antenna for base stations

A broadband dual-polarized planar antenna with simple reflector is introduced. The antenna is composed of two pairs of circular slotted square arms which are coupling-fed by two fan-shaped microstrip lines. By properly adjusting the feeding structure, the antenna can be connected to 50- coaxial lines directly, making the antenna full planar. Due to the fan-shaped microstrip stub and the tight coupling between the two dipoles, a bandwidth of 48.2% (1.62-2.68 GHz) for Return Loss>14 dB and sufficient high port-to-port isolation of 30 dB can be achieved simultaneously. Circular holes are introduced to elongate the current path, leading to a compact and light-weight radiator structure (0.36(0) x 0.36(0), where (0) refers to the center operating frequency) which contributes to a simple reflector. Besides, the measured results show that a stable half-power beam width of 70 degrees +/- 3 degrees, an average gain of 7.6 +/- 0.3 dBi for slant +/- 45 degrees polarizations, and a low cross-polarization of 29 dB are realized. (c) 2015 Wiley Periodicals, Inc. Microwave Opt Technol Lett 57:1948-1952, 2015