A New Differential Dual-Polarized Filtering Microstrip Patch Antenna Without Extra Circuit

A new differential dual-polarized filtering microstrip patch antenna without extra circuit is proposed. The presented antenna is simple, symmetrical and compact, where a pair of crossed feeding line is symmetrically embedded in a circular patch. Thus, the circular patch can be divided into four identical quarter circular patches which functions as radiators as well as resonators. In addition, a very thin air layer is embedded between the substrate and the ground plane to acquire better impedance matching and higher antenna gain. For both polarization, without any extra filtering circuit, three radiation nulls (RNs) can be generated near the passband. The antenna prototype is simulated, in which great performance can be obtained. The proposed antenna features high gain, high polarization isolation, low cross-polarization level, wideband and excellent filtering performance, simultaneously. It is a good candidate for wireless communication application.