A Proximity-coupled Dual-band Orthogonal-polarized Filtering Antenna Array

A novel dual-band orthogonal-polarized filtering antenna array is proposed by utilizing proximity-coupled microstrip feed in this paper. Independent patches with different sizes are designed to implement dual-band orthogonal-polarized radiation, which ensures the good isolation property. U and L resonators are introduced into the series-feeding network, so that two separated arrays can be fed by only one open-circuit microstrip line. Proximity-coupled feeding mechanism also ensures the moderate bandwidth. Good bandpass responses with high frequency selectivity are achieved simultaneously over dual-band. A 2-element orthogonal-polarized array operating at 4.5GHz and 5.0GHz is designed. The bandwidths of 3.8 percent and 4.4 percent, high gain of 7.5dBi and 8.0dBi and good bandpass property have been achieved in the two bands, respectively. Isolation between two operating bands is quite good. Because of the simple feeding network, this small array can easily be expanded into large arrays.