Dual-polarized high-selectivity filtering antennas without extra circuits

Abstract

This paper presents a novel kind of dual-polarized patch antennas with high-selectivity and low cross-polarization performance. The proposed antenna is mainly composed of a feeding network, a driven patch and a stacked patch. The feeding network consists of two orthogonal H-shaped lines that coupled to the driven patch, each for one polarization. The H-shaped lines ensure a sharp roll-off rate at the lower band-edge, the upper stacked patch provides improved suppression levels at the upper stopband. Consequently, a dual-polarized antenna with satisfying filtering performance is obtained, without using extra filtering circuits. Moreover, the operating bandwidth can be easily controlled while maintaining the filtering and radiation performance stable. For demonstration, two antennas are implemented with different bandwidths (2.49–2.70 GHz and 2.30– 2.70 GHz). The two antennas achieve an average gain of 9 dBi within passband, and out-of-band suppression levels of more than 40 dB in the lower stopband.