Single/dual polarized filtering patch antennas without using extra circuits

In this paper, two kinds of filtering patch antennas without using extra filtering circuits are introduced, one for single-polarization and the other one for dual-polarization. The single-polarized antenna is composed of a stacked patch and a driven patch embedded with three shorting pins and a U-slot. A quasi-elliptic bandpass response with three radiation nulls generated by the stacked patch, shorting pins and U-slot in the boresight gain is achieved. The dual-polarized antenna consists of two orthogonal H-shaped feeding lines, a driven patch and a stacked patch. Also, a quasi-elliptic bandpass response with two radiation nulls provided by H-shaped line and stacked patch is achieved for the dual-polarized filtering antenna.