Dual-Band Dual-Polarized Patch Antenna Using Characteristic Mode Analysis

In this research, a novel dual-band triangular patch antenna (TPA) with linear-orthogonal polarization is designed by utilizing degenerate modes (DMs). Current symmetries of fundamental DMs of TPA are exploited to achieve dual-band antenna operation. An equilateral triangular slot is inserted along one of the edges to separate resonant frequencies of DMs and simultaneously exciting them at different resonant frequencies. The location of the slot is chosen according to the current symmetries of the horizontal mode to elongate its current paths and moving it to a lower resonant frequency while keeping vertical mode at its fundamental resonant frequency. The prototype of the proposed single probe-fed antenna is fabricated and tested. The designed antenna exhibits low frequency ratio (FR) and broadside radiation patterns with gains of 4.96 and 6.10 dBi in the first and second bands, respectively. Low cross-polarization levels and linear-orthogonal polarization are achieved in both bands.