Dual polarized microstrip patch antenna, reduced in size by use of peripheral slits

A two-port, meaodered, square, microstrip patch antenna is investigated in this paper. Forty slits are considered on the perimeter of a square patch, ten on each side, to reduce the operating frequency. Calculated and measured results manifest that (a) the gain, the radiation patterns (CO-a nd cross-polar), and the matching microstrip lines are practically unaffected by the peripheral slits, (h) the return loss at both ports is well below -2OdB, and (e) the coupling between ports is below -29dB. A square patch, thus meandered, may be up to 48% smaller in area than a square patch without slits, both with the same operating frequency.