Patent attributes
A switchable dual polarization patch antenna with improved cross polarization isolation to concurrently radiate horizontally polarized signals and vertically polarized signals. A planar conductor is arranged with a first terminal and a second terminal that are vertically spaced on a portion of the planar conductor to radiate a component of a vertically polarized signal with zero degrees of phase shift from one of the two terminals and radiate another component of the vertically polarized signal having a 180 degrees of phase shift from the other of the two terminals. A hybrid coupler can provide the 180 degrees of phase shift. A horizontally polarized signal is radiated from a third terminal that is horizontally spaced on another portion of the planar conductor and coupled to a horizontally polarized signal source. The direction of the 180 phase shift for the first and second components of the vertically polarized signal may be selected. Also, a direction for a phase shift for the horizontally polarized signal may be selectable.