US Patent 11264728 Cross-polarization antenna filter

Disclosed are devices and methods for selecting, at an antenna reflector, electromagnetic waves with a certain polarization and frequency and rejecting electromagnetic waves with different polarizations and/or frequencies. In one aspect, a directional antenna includes a shaped reflector surface with a series of conforming layers attached to the surface. The layers include a reflecting layer that causes reflection of electromagnetic waves at a specific frequency and polarization. Underneath the reflecting layer is a frequency selective surface (FSS) layer that absorbs electromagnetic waves not at the specific frequency or polarization which pass through the reflecting layer. Underneath the absorbing layer is a conductive layer.