Abstract: The invention relates to a receiver for microwave signals--either emitted by a body or reflected therefrom--capable of analyzing the polar distribution of the signal strength by measuring the strength of the incoming signal after it had been passed through a horizontal, polarizing filter disk with three distinct transmission regions. One region transmits the entire signal reflected from a planar mirror positioned substantially at 45 degrees to the horizon and rotated on a vertical axis; the second and third regions in the planar electro-optical filter are defined by parallel grid lines, formed by electrical conductors opaque to the reflected radiation and aligned in mutually orthogonal arrays in the two regions respectively, so that each grid alignment becomes transparent to one polarization of the radiation incident thereon.