Polarizer reflector and reflecting plate scanning antenna including same

Claim 1

A wide band-width reflecting plate type antenna, comprising feeder means for feeding electromagnetic radiation; a front reflector disposed in front of the feeder means and illuminated by the electromagnetic radiation fed therefrom; and a back reflector disposed behind the front reflector for receiving the electromagnetic radiation reflected from the the front reflector and for producing a reflected beam which is polarized at a right angle to the incident electromagnetic radiation received from the front reflector; characterized in that said back reflector includes a reflecting layer, and a polarizer on the side thereof facing said front reflector, which polarizer includes means effective to convert substantially the entire energy of the incident electromagnetic radiation during its propagation forwardly through the polarizer to the reflecting layer, from linear polarization to circular polarization, and to reconvert substantially the entire energy of the electromagentic radiation reflected from said reflecting layer, during its propagation back through the polarizer, from circular polarization to linear polarization, but at a right angle to the incident electromagnetic radiation and whereby the phase delay between the polarizer and the reflecting layer does not affect the predetermined angle of rotation which is defined solely by the polarizer and wherein consequently the rotation through the predetermined angle takes place over a relatively wide band of frequencies.