US Patent 9583840 Microwave zoom antenna using metal plate lenses

A zoom antenna includes an ordinary pyramidal horn antenna with either a coaxial or waveguide feed and two parallel plate waveguide lenses (commonly referred to as “metal plate lenses”) positioned with their optical axes collinear with the boresight of the pyramidal horn antenna and aligned with their plates parallel to the electric field vector. The zoom antenna outputs a collimated microwave beam having a diameter varied by translation of the lenses along boresight relative to each other and relative to the phase center of the horn antenna. The zoom antenna can be rotated to vary the azimuth and elevation angles of the collimated microwave beam produced therefrom, to thereby aim the beam in any direction.