High efficiency microwave lens

The electrical design of a high efficiency, constrained variable index of refraction, two point correction lens is described. The lens produces a 2.1 degrees azimuth beamwidth by a 2.7 degrees elevation beamwidth and is capable of being scanned more than 25 degrees either side of the lens axis. The variable index of refraction loading structures are discussed and the methods used to reduce lens surface reflections are described. Secondary radiation patterns and aperture efficiency of the experimental lens are presented for various angles of scan over a broadband.