Horn Antenna Beam Scanning using Electronically Tunable Aperture Loading

In this paper we demonstrate antenna beam steering from a single X-band horn antenna whose aperture is loaded using an electronically tunable surface. The surface is a periodic array of electrically small, coupled resonators, a high-impedance surface. The transmission phase across the surface can be selectively varied by tuning the resonance frequency of the surface as a function of position. When positioned in the aperture of a horn antenna and excited by the antenna radiated field this phase gradient can be used to tilt the antenna far field pattern from 0° to 25°.