Microwave Beam Steering Reflector Based on a Tunable Impedance Surface

We describe a new kind of beam steering reflector consisting of a textured surface covered with an array of tiny resonators. The surface is mechanically tuned using a motion of only 0.01 wavelength. By individually tuning the resonators, the effective impedance of the surface, and thus the microwave reflection phase, can be varied. By configuring the surface with a reflection phase gradient, it can steer a reflected beam by as much as +/-38°. The concept is also amenable to electrically tunable structures, which can provide faster steering, and greater functionality.