Nonlinear, active, and anisotropic impedance surfaces

Artificial impedance surfaces, a type of planar metamaterial, have the potential to provide new capabilities that are not possible with homogeneous RF materials, and are more practical than conventional metamaterial approaches for RF applications. By adding active electronics, nonlinear devices, and new types of anisotropic patterns, we can enable new capabilities such as controlling the flow of surface currents over metallic objects, absorbing high power microwave energy using nonlinearity, manipulating the interaction between waves and materials based on power level or waveform, and new practical approaches to cloaking surface features. This talk will discuss the use of passive anisotropic surfaces for controlling scattering effects. We will also discuss our recent work in nonlinear surfaces in which we have demonstrated the first example of waveform dependent absorption. We will also discuss our use of nonlinearity to demonstrate self-focusing in artificial impedance surfaces.