Microwave devices based on tunable metasurfaces

In this review presentation we will discuss various possibilities to design tunable microwave devices using artificial impedance surfaces. In particular, we will present our recent results on modeling dense arrays of patches, strip meshes and mushroom-type tunable impedance surfaces. Analytical formulas for grid and surface impedances of penetrable and impenetrable surfaces for arbitrary incidence angles including complex angles allowed us to make extensive studies of surface waves along artificial surfaces and also waves in impedance waveguides. Parameters of surfaces necessary for effective control of the waveguide mode properties will be presented. Finally, we will discuss possible practical realizations of various tunable surfaces and particularities of modeling of different realizations.