Numerical and experimental evaluation of spherical wave absorption incident on a thin metamaterial absorber

It has been proposed that a thin metamaterial absorber could be used for measuring 2-d RF field distributions incident on the absorber surface. The structure of the absorber consists of a matrix of dense metal patches formed on the surface of a thin grounded dielectric substrate. The incident wave power is absorbed by lumped resistors inserted between the surface patches, which are matched with incident wave impedance at the resonance frequency of the metamaterial structure. The incident field distribution can be monitored by measuring the voltages induced on (or the amounts of power consumed by) the lumped resistors.