Salisbury screen with reduced angular sensitivity

A new Salisbury screen absorber design is presented, which yields a significantly reduced sensitivity to angle of incidence. This is achieved by using an artificial magnetic ground plane, which is designed to scatter the reflected signals in a conjugate phase relationship with respect to the change in the electrical spacing between the ground plane and the resistive screen. Numerical and experimental results in the range 8-12 GHz are used to demonstrate that scan compensation can be obtained over the angular range 0-40deg thus removing the shift in the resonant frequency that occurs in conventional Salisbury screen absorbers when operated off normal incidence.