Performance enhancement of Salisbury screen absorber using a resistively loaded high impedance ground plane

In this paper we use numerical predictions to show that a Salisbury screen absorber backed by a high impedance ground plane can be designed to give a −10 dB reflectivity bandwidth which exceeds 100% when operated at angles of incidence up to 40º. The structure consists of a periodic array of lossy dipoles which is sandwiched between the ground plane and the resistive screen. A major advantage of this design methodology is that the enhanced bandwidth performance and insensitivity to angle of incidence is obtained without the need to increase the physical thickness of the structure. The reflectivity predictions over the frequency range 5.38–18 GHz are shown to be in good agreement with experimental results for normal and oblique angles of incidence up to 40°.