Thin absorbing structure for all incidence angles based on the use of a high‐impedance surface

It is shown that thin mushroom layers (high‐impedance surfaces realized as regular arrays of small patches at a small distance from a metal surface) can be used as radar‐absorbing structures whose performance does not change with the incidence angle for TM‐polarized waves. The key role of the vias connectors between the patches and the ground plane is explained, and potential performance demonstrated in examples.