US Patent 7626547 Embedded planar antenna with pertaining tuning method

A patch antenna comprising an electrically conductive ground plane; a first dielectric substrate layer arranged on said ground plane and having a first relative permittivity; at least one electrically conductive effective area arranged on the first dielectric substrate layer and electrically connected to one end of an electrically conductive feed line; at least one second dielectric substrate layer arranged on the effective area and having a second relative permittivity; whereby the second relative permittivity is larger or equal the first relative permittivity.