An antenna assembly including a planar antenna formed on a dielectric substrate and a frequency selective impedance surface formed on the substrate and at least partially surrounding the antenna. The frequency selective impedance surface receives surface waves propagating along the dielectric substrate generated by the antenna, where the impedance surface mitigates negative effects of the surface waves by converting the surface wave energy into leaky-wave radiation, and also possibly providing some control of the radiation gain pattern of the antenna. In one embodiment, the dielectric substrate is vehicle glass, such as a vehicle windshield.