An antenna includes a dielectric substrate, a circular patch overlying the dielectric substrate, and a metamaterial ground plane. One or more antenna feeds are coupled to the circular patch. The antenna feeds may include impedance transformers. The metamaterial ground plane includes a plurality of conductive patches and a ground plane. The conductive patches are arranged along a first plane below the circular patch and are separated from the circular patch by at least the dielectric substrate. The conductive patches are arranged in a pattern that provides circular symmetry with respect to a center of the circularly polarized antenna. The ground plane is arranged along a second plane and is electrically coupled to at least a first portion of the conductive patches. One or more of the conductive patches and the ground plane are coupled to ground.