An electronically steerable conformal antenna is disclosed. The antenna comprises a circuit board having a composite dielectric. The composite dielectric includes an array of a plurality of antenna elements disposed on the top surface and an array of tunable cavities, each tunable cavity disposed between an associated antenna element and a conductive ground plane on the composite dielectric's bottom surface. The composite dielectric also includes a conductor, extending from an antenna input through the composite dielectric and the tunable cavities and which forms a microstrip between each of the antenna elements.