An antenna has radio-frequency (RF) antenna elements and two substrates. A heater structure is connected to at least one of the two substrates, for heating the RF antenna elements. In one embodiment, the antenna comprises: a physical antenna aperture having an array of radio frequency (RF) antenna elements formed with patch and iris substrates, the iris substrate having a plurality of layers including an iris metal layer; and a heater structure coupled to one or more of the plurality of layers of the iris substrate for heating the RF antenna elements.