A variable capacitor includes a substrate; a plurality of electrodes on the substrate; a phase change material on the plurality of electrodes; and a thermo-modifying element adjacent to the phase change material, wherein the thermo-modifying element changes a temperature of the phase change material. The change in temperature of the phase change material may change a capacitance between the plurality of electrodes. The thermo-modifying element may be integrated into the substrate. The thermo-modifying element may include a heater that raises a temperature of the phase change material to change from a solid state to a liquid state. The thermo-modifying element may include a layer of metal adjacent to the substrate, and wherein when electrical current flows through the layer of metal, the layer of metal forms a resistive heater and raises a temperature of the phase change material to change from a solid state to a liquid state.