A monolithic microwave integrated circuit device provides a microwave transmission line with a resistor coupled thereto and a heating element thermally coupled to the resistor but electrically insulated therefrom by a dielectric layer. Heating the resistor with the heating element causes either a change in resistance of the resistor or the generation of noise by the resistor. Either the resistor or the heating element is constructed using monolithic integrated circuit construction techniques on the same circuit substrate with the transmission line.