A T-junction microwave applicator and a method for making a T-junction microwaveapplicator with a microwave source supplying electromagnetic energy througha junction arm to a pair of collinear arms extending in opposite directions fromtheir junction with the junction arm. The two collinear arms form a main waveguideterminated in end walls in which entrance and exit ports are formed for a conveyorto convey material to be heated through the main waveguide for exposure to electromagneticenergy. A rectangular conductive ridge in the wall of the main waveguide oppositethe junction arm extends the length of the applicator. A cylindrical tuning barspanning the junction is positioned vertically in a plane perpendicular to theaxis of the main waveguide to maximize power transfer to the material to be heated.
