Abstract: An applicator comprising a generator of microwaves, said microwaves having a mode of propagation and a wavelength, an enclosure for receiving material to be treated, a coupler coupling the generator and the enclosure so that the generator delivers microwave energy distributed in resonance for said mode of propagation in a given direction, a first short-circuit device situated at one end of said enclosure with respect to said direction, a device for displacing the first short-circuit device by a reciprocating movement in said direction, and means for maintaining the resonance in spite of the displacements of the first short-circuit device.

Abstract: In a process for applying microwaves to a material, consisting in applying two beams from a single source to an inlet face of the material putting in phase, the beams reflected by the inlet face of the material superposing the two reflected beams to form a superposed beam, which is returned into the material, the improvement which consists in that the material is divided into two portions which are electromagnetically decoupled.