Abstract: A new type of microwave applicator has been disclosed. The applicator according to an embodiment of the invention makes use of an evanescent main power-transferring mode. This evanescent mode is complemented by a second mode, which is a propagating mode that has the purpose of providing a counter-directed magnetic field in the y-direction at the horizontal, y-directed applicator wall opening. The effect of the cooperation of the two applicator modes is that the field pattern extends over a significant distance below the applicator opening, such that a load placed below the applicator opening is heated by a field pattern of the mode combination.

Abstract: A rectangular microwave applicator operating at a predetermined frequency and comprising a microwave enclosure forming a cavity having first and second transverse dimensions and a longitudinal dimension n the direction of propagation of microwave energy, wherein said dimensions are such that a main power-transferring Teym1n mode with a long vertical wavelength is enhanced, and a significant amplitude of a complementary Teym2n mode is created, wherein m1, m2 and n are positive odd integers and m2 and n are both less or equal to m1-2.

Abstract: An assembly for applying microwave irradiation to a load having a generally circular cross-section. The applicator supports a dominant TM.sub.120 mode and the load is aligned with a central axis in the applicator, with each aperture of a pair of feed apertures diametrically opposed (for the circular cross sectional case) or located on parallel opposed walls (for the polygonal cross sectional case) with one of the pair of feed apertures positioned at 90 degrees with respect to the other pair about the axis. The applicator may be formed as a cylinder or as a polygonal prism of the type having parallel opposed sides, such as those having a square, hexagonal or octagonal cross-section. Means such as a microwave transparent tube or conveyor provide for positioning of the load in the applicator. In an alternative embodiment, two cavities are used, with one cavity associated with each of the two feed systems, and a means for conveying the load from the first cavity to the second cavity is provided.

Abstract: A microwave applicator of microwave reflective material having a closed first end, four side walls and, in a first embodiment, an open second end spaced apart from and facing a ground plate, the ground plate extending in a pair of transverse directions and having a longitudinal direction perpendicular thereto, and in a second embodiment, a closed second end, the applicator forming a cavity containing a desired hybrid mode having a low wave impedance in the longitudinal direction and an absence of an E field component in one of the transverse directions.

Abstract: A microwave applicator including a generally cylindrical microwave containment chamber, a microwave energy source, and a feed structure connecting the microwave energy source to the containment chamber. The diameter of the containment chamber is designed according to a process that need only take into account supporting a microwave pattern having substantially only two transverse magnetic modes, each with a characteristic guide wavelength, where the guide wavelength of one mode is substantially equal to twice the guide wavelength of the other mode. Additionally, the interior diameter can be sized to minimize the index subscript numbers of the transverse magnetic modes. The feed structure of the applicator includes at least two feed apertures spaced physically apart around the cylindrical axis of the applicator by a physical angle equal to an electrical phase shift angle of the microwaves introduced through the respective apertures, which in a preferred embodiment is 90 degrees.

Abstract: A dielectric heating applicator has a low-loss dielectric with a dielectric constant exceeding that of the object to be heated by microwaves. An internal resonance is excited in the applicator, which may consist of one or several parts, each containing dielectric, so that a specified field pattern exists at and in the object. Another characteristic is that the part of the object being heated has dimensions which are considerably less than one vacuum wavelength corresponding to the frequency used.

Abstract: A microwave heating apparatus for heating disc-shaped loads of variable water content wherein the energy is introduced by way of a sonde antenna connected to a coaxial cable, the disc-shaped load is positioned at the axial center of the chamber, and the apparatus is dimensioned to produce TO011 wave patterns, TM010 wave patterns, or a combination thereof, depending upon the dielectric constant of the load. The positioning means for the load may be connected to an external balance for continuously weighing the load.