A reaction chamber contains catalytic material(s). Tunable microwave source(s) each emit microwave radiation at corresponding time-varying microwave frequency(ies) or at simultaneous multiple different microwave frequencies. Microwave transmission element(s) irradiate the interior volume of the reaction chamber with the microwave radiation, emitted by the microwave source(s), that propagates along the transmission element(s) into the reaction chamber. The reaction chamber is characterized by a maximum temperature variation of a fixed-frequency, steady-state temperature spatial profile that results from irradiation of the reaction chamber by microwave radiation at a substantially fixed microwave frequency and at a reference microwave power level. Irradiation of the reaction chamber at the reference microwave power level by the microwave radiation with the time-varying microwave frequency(ies), or the simultaneous multiple different microwave frequencies, results in a multi-frequency temperature spatial profile having a maximum temperature variation less than the maximum temperature variation of the fixed-frequency, steady-state temperature spatial profile.

An elementary device of the present disclosure includes a coaxial applicator that includes a connector disposed at a distal end of the applicator, a shielding, a microwave energy propagation medium disposed between a central core and the shielding, and an insulating body disposed at a proximal end of the applicator. The shielding surrounds the central core and has a bottom wall provided at the distal end. The connector includes an external conductor connected to the shielding and an internal conductor connected to the central core. The connector is disposed at the bottom wall with the external conductor fixed to the bottom wall and the internal conductor linked to a connecting element that extends through the bottom wall and parallel to the main axis with a predefined spacing provided between the central core and a free end connected to the central core at a predefined distance from the bottom wall.

A microwave system has a solid-state generator which generates microwave energy and includes at least one control input for receiving a control signal to vary electrically a parameter of the microwave energy. A microwave load receives the microwave energy and produces an effect in response to the microwave energy. A microwave conducting element couples the microwave energy to the microwave load. An impedance match adjusting device is coupled to the microwave conducting element to vary at least one of the parameters of the microwave energy. The effect produced in response to the microwave energy is altered by both electrical variation of the parameter of the microwave energy via the control signal and adjustment of the impedance match adjusting device to vary the parameter of the microwave energy.

An elementary device of the present disclosure includes a coaxial applicator that includes a connector disposed at a distal end of the applicator, a shielding, a microwave energy propagation medium disposed between a central core and the shielding, and an insulating body disposed at a proximal end of the applicator. The shielding surrounds the central core and has a bottom wall provided at the distal end. The connector includes an external conductor connected to the shielding and an internal conductor connected to the central core. The connector is disposed at the bottom wall with the external conductor fixed to the bottom wall and the internal conductor linked to a connecting element that extends through the bottom wall and parallel to the main axis with a predefined spacing provided between the central core and a free end connected to the central core at a predefined distance from the bottom wall.

A semiconductor microwave oven and a microwave feeding structure thereof are provided. The microwave feeding structure of the semiconductor microwave oven includes: a chamber body having a door; a semiconductor power source configured to generate a microwave; and a microwave feeding assembly connected between the semiconductor power source and the chamber body, and configured to feed the microwave generated by the semiconductor power source into the chamber body and to convert a first microwave mode output by the semiconductor power source into a second microwave mode adaptive to microwave heating.

A method for managing a microwave heating device able to operate based on a first signal having a first fundamental harmonic frequency that is within the microwave range, wherein operation of the microwave heating device (1) is interrupted or modified when, inside the microwave heating device (1), the presence of a second signal is detected, the latter having harmonic components which have frequencies that are different from a fundamental harmonic frequency and an intensity higher than a critical reference value.

A microwave processing device includes: a periodic structure body which forms a surface-wave transmission line to transmit surface waves of microwaves; an oscillator which generates microwave power; and a transmitting part which transmits the microwave power generated by the oscillator to the periodic structure body, wherein a matching part is provided at a connecting portion between the periodic structure body and the transmitting part, and an impedance of the matching part is set to a value between an impedance of the periodic structure body and an impedance of the transmitting part.

The invention relates to a device for the heating a functional layer of coating material, such as a surface coating or an edge strip, in particular for applying the coating material onto an area of a workpiece, comprising a microwave source, an applicator and a microwave channel for supplying the microwave radiation generated in the microwave source to the applicator, wherein a microwave field is generable in the applicator on account of the supplied microwave radiation, wherein the applicator has at least one material channel, which passes through the applicator and through which the coating material can be fed such that the functional layer of the coating material is heated in the microwave field within the applicator.

A microwave heating device includes: a heating chamber for accommodating a heating target object, a microwave generator for generating a microwave, and a coaxial connector. The coaxial connector includes a center conductor, an insulator, and an external conductor. The center conductor is connected to an output terminal of the microwave generator. An air gap is defined between the center conductor and the insulator.

A reaction chamber contains catalytic material(s). Tunable microwave source(s) each emit microwave radiation at corresponding time-varying microwave frequency(ies) or at simultaneous multiple different microwave frequencies. Microwave transmission element(s) irradiate the interior volume of the reaction chamber with the microwave radiation, emitted by the microwave source(s), that propagates along the transmission element(s) into the reaction chamber. The reaction chamber is characterized by a maximum temperature variation of a fixed-frequency, steady-state temperature spatial profile that results from irradiation of the reaction chamber by microwave radiation at a substantially fixed microwave frequency and at a reference microwave power level. Irradiation of the reaction chamber at the reference microwave power level by the microwave radiation with the time-varying microwave frequency(ies), or the simultaneous multiple different microwave frequencies, results in a multi-frequency temperature spatial profile having a maximum temperature variation less than the maximum temperature variation of the fixed-frequency, steady-state temperature spatial profile.