Abstract: A microwave heating system includes: a variable-frequency microwave source having a usable bandwidth about a center frequency; a waveguide with an input side connected to the source and an output side terminating in a launch structure; and, a metallic reflector plate facing the launch structure and perpendicular thereto and spaced therefrom at a distance of no more than twice the microwave wavelength at an operative frequency of the microwave source, the reflector plate including a recessed area of a selected size and shape located facing the launch structure so that a material to be treated may be placed between the launch structure and the recessed area for exposure to microwave energy. A related method is also disclosed.

Abstract: A microwave heating device includes a variable frequency microwave power supply, a waveguide launcher, and a fixture to contain a material to be heated, with the fixture located directly adjacent to the end of the launcher. All heating occurs in the near-field region, i.e., no cavity modes or standing waves are established within the fixture. This condition may be insured by keeping the thickness of the fixture or workpiece under one wavelength (at all microwave frequencies being used). The launcher is preferably a horn configured to spread the microwave power laterally over a selected area while maintaining a single propagating mode. The invention may be used to enhance catalytic reactions for research and other purposes. Alternatively, the invention may be configured to perform spot curing or repair operations involving adhesives and composites.

Abstract: A microwave heating device includes a variable frequency microwave power supply, a waveguide launcher, and a fixture to contain a material to be heated, with the fixture located directly adjacent to the end of the launcher. All heating occurs in the near-field region, i.e., no cavity modes or standing waves are established within the fixture. This condition may be insured by keeping the thickness of the fixture or workpiece under one wavelength (at all microwave frequencies being used). The launcher is preferably a horn configured to spread the microwave power laterally over a selected area while maintaining a single propagating mode. The invention may be used to enhance catalytic reactions for research and other purposes. Alternatively, the invention may be configured to perform spot curing or repair operations involving adhesives and composites.

Abstract: A microwave heating device includes a variable frequency microwave power supply, a waveguide launcher, and a fixture to contain a material to be heated, with the fixture located directly adjacent to the end of the launcher. All heating occurs in the near-field region. This condition may be insured by keeping the thickness of the fixture or workpiece under one wavelength (at all microwave frequencies being used). The launcher is preferably a horn or waveguide configured to apply the microwave power to a small area to perform spot curing or repair operations involving adhesives and composites. The spot curing may secure components in place for further handling, after which a thermal or oven treatment will cure the remaining adhesive to develop adequate strength for service. A related method is also disclosed.

Abstract: A microwave heating system includes: a variable-frequency microwave source having a usable bandwidth about a center frequency; a waveguide with an input side connected to the source and an output side terminating in a launch structure; and, a metallic reflector plate facing the launch structure and perpendicular thereto and spaced therefrom at a distance of no more than twice the microwave wavelength at an operative frequency of the microwave source, the reflector plate including a recessed area of a selected size and shape located facing the launch structure so that a material to be treated may be placed between the launch structure and the recessed area for exposure to microwave energy. A related method is also disclosed.

Abstract: A microwave heating device includes a variable frequency microwave power supply, a waveguide launcher, and a fixture to contain a material to be heated, with the fixture located directly adjacent to the end of the launcher. All heating occurs in the near-field region. This condition may be insured by keeping the thickness of the fixture or workpiece under one wavelength (at all microwave frequencies being used). The launcher is preferably a horn or waveguide configured to apply the microwave power to a small area to perform spot curing or repair operations involving adhesives and composites. The spot curing may secure components in place for further handling, after which a thermal or oven treatment will cure the remaining adhesive to develop adequate strength for service.

Abstract: A microwave heating device includes a variable frequency microwave power supply, a waveguide launcher, and a fixture to contain a material to be heated, with the fixture located directly adjacent to the end of the launcher. All heating occurs in the near-field region. This condition may be insured by keeping the thickness of the fixture or workpiece under one wavelength (at all microwave frequencies being used). The launcher is preferably a horn or waveguide configured to apply the microwave power to a small area to perform spot curing or repair operations involving adhesives and composites. The spot curing may secure components in place for further handling, after which a thermal or oven treatment will cure the remaining adhesive to develop adequate strength for service. A related method is also disclosed.

Abstract: A microwave heating device includes a variable frequency microwave power supply, a waveguide launcher, and a fixture to contain a material to be heated, with the fixture located directly adjacent to the end of the launcher. All heating occurs in the near-field region, i.e., no cavity modes or standing waves are established within the fixture. This condition may be insured by keeping the thickness of the fixture or workpiece under one wavelength (at all microwave frequencies being used). The launcher is preferably a horn configured to spread the microwave power laterally over a selected area while maintaining a single propagating mode. The invention may be used to enhance catalytic reactions for research and other purposes. Alternatively, the invention may be configured to perform spot curing or repair operations involving adhesives and composites.

Abstract: A microwave heating device includes a variable frequency microwave power supply, a waveguide launcher, and a fixture to contain a material to be heated, with the fixture located directly adjacent to the end of the launcher. All heating occurs in the near-field region, i.e., no cavity modes or standing waves are established within the fixture. This condition may be insured by keeping the thickness of the fixture or workpiece under one wavelength (at all microwave frequencies being used). The launcher is preferably a horn configured to spread the microwave power laterally over a selected area while maintaining a single propagating mode. The invention may be used to enhance catalytic reactions for research and other purposes. Alternatively, the invention may be configured to perform spot curing or repair operations involving adhesives and composites.

Abstract: A microwave processing system includes: a broadband variable frequency microwave (VFM) source; a plurality of waveguide applicators, each of which includes a waveguide transition and is capable of supporting a selected subset of frequencies within the bandwidth of the broadband VFM source; a microwave switching means allowing the microwave source to be connected to any one of the waveguide transitions so that microwave power is delivered to the corresponding waveguide applicator; and wherein each of the waveguide applicators includes at least one channel through which a microwave transparent tube may be run so that process fluid flowing through the tube may be exposed to microwave power in the applicator.

Abstract: A microwave heating device includes a variable frequency microwave power supply, a waveguide launcher, and a fixture to contain a material to be heated, with the fixture located directly adjacent to the end of the launcher. All heating occurs in the near-field region, i.e., no cavity modes or standing waves are established within the fixture. This condition may be insured by keeping the thickness of the fixture or workpiece under one wavelength (at all microwave frequencies being used). The launcher is preferably a horn configured to spread the microwave power laterally over a selected area while maintaining a single propagating mode. The invention may be used to enhance catalytic reactions for research and other purposes. Alternatively, the invention may be configured to perform spot curing or repair operations involving adhesives and composites.

Abstract: A materials processing system comprises a thermal processing chamber and a broadband microwave power source. The power source includes an ovenized small-signal RF circuit, a high power microwave amplifier, and forward and reflected power detectors separated from one another by an isolator. The power detectors are also preferably ovenized. A control system provides control signals to the thermally stabilized VCO and VCA in the small-signal circuit to control output power based on detected forward power compared to demanded forward power. The system may be run in either open-loop or closed-loop modes.

Abstract: A microwave heating device includes a variable frequency microwave power supply, a waveguide launcher, and a fixture to contain a material to be heated, with the fixture located directly adjacent to the end of the launcher. All heating occurs in the near-field region. This condition may be insured by keeping the thickness of the fixture or workpiece under one wavelength (at all microwave frequencies being used). The launcher is preferably a horn or waveguide configured to apply the microwave power to a small area to perform spot curing or repair operations involving adhesives and composites. The spot curing may secure components in place for further handling, after which a thermal or oven treatment will cure the remaining adhesive to develop adequate strength for service. A related method is also disclosed.

Abstract: An apparatus for heating a semiconductor wafer includes: a microwave source; an applicator cavity; and, a fixture for supporting a wafer in the cavity. The fixture includes a dielectric mechanical support for the wafer and a grounded metallic ring movably positioned parallel to and concentric with the wafer at some distance from the wafer, to adjust the microwave power distribution to compensate for edge effects. A closed-loop feedback system adjusts the distance based on wafer edge and center temperatures. A method for heating a semiconductor wafer includes: a. placing the wafer in a microwave cavity; b. supporting the wafer on a fixture comprising a dielectric wafer support and a grounded metallic ring movably positioned at some distance from the wafer; c. introducing microwave power into the cavity to heat the wafer; and d. adjusting the distance between wafer and ring to modify the power distribution near the wafer edge.

Abstract: A microwave heating device includes a variable frequency microwave power supply, a waveguide launcher, and a fixture to contain a material to be heated, with the fixture located directly adjacent to the end of the launcher. All heating occurs in the near-field region, i.e., no cavity modes or standing waves are established within the fixture. This condition may be insured by keeping the thickness of the fixture or workpiece under one wavelength (at all microwave frequencies being used). The launcher is preferably a horn configured to spread the microwave power laterally over a selected area while maintaining a single propagating mode. The invention may be used to enhance catalytic reactions for research and other purposes. Alternatively, the invention may be configured to perform spot curing or repair operations involving adhesives and composites.

Abstract: A microwave processing system includes: a broadband variable frequency microwave (VFM) source; a plurality of waveguide applicators, each of which includes a waveguide transition and is capable of supporting a selected subset of frequencies within the bandwidth of the broadband VFM source; a microwave switching means allowing the microwave source to be connected to any one of the waveguide transitions so that microwave power is delivered to the corresponding waveguide applicator; and wherein each of the waveguide applicators includes at least one channel through which a microwave transparent tube may be run so that process fluid flowing through the tube may be exposed to microwave power in the applicator. A related method is also disclosed.

Abstract: An apparatus for thermal treatment of coatings on substrates includes a microwave applicator cavity; a microwave power supply to deliver power to the cavity; a thermally insulated microwave-transparent compartment within the cavity, large enough to contain the coated substrate while occupying no more than 50% of the total volume of the cavity; a means of supporting the coated substrate within the compartment; an adjustable IR heating source in the compartment and facing the substrate so that a selected amount of IR heating may be applied to the substrate; and, a non-contacting temperature measurement device to measure the temperature of the coating. Related methods for using the apparatus to process different kinds of films are also disclosed.

Abstract: An apparatus for heating a semiconductor wafer includes: a microwave source; an applicator cavity; and, a fixture for supporting a wafer in the cavity. The fixture comprises a dielectric mechanical support for the wafer and a grounded metallic ring movably positioned parallel to and concentric with the wafer at some distance from the wafer, to adjust the microwave power distribution to compensate for edge effects. A closed-loop feedback system adjusts the distance based on wafer edge and center temperatures. A method for heating a semiconductor wafer comprises: a. placing the wafer in a microwave cavity; b. supporting the wafer on a fixture comprising a dielectric wafer support and a grounded metallic ring movably positioned at some distance from the wafer; c. introducing microwave power into the cavity to heat the wafer; and d. adjusting the distance between wafer and ring to modify the power distribution near the wafer edge.

Abstract: An apparatus for heating a semiconductor wafer includes: a microwave source; an applicator cavity; and, a fixture for supporting a wafer in the cavity. The fixture contains a dielectric mechanical support for the wafer and a grounded metallic ring movably positioned parallel to and concentric with the wafer at some distance from the wafer, to adjust the microwave power distribution to compensate for edge effects. A closed-loop feedback system adjusts the distance based on wafer edge and center temperatures. A method for heating a semiconductor wafer includes: a. placing the wafer in a microwave cavity; b. supporting the wafer on a fixture having a dielectric wafer support and a grounded metallic ring movably positioned at some distance from the wafer; c. introducing microwave power into the cavity to heat the wafer; and d. adjusting the distance between wafer and ring to modify the power distribution near the wafer edge.

Abstract: A materials processing system comprises a thermal processing chamber and a broadband microwave power source. The power source includes an ovenized small-signal RF circuit, a high power microwave amplifier, and forward and reflected power detectors separated from one another by an isolator. The power detectors are also preferably ovenized. A control system provides control signals to the thermally stabilized VCO and VCA in the small-signal circuit to control output power based on detected forward power compared to demanded forward power. The system may be run in either open-loop or closed-loop modes.