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 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: 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: 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.