A microwave heating device with reflection protection belongs to a technical field of microwave applications. A first port of a circulator is connected to a microwave generator, and a second port of the circulator is connected to a microwave transmission device. A water load comprises a waveguide section, a metamaterial structure layer and the absorption tube. One end of the waveguide section is connected to a third port of the circulator, and the other end is sealed by a metal plate. The metamaterial structure layer is arranged in the waveguide section, and a center of the metamaterial structure layer has an accommodation space. The absorption tube is arranged along an internal wall of the accommodation space with a spiral extending form. Both ends of the absorption tube penetrate the waveguide section, and coolant flows in the absorption tube. Relative dielectric constants of the metamaterial structure layer gradually increase.

A defrosting system includes an RF signal source, one or more electrodes proximate to a cavity within which a load to be defrosted is positioned, a transmission path between the RF signal source and the electrode(s), and an impedance matching network electrically coupled along the transmission path between the output of the RF signal source and the electrode(s). The system also includes measurement circuitry coupled to the transmission path and configured to measure one or more parameters that include voltage, current, forward signal power, reflected signal power, and S11 along the transmission path. A system controller is configured to monitor the measurements, and to modify operation of the system when a rate of change of any of the monitored parameter(s) exceeds a predetermined threshold. The impedance matching network may be a single-ended network or a double-ended network.

A microwave heating apparatus and methods of controlling cooling of a microwave heating apparatus are provided. The microwave heating apparatus typically includes a microwave source for generating microwaves, a cooling unit for cooling the microwave source and a control unit. According to one embodiment, the control unit is configured to receive operational data from a measuring device indicative of the measured power of microwaves transmitted from the magnetron and receive operational data from the measuring device indicative of the measured anode current of the magnetron. A calculating device calculates an efficiency of the magnetron as a function of the measured power of the transmitted microwaves and the measured anode current, to define a determined efficiency. The control unit controls the cooling unit and cools the magnetron based on the determined efficiency.

A combination microwave and refrigerator system is provided. The microwave oven is connected to a source of power and has at least one control circuit for controlling the operation of the microwave oven. A first power supply outlet is provided on the microwave oven. A refrigerator is connected to the source of power by connection to the first power supply outlet. The control circuit is configured to disable the cooling operation of the refrigerator, when the microwave oven demands cooking power, and enable the cooling operation of the refrigerator when the microwave oven is not drawing cooking power. A safety sensor is provided in the microwave oven, and is configured to cause cooking power to the microwave oven to be turned off upon the safety sensor sensing smoke or other conditions.

A combination microwave and refrigerator system is provided. The microwave oven is connected to a source of power and has a control circuit for controlling the operation of the microwave oven. A first power supply outlet is provided on the microwave oven. A refrigerator is connected to the source of power by connection to the first power supply outlet. The control circuit is configured to disable the cooling operation of the refrigerator, when the microwave oven demands cooking power, and enable the cooling operation of the refrigerator when the microwave oven is not drawing cooking power. A safety sensor is provided in the microwave oven, and is configured to cause cooking power to the microwave oven to be turned off upon the safety sensor sensing a dangerous condition.

A system for applying microwave energy to a product in which a conveyor extends through a central portion of a cavity having a pair of opposing sidewalls. The conveyor is supported directly or indirectly by a plurality of support elements attached to and between the sidewalls. The system includes top and bottom waveguides directing microwave energy toward the conveyor, and provides for attachment blocks surrounding the support elements and fastened to a support sheet on which the conveyor is conveyed. Contact strips can be used to reduce conveyor friction.

An apparatus and a method for heating a load using microwaves is disclosed. The apparatus includes a transmission line, configured to transmit microwaves from a microwave generator to a cavity. A sensing device configured to measure a standing wave for providing information about the phase and the amplitude of a reflection coefficient that represents a ratio between the amount of microwaves reflected back towards the microwave generator and the amount of microwaves transmitted in the transmission line from the microwave generator. A control unit configured to detect whether the measured standing wave correspond to a reflection coefficient having a phase within a certain interval of phases and an amplitude within a certain interval of amplitudes. Additionally, certain intervals of phases and amplitudes correspond to an operating region of the microwave generator. The control unit controls feeding of microwaves to the cavity based on this detection.

In a method for operating a household microwave appliance, a microwave treatment operation is controlled as a function of a temperature of a microwave generator. The household microwave appliance includes a cooking chamber, a microwave generator for routing microwaves to the cooking chamber, a temperature-determining apparatus for determining a temperature of the microwave generator, a microwave distribution device designed to change a field distribution in the cooking chamber during a microwave treatment operation, and a control device designed to control the microwave treatment operation as a function of the temperature of the microwave generator effected by a change in the field distribution.

A sound sensing module for monitoring the operation of an appliance includes a microphone for monitoring sound generated during operation of the appliance and a controller operably coupled to the microphone. The controller can obtain a sound signal generated during operation of the appliance, analyze the sound signal to identify a sound signature corresponding to an operating event, and implement a responsive action, such as providing a user notification, providing troubleshooting instructions, ordering a replacement part, scheduling a maintenance visit.

A combination microwave and refrigerator system is provided. The microwave oven is connected to a source of power and has a control circuit for controlling the operation of the microwave oven. A first power supply outlet is provided on the microwave oven. A refrigerator is connected to the source of power by connection to the first power supply outlet. The control circuit is configured to disable the cooling operation of the refrigerator, when the microwave oven demands cooking power, and enable the cooling operation of the refrigerator when the microwave oven is not drawing cooking power. A safety sensor is provided in the microwave oven, and is configured to cause cooking power to the microwave oven to be turned off upon the safety sensor sensing a level of smoke.