A household microwave appliance operates with multiple parameter configurations to treat food to be cooked in a locally differing manner. The microwave appliance determines in an initial scan with a thermal imaging sensor directed into the cooking chamber a temperature distributions on a surface of the food to be cooked. Change patterns are obtained from differences between different temperature distributions. An evaluation value is calculated for a best heating pattern that brings the current temperature distribution closest to a target temperature distribution determined based on a normalized target state and a current temperature distribution, whereafter microwave power is applied to the food to be cooked with the parameter configuration associated with the best heating pattern.

There are provided heating chamber, and reflection angle control device provided on upper wall configuring at least part of walls of heating chamber and configured to control a reflection angle of a microwave to control standing wave distribution in heating chamber. Reflection angle control device controls the reflection angle of the microwave when the microwave radiated from microwave radiation device is not directly absorbed into heating target but is reflected by the wall. Standing wave distribution in heating chamber can thus be controlled to be different from ordinary distribution for improvement in local heating performance.

There are provided heating chamber, and reflection angle control device provided on upper wall configuring at least part of walls of heating chamber and configured to control a reflection angle of a microwave to control standing wave distribution in heating chamber. Reflection angle control device controls the reflection angle of the microwave when the microwave radiated from microwave radiation device is not directly absorbed into heating target but is reflected by the wall. Standing wave distribution in heating chamber can thus be controlled to be different from ordinary distribution for improvement in local heating performance.

Method and systems for heating an item in a chamber where a first electromagnetic wave is applied to an array of variable reflectance elements and a corresponding array of variable impedance devices are disclosed. The corresponding array includes first and second variable impedance devices. The first wave is reflected from the array to the item when the first device has a first impedance value. The reflecting places a local maximum of energy at a first location on the item. An impedance of the first device is altered. A second electromagnetic wave is applied and reflected. The reflecting places the local maximum at a second location on the item. Altering the impedance of the first variable impedance device alters a reflectance of a first variable reflectance element in the array of variable reflectance elements.

A microwave oven comprising a cavity in which a material can be placed for heating and a magnetron for generating a microwave. The microwave oven further comprises an electromagnetic element adapted to interact with microwaves into the cavity and a control unit that provides a control signal to the electromagnetic element for modifying an impedance of the electromagnetic element during time of heating.

A microwave oven comprising a cavity in which a material can be placed for heating and a magnetron for generating a microwave. The microwave oven further comprises an electromagnetic element adapted to interact with microwaves into the cavity and a control unit that provides a control signal to the electromagnetic element for modifying an impedance of the electromagnetic element during time of heating.

An electromagnetic cooking device and cooking method to perform zone cooking is disclosed. The method includes scanning a resonant cavity in which a food load has been placed with RF feeds that are coupled to respective high power amplifiers; identifying resonant frequencies and corresponding phases of the RF feeds; storing a resonance map; classifying symmetries in the resonant map; determining paths defining stirring routes between poles of different symmetries; determining midpoints in the paths with a maximum unbalance between reflected powers of the respective high power amplifiers; classifying the unbalance in terms of power steered to the left and right sides of the food load; synthesizing a heating strategy for zone cooking using the classified unbalance; and implementing the heating strategy by causing the plurality of high power amplifiers and RF feeds to introduce electromagnetic radiation at specific selected frequencies and phases into the cavity based on the heating strategy.

A microwave oven has a magnetron (11) which generates microwaves to heat a heating object, and a control unit (100) which controls the magnetron (11). During heating operation in which the heating object is heated with microwaves generated from the magnetron (11), the control unit (100) controls the magnetron (11) so as to suppress abnormal operations of the magnetron (11) in response to a status of power supply supplied from outside.

Embodiments include microwave cooking systems and methods of their operation, which are configured to heat food loads. Using a phased array, frequency and phase conditions and corresponding return losses are mapped in a cavity of the microwave cooking system. Using one or more thermal cameras, positions of E field maximums also are mapped in the cavity. The frequency and phase conditions are time division multiplexed so that heat maximums sum over a cooking cycle to provide a heating profile in a zone of interest.

The catalyst heating device includes: an irradiation unit; and a control unit. The irradiation unit includes an antenna and is configured to radiate a microwave through the antenna to a catalyst device which has microwave absorbability and is configured to purify gas, to heat the catalyst device. The control unit has a function of allowing the irradiation unit to make irradiation with the microwave under an irradiation condition including at least any of a frequency of the microwave and a position of the antenna, and has a function of changing the irradiation condition.