A microwave heating device includes at least two radiating portions that are adapted to radiate microwaves to the heating chamber and can be operated according to a plurality of operational configurations that differ in frequency and/or in phase shift(s) between the radiated microwaves. Data of energy efficiency, as a function of operational configurations, can be obtained for a product in the heating chamber. For example, energy efficiency data are obtained through a learning procedure. The obtained data can be processed to select one or more operational configurations ranking high in energy efficiency and a heating procedure for the product inside the heating chamber can be executed by operating the at least two radiating portions according to the selected one or more operational configurations.

Method of irradiating a load placed in a cavity by radiating UHF or microwave radiation into the cavity. The method includes setting transmission durations, by setting for each of a plurality of frequencies, a respective transmission duration, repeatedly causing energy to be transmitted into the cavity at the plurality of frequencies according to a duty cycle, wherein the duty cycle defines an allotted transmission time for each of the plurality of frequencies, and switching ON or OFF transmission of the energy at certain frequencies, so that over a plurality of repetitions of the duty cycle the energy is transmitted at each of the plurality of frequencies for the respective transmission duration.

An over-the-range microwave oven including a duct unit configured to direct air from the back of the oven to the front and further includes an integrated duct module. The duct unit includes: a first panel at the bottom, a pair of second panels forming both lateral side surfaces of the duct unit. Water vapor generated from food being cooked flows along an enclosed flow path and thus is unaffected by the exhaust air flow. A humidity sensor is disposed on the first panel and operable to detect water vapor in the cooking unit.

A modular microwave power supply comprises a plurality of microwave power supply modules and a plurality of isolating diodes. To upgrade the output power of the modular microwave power supply, the plurality of microwave power supply modules are connected isolatively in common to a magnetron load by the plurality of isolating diodes, such that power combining of the plurality of microwave power supply modules is achieved, and the efficiency as well as the accumulated-heat dissipating ability of the modular microwave power supply are as good as each of the plurality of microwave power supply modules.

An apparatus for simultaneously heating a plurality of food products, comprising: a containment structure forming a housing chamber; one or more separating elements mounted in the housing chamber to delimit a plurality of separate housing compartments for receiving the food products; radio frequency dielectric heating means with an operating frequency of between 1 MHz and 300 MHz, mounted in the containment structure and comprising at least one first electrode and one second electrode; wherein the housing compartments are aligned along a row, the first electrode and the second electrode delimiting on two opposite sides the row; and wherein inside the housing chamber, between the first electrode and the second electrode , there is also at least one inductor.

A microwave oven is provided herein having a cooking cavity, a dividing shelf for dividing the cooking cavity into at least two sub-cavities, and a door movable between an open and closed position for selectively providing and preventing access to the sub-cavities respectively. The door is provided with a choke frame configured to communicate with the dividing shelf in the closed position so as to attenuate microwave transmission between the sub-cavities.

An electromagnetic energy delivery system includes a set of radio frequency channels. Each channel includes a radio frequency feed, at least one high-power amplifier and a phase-shifting component. Each high-power radio frequency amplifier includes at least one amplifying component configured to output a periodic signal that is amplified in power with respect to an input radio frequency common reference signal. The phase-shifting component is configured to modulate the phase of the output periodic signal with respect to the input radio frequency signal. A controller coupled to the set of radio frequency channels can be configured to cause the output periodic signals from each of the radio frequency channels is to have a time-varying phase difference relative to the common reference signal and a phase difference relative to the other output periodic signals that is constant when averaged over time.

A microwave appliance provides safe heating of packaged food products at an efficiency greater than 90%. A temperature sensor positioned about a product holder is configured to sense a temperature of the package. A product identification scanner identifies a type of food product, a type of packaging, and/or a size of packaging being inserted into the microwave appliance. The product identification may be used to obtain a dielectric constant and/or electrical conductivity of the product. An electric field detector verifies that a suitable product has been inserted into the microwave appliance and is used to estimate a volume of the packaged food product. Accordingly, even partially full packaged food products may be safely re-heated to a desired temperature. As opposed to a time-based operation with traditional microwave appliances, operation of the microwave appliance may be adjusted based on the product identification scanner, temperature sensor, and electric field detector.

A microwave oven is provided herein having a cooking cavity, a dividing shelf for dividing the cooking cavity into at least two sub-cavities, and a door movable between an open and closed position for selectively providing and preventing access to the sub-cavities respectively. The door is provided with a choke frame configured to communicate with the dividing shelf in the closed position so as to attenuate microwave transmission between the sub-cavities.

This disclosure relates to a microwave heating device and a method for operating a microwave heating device. The microwave heating device comprises at least two radiating portions that are adapted to radiate microwaves to the heating chamber and can be operated according to operational configurations that differ in frequency and/or in phase shift(s) between the radiated microwaves. A learning procedure can be executed in relation with at least one product positioned in the heating chamber. The learning procedure can be executed by changing frequency and phase shift(s) to sequentially operate the at least two radiating portions in a plurality of operational configurations, in such a way that, for each frequency, the at least two radiating portions are operated in a number of operational configurations that differ in phase shift(s) from one another. An energy efficiency can be calculated for each of said plurality of operational configurations and the obtained data are saved. A heating procedure may be executed after the learning procedure. In the heating procedure, the at least two radiating portions are operated according to at least one operational configuration that is selected on the basis of the data obtained in the learning procedure.