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 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.

The microwave power is distributed to microwave radiation elements arranged rotationally symmetrically around a reference line on a plane on a top face side of a heating chamber by advancing a feeding phase with a phase difference of 360°/2N clockwise or counterclockwise in turn.

A selective heating device comprises a chamber configured to contain a target to be at least partially heated, an active electromagnetic (EM) element to generate an electromagnetic field in the chamber and a passive EM element in the chamber. The passive EM element is capable of electromagnetically coupling to the active element. The active EM element and passive EM element are controllable to selectively heat a portion of the target.

A microwave oven avoids being upsized. The microwave oven includes a housing including a cooking chamber inside the housing, a component chamber inside the housing, a first opening in a front portion of the housing and communicating with the cooking chamber, and an outlet in a rear portion of the housing and allowing air to be discharged from the component chamber to flow through the outlet. The microwave oven also includes a heat-generating component in the component chamber, a door at a front portion of the housing to cover and uncover the first opening, and a battery mount at a rear portion of the housing to detachably receive a battery pack.

A microwave oven includes a frequency converter, a magnetron, a first conductor, and a second conductor. A power supply end of the fre-quency converter is connected to a power supply end of the magnetron by means of the first conductor, and a ground end of the frequency converter is connected to a ground end of the magnetron by means of the second conductor. The first conductor and a part of the second conductor are arranged in parallel, and the distance between the first conductor and the part of the second conductor is less than a preset distance. In this way, RE of the microwave oven can be reduced, and the microwave oven can thus meet the EMC standards.

Method of processing an object in an energy application zone by radio frequency (RF) radiation emitted by one or more radiating elements configured to emit the RF radiation in response to RF energy applied thereto, wherein the method includes controlling supply of RF energy to the one or more radiating elements via an RF energy supply component, receiving measured response values produced based on RF energy received by the one or more radiating elements from the energy application zone, accessing a stored set of coefficients associated with the RF energy supply component, said set of coefficients being utilized to transform the measured response values and controlling application of RF energy to the one or more radiating elements based on the measured response values and the set of coefficients.

A cooking appliance with microwave heating function is disclosed, which includes a cooker body 10, a first fan 20, a second fan 30, a variable frequency power supply 40 and a magnetron 50. When the cooking appliance with microwave heating function works, on the one hand, the first fan 20 draws in the air outside the cooker body 10 through the side air inlet mesh 1111 and the bottom air inlet mesh 1131, and blows it to the variable frequency power supply 40 for heat dissipation. The large amount of air entering has a good heat dissipation effect on the variable frequency power supply 40. The second fan 30 draws in the air outside the cooker body 10 through the bottom air inlet mesh 1131 or the side air inlet mesh 1111, and blows it to the magnetron 50 for heat dissipation, which achieves a good heat dissipation effect on the magnetron 50. On the other hand, the plane where the air inlet of the first fan 20 is located is arranged obliquely with respect to the bottom cover plate 113, thus compared with a horizontal arrangement, the occupation space of the first fan 20 in a horizontal direction can be reduced to a certain extent, which can increase the volume of the cooking cavity while reducing the heat dissipation effect.

A system includes a radio frequency (RF) signal source configured to supply an RF signal. An electrode is coupled to the RF signal source and a transmission path is between the RF signal source and the electrode. The transmission path is configured to convey the RF signal from the RF signal source to the electrode to cause the electrode to radiate RF electromagnetic energy into a cavity. Power detection circuitry is coupled to the transmission path and configured to repeatedly measure RF power values including at least one of forward RF power values and reflected RF power values along the transmission path. A controller is configured to determine that a load in the cavity is a low-loss load based on a rate of change of the RF power values, and cause the RF signal source to supply the RF signal with the one or more desired signal parameters.

An embodiment of a heating system includes a cavity configured to contain a load, a thermal heating system (e.g., a convection, radiant, and/or gas heating system) in fluid communication with the cavity and configured to heat air, and an RF heating system. The RF heating system includes an RF signal source configured to generate an RF signal, first and second electrodes positioned across the cavity and capacitively coupled, a transmission path electrically coupled between the RF signal source and one or more of the first and second electrodes, and a variable impedance matching network electrically coupled along the transmission path between the RF signal source and the one or more electrodes. At least one of the first and second electrodes receives the RF signal and converts the RF signal into electromagnetic energy that is radiated into the cavity.

In a solid-state heating system, once a load with specific load characteristics has been placed in a heating cavity, a processing unit produces control signals that indicate an excitation signal frequency and one or more phase shifts, which constitute a combination of parameter values. Multiple microwave generation modules produce RF excitation signals characterized by the frequency and the phase shift(s). Multiple microwave energy radiators radiate, into the heating cavity, electromagnetic energy corresponding to RF excitation signals received from the microwave generation modules. Power detection circuitry takes reflected RF power measurements, and the processing unit determines a reflected power indication based on the measurements. The process is repeated for different combinations of the parameter values, and an acceptable combination of parameter values is determined and stored in a memory of the heating system. Acceptable combinations of parameter values similarly may be determined and stored for other loads with different load characteristics.