The present disclosure provides a radio frequency detecting device, a detecting method, and a microwave oven, and the radio frequency detecting device comprises: a signal transmitting device configured to generate and transmit multiple forward frequency detecting signals of different frequencies; a signal receiver configured to receive multiple reverse frequency detecting signals reflected by the load; a first detection device configured to detect each first parameter corresponding to each of the forward frequency detecting signals; a second detection device configured to detect each second parameter of each of the reverse frequency detecting signals; and a microcontroller configured to determine a state parameter of the load based on the multiple frequencies and the first parameter and the second parameter corresponding to each of the frequencies.

The invention relates to a method for determining properties of the electrical current provided to an induction heating element (2) of an induction cooking appliance (1), the induction cooking appliance (1) comprising a heating power energy unit (3) including a heating power generator (4) with at least one switching element (5) adapted to provide pulsed electric power to said induction heating element (2), the induction cooking appliance (1) further comprising an oscillating circuit (6) comprising at least one resonance capacitor (6.1, 6.2), said induction heating element (2) being electrically coupled with said heating power generator (4) and said oscillating circuit (6), the induction cooking appliance (1) further comprising a control entity (8), wherein an input of a measurement circuit (9) is coupled with a node of the heating power energy unit (3).

Control electronics may control power amplifier electronics associated with application of RF energy generated using solid state electronic components. The power amplifier electronics may be configured to control application of RF energy in an oven according to a cooking recipe at least in part based on a learning procedure that generates a power cycling between high and low powers when the learning procedure is executed. The control electronics may include processing circuitry configured to employ a thermal stress mitigation technique to control thermal stresses on the power amplifier electronics associated with the power cycling.

A microwave treatment device comprises: a heating chamber that accommodates a heating target, a microwave generator that generates a microwave; a feeding unit that supplies the microwave to the heating chamber; a reflected microwave power detector that detects a reflected microwave power returned to the microwave generator; a controller that controls the microwave generator; and a storage unit. The storage unit stores a level of the reflected microwave power detected by the reflected microwave power detector together with a frequency of the microwave supplied to the heating chamber and an elapsed time after a start of heating the heating target. The controller causes the microwave generator to execute a frequency sweep over a specified frequency band and determines that the heating target is in a boiling state based on a temporal change in a value that is obtained based on the reflected microwave power at each frequency.

A microwave heating method and a microwave heating device are provided. The microwave heating method includes the following steps. An electric field mode distribution at each frequency point generated by the microwave outputted from each input port of the heating chamber is calculated. A frequency, phase, and power of the microwave outputted from each input port are changed to generate a corresponding electric field mode distribution. The electric field mode distributions generated by the input ports are synthesized into a synthesized electric field mode distribution. A power density distribution is calculated. It is calculated whether spatial uniformity of the power density distribution is greater than a target value. The controller heats the object to be heated through the microwave corresponding to the frequency, phase, and power emitted by the microwave transmitter corresponding to each input port.

A method of determining heating strategies for a cooking appliance (10) includes obtaining geometry dimensions, power values, and frequency values of the cooking appliance (10), selecting a food item (14) and obtaining a food geometry, permittivity value, and initial temperature of the selected food item (14). A heating pattern (28) for heating the selected food item (14) is estimated based on the food geometry, permittivity value, and initial temperature of the selected food item (14) and data indicative of the estimated heating pattern (28) is inputted to an operating control system (21) to achieve the estimated heating strategy.

A method for identifying a cooking level of a food load in an electromagnetic cooking device is disclosed. The method includes controlling a frequency and a phase of a first RF signal and a second RF signal and amplifying the first RF signal and the second RF signal thereby generating a first RF feed and a second RF feed. The method further includes emitting the first RF feed and the second RF feed into an enclosed cavity to heat a food load and measuring at least one reflection signal. The method further includes calculating a Q-factor for the enclosed cavity based on the reflection signal, monitoring the Q-factor, and identifying a change in the Q-factor exceeding a predetermined change threshold. In response to identifying the change exceeding the predetermined change threshold, a cooking level for the food load is identified.

In a method for detecting a standstill of a rotatable microwave distribution apparatus of a household microwave appliance, while microwaves are being supplied into a cooking compartment of the household microwave appliance, a microwave leakage radiation for angle-dependent recurring fluctuations is monitored and an action in the absence of such fluctuations being detected.

A method for analyzing a frequency response of a cooking device is disclosed. The method comprises controlling a plurality of RF signals within an operating range of the cooking device at plurality of phase shifts between a first RF signal and a second RF signal. A plurality of efficiencies of at least one reflection signal in the resonant cavity are measured in response to a plurality of RF feeds generated from the RF signals for the plurality of phase shifts. The frequency response of the resonant cavity is modeled with a numeric model and a plurality of interpolation parameters for the numeric model are calculated based on the plurality of measured efficiencies of the RF feeds. The frequency response of the cavity is estimated for the operating range of the cooking device based on the numeric model with the plurality of interpolation parameters.

The present invention discloses a method of controlling transmitting frequencies of microwave source, which includes the following steps of: a) collecting reflection frequencies of a load according to a pre-set sampling rate; b) calculating a change rate of the reflection frequencies collected in the step a; c) setting a reflection frequency threshold and a change rate threshold; d) comparing the reflection frequencies and the change rate with the reflection frequency threshold and the change rate threshold respectively; wherein if the reflection frequencies or the change rate is less than the threshold goes to step e or returns to the step a; e) sending control signals to the microwave source and tuning the transmitting frequencies; and f) returning to step a. The present invention also discloses a microwave transmission system thereof. The present invention can be applied in controlling microwave source consists of single magnetron tube or multiple magnetron tubes.