The invention relates to a method and apparatus for determining a size information of food ingredients. The method comprises a step of applying (110) to the food ingredients an electrical field having a given radio frequency, the electrical field being generated by a source positioned in close proximity to the food ingredients, a first step of measuring (120) a ratio between the energy of the electrical field reflected from the food ingredients, and the energy of the electrical field generated by said source and applied to the food ingredients. The method also comprises a first step of determining (130), based on said ratio, an average thickness of the food ingredients along the direction of the electrical field applied to the food ingredients. The method also comprises a second step of measuring (140), for a plurality of distances between the source of the electrical field and the food ingredients, the ratio (R2) between the energy of the electrical field reflected from the food ingredients, and the energy of the electrical field applied to the food ingredients. The method further comprises a step of identifying (150) a relatively sudden change in the amplitude of the ratios measured by said second step of measuring (140) and a step of deriving (160) the corresponding distance between the source of the electrical field and the food ingredients for which said relatively sudden change occurred. The method also comprises a second step of determining (170), based on said corresponding distance and the divergent angle of the electrical field irradiating at said corresponding distance, an average diameter of the food ingredients in a plane perpendicular to the direction of the electrical field applied to the food ingredients. This invention results in a more convenient, robust and accurate way to determine the average thickness of the food ingredients.

Systems and methods include a cooking appliance comprising a heating element disposed within a cooking chamber and operable to selectively emit waves at any of a plurality of powers and/or peak wavelengths, a camera operable to capture an image of the cooking chamber, and a computing device operable to supply power to the heating element to vary the power and/or peak wavelength of the emitted waves and generate heat within the cooking chamber, and instruct the camera to capture the image when the heating element is emitting at a stabilized power and/or peak wavelength. The computing device is operable to generate an adjusted captured image by adjusting the captured image with respect to the stabilized power and/or peak wavelength. The computing device comprises feedback components operable to receive the adjusted captured image, extract features, and analyze the one or more features to determine an event, property, measurement and/or status.

The invention relates to a method (100) and apparatus for controlling the heating of food ingredients. The method comprises the step of measuring (110) the spectrum of energy absorption of the food ingredients in a given range of radio frequencies. The method also comprises the step of identifying (120), in said given range of radio frequencies, the radio frequency for which the food ingredients have the maximum energy absorption. The method also comprises the step of applying (130) an electrical field to the food ingredients, said electrical field having a radio frequency corresponding to said radio frequency for which the food ingredients have the maximum energy absorption. The step of measuring (110) comprises, for a plurality of selected radio frequencies in said given range of radio frequencies, the steps of: applying an electrical field on the food ingredients having a radio frequency corresponding to a given selected radio frequency in said plurality of selected radio frequencies; and, measuring the ratio between the energy of the radio frequency electrical field reflected or absorbed from the food ingredients, and the energy of the radio frequency electrical field applied to the food ingredients. The plurality of selected radio frequencies are selected from said given range of radio frequencies by the steps of: for each of said given range of radio frequencies, obtaining a penetration depth of an electrical field having a radio frequency corresponding to the given radio frequency into the food ingredients, and including the given radio frequency into the plurality of selected radio frequencies if the penetration depth of the electrical field having radio frequency corresponding to the given radio frequency is equal to or larger than the thickness of the food ingredients in the direction of the electrical field applied to the food ingredients. This invention allows reducing the heating time of food ingredients.

Several embodiments include a cooking instrument. The cooking instrument can include a heating system. The heating system can include one or more heating elements capable of emitting wireless energy into the cooking chamber. The cooking instrument can also include a control system. The control system can executing a heating sequence to drive the heating system, detect, based on an output signal of a sensor, a trigger event, and configure the heating system in response to detecting the trigger event.

A method for heating or cooking a frozen food product with a susceptor in a solid state microwave oven includes placing the frozen food product with a susceptor into a microwave oven, heating the food product at a first heating step at a low absorption frequency, and heating the food product at a second heating step at a high absorption frequency.

An embodiment of a heating system includes a cavity configured to contain a load, a thermal heating system, and an RF heating system. The RF heating system includes a system controller, an RF signal source, one or more electrodes that receive an RF signal from the RF signal source and radiate resultant electromagnetic energy into the cavity, and a variable impedance matching network coupled between the RF signal source and the one or more electrodes. The system controller may monitor an impedance state of the variable impedance matching network to identify the occurrence of a change point. The system controller may estimate the mass of the load and a time and/or energy requirement for cooking the load based on the change point. The system controller may take action by turning off the RF heating system and/or thermal heating system when the time or energy requirement has been met.

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.

A method for controlling a power of an electromagnetic cooking device is shown. The method includes controlling a power supply to deliver a power level to the amplifier and monitoring at least one RF feed delivered to an enclosed cavity. The method further includes identifying an output power based on the RF feed and comparing the output power to a maximum power. A power difference of the output power compared to a target power is determined, and the power difference is compared to a plurality of difference thresholds. Based on the comparison, the power level is adjusted by a plurality of power adjustment magnitudes.

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.

Methods and apparatuses for drying, especially cannabis, are provided. One of the provided methods includes: heating the cannabis in a cavity of a variable frequency microwave oven using at least two different frequencies; measuring temperature of at least 1 cm square of the cannabis at different times during the heating; and controlling the heating based on the temperature measured so that the cannabis is kept for at least 20 minutes at temperatures above 30° C. and below 100° C.