A radio frequency (RF) heating and defrosting apparatus may include an electrode which, when supplied with RF signal energy, may responsively radiate electromagnetic energy into a cavity of the RF heating and defrosting apparatus. This radiated electromagnetic energy may cause a thermal increase of a load in the cavity. A capacitor may be formed from a portion of the electrode and a conductive plate disposed adjacent to the electrode. The conductive plate may be coupled to a ground reference structure. Dielectric material(s) having a low dielectric constant may be disposed directly between the electrode and the conductive plate.

A method for identifying a cooking level of a food load in an electromagnetic cooking device is disclosed. The method comprises 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 comprises 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 comprises 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.

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.

A method for controlling a power of an electromagnetic cooking device is disclosed. The method comprises 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 comprises 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.

A system and method for defrosting or heating are presented. A radio frequency (RF) signal source provides, through a transmission path, an RF signal to an electrode that is proximate to a cavity of a defrosting system. A rate of change of a ratio of a reflected RF power measurement and a forward RF power measurement along the transmission path is determined to have transitioned from a relatively high value to a relatively low value. At a point in time when the determination is made, the RF signal is provided to the electrode for an additional time duration beyond the point in time, and provision of the RF signal to the electrode is ceased when the additional time duration has expired.

A cooking appliance includes a cooking chamber for cooking a product to be cooked. An air-guiding plate is arranged in the cooking chamber and coupled by a coupling device to a transmitter/receiver unit which transmits and/or receives a high frequency signal. The air-guiding plate is configured as a planar antenna for transmitting the high frequency signal between the coupling device and a sensor that can be arranged in the cooking chamber.

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.

Approaches relating to electronic ovens are disclosed. One approach involves an electronic oven with a heating chamber and an energy source that is coupled to an injection port in the heating chamber for introducing an application of energy into the chamber. The electronic oven also comprises a control system to adjust a distribution of the application of energy in the heating chamber, and a set of radio frequency (RF) responsive sensors in the heating chamber. Each RF responsive sensor in the set of RF responsive sensors directly responds to the application of energy in the heating chamber. The control system includes a machine learning system. The control system uses data from each RF responsive sensor in the set of RF responsive sensors to create a set of training data. The control system uses the set of training data to train the machine learning system.

A system includes a core temperature probe and a microwave cooking device. The core temperature probe includes a temperature sensor to determine a temperature information, a coaxial line including a lambda/4 line resonance element adjusted to a microwave frequency, and a signal transmission antenna connected to the temperature sensor via the coaxial line and adapted to emit the temperature information at a signal transmission frequency that differs from the microwave frequency. The system is hereby constructed to transmit a signal at the signal transmission frequency wirelessly between the signal transmission antenna of the core temperature probe and a signal transmission antenna of the microwave cooking appliance.

An apparatus for relaying microwave field intensity in a microwave cavity. In some embodiments, the apparatus comprises a microwave transparent substrate with at least one Radio Frequency (RF) detector that is capable of detecting a microwave field and generating a signal associated with a field intensity of the detected microwave field and a transmitter that receives the signal associated with the detected microwave field from the RF detector and transmits or stores information about the detected microwave field intensity. In some embodiments, the apparatus relays the microwave intensity via a wired, wireless, or optical transmitter located in proximity of the RF detector.