Disclosed are methods and apparatuses for heating an object in a cavity by feeding the cavity with RF signals. One of the disclosed methods includes simultaneously feeding the cavity with at least two RF signals. Of the at least two RF signals, a first RF signal is fed to the cavity via a first antenna and a second RF signal is fed to the cavity via a second antenna. The first and second RF signals have a common frequency and differ in phase by a first phase difference. The method also includes measuring the first phase difference and adjusting the feeding based on measurements of reflected RF signals reflected from the cavity. Conducting the measurements of the reflected RF signals may also be part of the disclosed method. A disclosed apparatus includes the structure required for carrying out the above method.

An oven may include a cooking chamber configured to receive a food product, a radio frequency (RF) heating system configured to provide RF energy into the cooking chamber using solid state electronic components to heat the food product, and a context awareness engine. The context awareness engine may include processing circuitry configured to receive RF signature data (including measurements of at least forward power and reflected power) associated with provision of RF energy into the cooking chamber, and to correlate an RF signature with a phenomenon observed with respect to the food product to define a signature profile for the phenomenon observed.

The present invention relates to a medical preparation container which includes a microwave power sensor assembly. The microwave powered sensor assembly includes a sensor configured to measure a physical property or chemical property of a medical preparation during its heating in a microwave oven. The microwave powered sensor assembly is configured for harvesting energy from a microwave radiation emitted by the microwave oven and energize the sensor by the harvested microwave energy.

A microwave oven is described herein. In some instances, such a microwave oven may include a housing; a rotating turntable assembly disposed in a cooking cavity of the housing; a probe powered by the turntable assembly, where the probe is configured to measure an environmental condition during a cooking cycle and where the probe is configured to transmit a signal regarding the environmental condition; and a controller disposed in the housing and configured to receive the signal regarding the environmental condition from the probe. A method of operating a microwave oven for sous vide cooking is also disclosed.

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.

In an embodiment, an apparatus includes a radio frequency (RF) generator that is to generate a RF signal, first and second electrodes, and an impedance match module in series between the RF generator and the first electrode. The RF generator detects reflected power from the RF signal applied to a load electrically coupled between the first and second electrodes to change a temperature of the load, the RF signal to be applied to the load until the reflected power reaches a particular value.

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 datalogger with a temperature sensor for measuring the temperature of one or more articles during a radio frequency (RF) heating process. The datalogger may be wireless and may store temperature measurements in an internal memory and/or may wirelessly transmit temperature data in real-time. The datalogger may be specifically designed and oriented to maximize temperature measurement accuracy and minimize interference with the RF heating process.

In an embodiment, an apparatus includes a radio frequency (RF) generator that is to generate a RF signal, first and second electrodes, and an impedance match module in series between the RF generator and the first electrode. The RF generator detects reflected power from the RF signal applied to a load electrically coupled between the first and second electrodes to change a temperature of the load, the RF signal to be applied to the load until the reflected power reaches a particular value.

A defrosting system includes an RF signal source, an electrode proximate to a cavity within which a load to be defrosted is positioned, and a transmission path between the RF signal source and the electrode. The system also includes power detection circuitry coupled to the transmission path and configured repeatedly to take forward and reflected RF power measurements along the transmission path. A system controller repeatedly determines, based on the forward and reflected RF power measurements, a calculated rate of change, and repeatedly compares the calculated rate of change to a threshold rate of change. When the calculated rate of change compares favorably with the threshold rate of change, the RF signal source continues to provide the RF signal to the electrode until a determination is made that the defrosting operation is completed, at which time the RF signal source ceases to provide the RF signal to the electrode.