Aspects of the present invention relate to systems and methods for customizing microwave energy distribution within a chamber to accommodate various load characteristics. Additional aspects of the present invention relate to customized configurations of ports, deflectors, waveguides, conducting rods, and slots to shape and distribute energy.

Aspects of the present invention relate to systems and methods for customizing microwave energy distribution within a chamber to accommodate various load characteristics. Additional aspects of the present invention relate to customized configurations of ports, deflectors, waveguides, conducting rods, and slots to shape and distribute energy.

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.

The microwave heating apparatus (100) comprises a cavity (101) arranged to receive a load (102A, 102B), at least two patch antennas (103A, 103B) coupled to the at least one microwave generator (104), and a control unit (105). Each of the at least two patch antennas (103A, 103B) is configured to radiate microwaves into a predefined direct heating zone (108A, 108B) within the cavity proximate the respective patch antenna (103A, 103B). The control unit (105) is configured to select energy levels for each of the at least two patch antennas (103A, 103B) as if the load (102A, 102B) were static and as if there not interference between the at least two patch antennas (103A, 103B).

An electromagnetic energy delivery system includes a set of radio frequency channels. Each channel includes a radio frequency feed, at least one high-power amplifier and a phase-shifting component. Each high-power radio frequency amplifier includes at least one amplifying component configured to output a periodic signal that is amplified in power with respect to an input radio frequency common reference signal. The phase-shifting component is configured to modulate the phase of the output periodic signal with respect to the input radio frequency signal. A controller coupled to the set of radio frequency channels can be configured to cause the output periodic signals from each of the radio frequency channels is to have a time-varying phase difference relative to the common reference signal and a phase difference relative to the other output periodic signals that is constant when averaged over time.

A device for producing exfoliated graphite from graphite flakes, intercalated graphite, or expanded graphite by means of microwave heating using single mode microwave cavities, a method of producing such materials and products from such methods.

The invention relates to a method for operating a microwave device (1), the microwave device (1) comprising a cavity (2) and multiple microwave channels (CH1-CH4) for providing microwaves within said cavity (2), the method comprising the steps of: operating one or more microwave channels (CH1-CH4) at one or more first power levels and with varying phases in a data acquisition mode; gathering information regarding channel reverse power (RP) at the one or more microwave channels (CH1-CH4) during said data acquisition mode; establishing a mathematical model for each microwave chan-nel (CH1-CH4) based on said gathered information, said mathematical model providing information regarding channel reverse power (RP) for the respective microwave channel (CH1-CH4); determining operating parameters based on the established mathematical models; and, operating the microwave channels (CH1-CH4) of the microwave device (1) at one or more second power levels based on the determined operation parameters, the power of the second power levels being higher than the power of the first power levels.

An electromagnetic cooking device and method of controlling the same is provided herein. The cooking device has a cavity in which a liquid is placed and a plurality of RF feeds configured to introduce electromagnetic radiation into the cavity for heating the liquid. A controller is provided and is configured to: analyze forward and backward power at the plurality of RF feeds to calculate efficiency; determine and monitor a coefficient of variation of the efficiency; detect a specified temperature of the liquid based on changes in the coefficient of variation; and adjust a power level of the electromagnetic radiation in response to detection of the specified temperature.

An electromagnetic cooking device and method of controlling the same is provided herein. The cooking device has a cavity in which a liquid is placed and a plurality of RF feeds configured to introduce electromagnetic radiation into the cavity for heating the liquid. A controller is provided and is configured to: analyze forward and backward power at the plurality of RF feeds to calculate efficiency; determine and monitor a coefficient of variation of the efficiency; detect a specified temperature of the liquid based on changes in the coefficient of variation; and adjust a power level of the electromagnetic radiation in response to detection of the specified temperature.

A radio frequency antenna for radiating electromagnetic energy into a reservoir filled with a target material, the antenna being operatively connected to a feed transmission line. The antenna includes a waveguide, at least one slot formed in the outer waveguide layer, and a sleeve portion enclosing at least a portion of the waveguide. The sleeve portion comprises at least first and second dielectric layers where the permittivity of the second dielectric layer is higher than the permittivity of the first dielectric layer and the first dielectric layer is positioned in closer proximity to the waveguide than the second dielectric layer. When the antenna is inserted into the reservoir, the input impedance of the antenna remains matched to the feed transmission line for a wide range of target materials.