An electromagnetic cooking device includes an enclosed cavity configured to receive a food load, a plurality of high power amplifiers and RF feeds for introducing electromagnetic radiation into the cavity, and a controller for controlling the frequency, phase and amplitude of the electromagnetic radiation fed into the cavity by the RF feeds. The controller is configured to identify resonant modes, develop and implement a heating strategy based on the resonant modes, utilize an asynchronous manager to automatically detect when a variable has changed to a degree that requires an updated identification of resonant modes and an updated heating strategy, and if the asynchronous manager determines that updates are needed, repeat the steps above to determine a new heating strategy, otherwise continue with the current heating strategy.

A multi-mode microwave heating device includes a heating chamber, a plurality of microwave transmitters, a plurality of longitudinal-polarized rectangular waveguides, a plurality of transverse-polarized rectangular waveguides, and a plurality of half-wave-rectified power supplies. The heating chamber has a holder for holding a to-be-heated object. The holder is connected to a rotating and an elevating mechanism. The microwave transmitters are connected to the heating chamber through the longitudinal-polarized rectangular waveguides as well as connected to the transverse-polarized rectangular waveguides for transmitting microwaves into the heating chamber and to excite multiple cavity modes of the heating chamber, so as to achieve uniform microwave heating. An industrial three-phase alternating current (AC) power source offers multi-phased electricity to the half-wave-rectified power supplies, by which the microwave transmitters are powered, such that the multiple modes are decoupled and uniform microwave heating are achieved.

Method and systems for heating an item in a chamber comprising applying a first electromagnetic wave to an array of variable reflectance elements and corresponding array of variable impedance devices is disclosed. The corresponding array includes first and second variable impedance devices. The method also comprises reflecting, when the first device has a first impedance value, the first wave from the array to the item. The reflecting places a local maximum of energy at a first location on the item. The method also comprises altering an impedance of the first device. The method also comprises applying a second electromagnetic wave, and reflecting the second wave from the array to the item. The reflecting places the local maximum at a second location on the item. Altering the impedance of the first variable impedance device alters a reflectance of a first variable reflectance element in the array of variable reflectance elements.

Method and systems for heating an item in a chamber comprising applying a first electromagnetic wave to an array of variable reflectance elements and corresponding array of variable impedance devices is disclosed. The corresponding array includes first and second variable impedance devices. The method also comprises reflecting, when the first device has a first impedance value, the first wave from the array to the item. The reflecting places a local maximum of energy at a first location on the item. The method also comprises altering an impedance of the first device. The method also comprises applying a second electromagnetic wave, and reflecting the second wave from the array to the item. The reflecting places the local maximum at a second location on the item. Altering the impedance of the first variable impedance device alters a reflectance of a first variable reflectance element in the array of variable reflectance elements.

Processes and systems that enhance the heating of packaged foodstuffs and other items in various microwave heating systems are described herein. The foodstuffs may be contained in a package including one or more energy control elements that interact with microwave energy in order to alter the effect that microwave energy has on the foodstuff. These energy control elements can enhance or inhibit microwave energy and a single package may include one or more energy control elements. In some cases, the energy control element may respond differently to different types of microwave energy. As a result, some packages described herein may exhibit different absorption or reflectance characteristics when exposed to microwave energy while being pasteurized or sterilized in a larger-scale microwave heating system than when the package is reheated in an at-home microwave oven prior to consumption or use.

An electronic oven with a set of variable reflectance elements for controlling a distribution of heat in the electronic oven and associated methods are disclosed herein. The electronic oven includes a chamber, an energy source coupled to an injection port in the chamber, and a set of variable reflectance elements located in the chamber. In some of the disclosed approaches the variable reflectance elements are nonradiative. A control system of the electronic oven can be configured to alter the states of the variable reflectance elements to thereby alter and control the distribution of energy within the chamber.

A selective heating device comprises a chamber configured to contain a target to be at least partially heated, an active electromagnetic (EM) element to generate an electromagnetic field in the chamber and a passive EM element in the chamber. The passive EM element is capable of electromagnetically coupling to the active element. The active EM element and passive EM element are controllable to selectively heat a portion of the target.

Disclosed is a microwave irradiating and heating device including: a reaction furnace (1) for containing a sample material (50) to be irradiated with microwave and to be heated; a polarization grid (2) provided for the reaction furnace (1); a microwave irradiating source (3) for emitting a linearly polarized microwave, the microwave irradiating source (3) being disposed outside the reaction furnace (1); and a reflector (4) for reflecting the microwave emitted from the microwave irradiating source (3) toward the reaction furnace (1) through the polarization grid (2), the reflector (4) being disposed above the reaction furnace (1), wherein the microwave irradiating source (3) is arranged in such a way that the polarization direction of the reflected microwave which is made incident upon the polarization grid (2) is perpendicular to an orientation of the polarization grid (2).

Disclosed is a microwave irradiating and heating device including: a reaction furnace (1) for containing a sample material (50) to be irradiated with microwave and to be heated; a polarization grid (2) provided for the reaction furnace (1); a microwave irradiating source (3) for emitting a linearly polarized microwave, the microwave irradiating source (3) being disposed outside the reaction furnace (1); and a reflector (4) for reflecting the microwave emitted from the microwave irradiating source (3) toward the reaction furnace (1) through the polarization grid (2), the reflector (4) being disposed above the reaction furnace (1), wherein the microwave irradiating source (3) is arranged in such a way that the polarization direction of the reflected microwave which is made incident upon the polarization grid (2) is perpendicular to an orientation of the polarization grid (2).

A multi-mode microwave heating device includes a heating chamber, a plurality of microwave transmitters, a plurality of longitudinal-polarized rectangular waveguides, a plurality of transverse-polarized rectangular waveguides, and a plurality of half-wave-rectified power supplies. The heating chamber has a holder for holding a to-be-heated object. The holder is connected to a rotating and an elevating mechanism. The microwave transmitters are connected to the heating chamber through the longitudinal-polarized rectangular waveguides as well as connected to the transverse-polarized rectangular waveguides for transmitting microwaves into the heating chamber and to excite multiple cavity modes of the heating chamber, so as to achieve uniform microwave heating. An industrial three-phase alternating current (AC) power source offers multi-phased electricity to the half-wave-rectified power supplies, by which the microwave transmitters are powered, such that the multiple modes are decoupled and uniform microwave heating are achieved.