Whirlpool Corporation

Olle Niklasson

Hakan Carlsson

Fredrik Hallgren

Ulf Nordh

A microwave heating apparatus and methods of controlling cooling of a microwave heating apparatus are provided. The microwave heating apparatus typically includes a microwave source for generating microwaves, a cooling unit for cooling the microwave source and a control unit. According to one embodiment, the control unit is configured to receive operational data from a measuring device indicative of the measured power of microwaves transmitted from the magnetron and receive operational data from the measuring device indicative of the measured anode current of the magnetron. A calculating device calculates an efficiency of the magnetron as a function of the measured power of the transmitted microwaves and the measured anode current, to define a determined efficiency. The control unit controls the cooling unit and cools the magnetron based on the determined efficiency.

Methods of controlling cooling in a microwave heating apparatus and apparatus thereof

A method and apparatus for operating a microwave heating apparatus includes a microwave source adapted to feed microwaves to a cavity via a transmission line, including measuring a power of microwaves transmitted from the microwave source to the cavity, receiving operational data indicative of the power supplied to the microwave source, and adjusting at least one of an impedance of the transmission line or the impedance matching between the microwave source and the transmission line based on the measured power of the transmitted microwaves and the received operational data.

Control of microwave source efficiency in a microwave heating apparatus

A microwave heating apparatus and a method of operating a microwave heating apparatus are provided. The microwave heating apparatus comprises a load receiving cavity, at least one microwave source, a plurality of feeding ports connected to the microwave source and the cavity for feeding microwaves to the cavity, a measuring unit and a control unit. The measuring unit measures, for at least one frequency or within a frequency range, the power of microwaves reflected back to the microwave source for at least part of the plurality of feeding ports. The control unit selects at least one of the feeding ports based on the measured powers of the reflected microwaves in order to feed microwaves to the cavity via the at least one selected feeding port during operation of the microwave heating apparatus at the at least one frequency or within the frequency range.

Microwave heating apparatus and method of operating such a microwave heating apparatus

A microwave heating apparatus and a method for heating/browning a piece of food by means of microwaves are provided. The microwave heating apparatus comprises a cavity arranged to receive, in a substantially horizontal browning region, a piece of food to be browned. The microwave heating apparatus further comprises a microwave source for generating microwaves and a rotatable antenna arranged at the cavity bottom for supplying the generated microwaves. The antenna is configured to produce at least one radiating lobe pointing towards the browning region such that the intersection between the radiating lobe and the browning region forms a hot spot, thereby forming a ring-shaped heating pattern in the browning region under rotation of the antenna. The present invention is advantageous in that a microwave heating apparatus with an improved crisp function is provided.

Microwave heating apparatus with rotatable antenna and method thereof

A microwave heating apparatus and methods of controlling cooling of a microwave heating apparatus are provided. The microwave heating apparatus typically includes a microwave source for generating microwaves, a cooling unit for cooling the microwave source and a control unit. According to one embodiment, the control unit is configured to determine the efficiency of the microwave source and then to control the cooling based on the determined efficiency. The methods and the microwave heating apparatuses of the present invention are advantageous with respect to energy consumption.

A microwave heating apparatus for heating a load by means of microwaves is provided. The microwave heating apparatus comprises a cavity arranged to receive a piece of food to be heated, a first microwave supply system configured to supply microwaves at the cavity bottom for energizing a browning function in the cavity, a second microwave supply system configured to supply microwaves into the cavity for exciting cavity modes and a control unit configured to control the first and second microwave supply systems based on a food category and/or a cooking program. The first supply system comprises at least one microwave source and at least one antenna arranged in a lower part of the cavity and the second microwave supply system comprises at least one microwave source and at least one feeding port arranged in an upper part of the cavity. The present invention is advantageous in that a microwave heating apparatus with an improved crisp function is provided.

Versatile microwave heating apparatus

A microwave heating apparatus for heating a load by means of microwaves is provided. The microwave heating apparatus has a cavity arranged to receive a piece of food to be heated, a first microwave supply system configured to supply microwaves at the cavity bottom for energizing a browning function in the cavity, a second microwave supply system configured to supply microwaves into the cavity for exciting cavity modes and a control unit configured to control the first and second microwave supply systems based on a food category and/or a cooking program. The first supply system has at least one microwave source and at least one antenna arranged in a lower part of the cavity and the second microwave supply system has at least one microwave source and at least one feeding port arranged in an upper part of the cavity. The present invention is advantageous in that a microwave heating apparatus with an improved crisp function is provided.

A microwave heating apparatus and a method of heating a load using microwaves is disclosed. The microwave heating apparatus comprises a cavity arranged to receive a load, a microwave generator, a transmission line arranged to transmit the generated microwaves to the cavity and a sensing device arranged to measure electromagnetic field strengths at different positions along the transmission line. The positions are selected such that the measured field strengths provide information about the phase of a reflection coefficient being representative of the ratio between the amount of microwaves reflected back towards the microwave generator and the amount of microwaves transmitted in the transmission line from the microwave generator. The microwave heating apparatus further comprises a control unit configured to control feeding of the microwaves to the cavity based on the measured field strengths.

Microwave heating apparatus

A method of operating a microwave oven and a microwave oven are disclosed. The microwave oven comprises a magnetron for providing microwave power to heat a load placed in the microwave oven, and a solid-state microwave generator for providing microwave power to sense presence and/or determine nature of the load in the microwave oven.

Microwave oven and related method

A microwave heating device comprises a cavity arranged to receive a load to be heated and a feeding structure for feeding microwaves in the cavity. The feeding structure comprises a transmission line for transmitting microwave energy generated by a microwave source and a resonator arranged at the junction between the transmission line and the cavity for operating as a feeding port of the cavity. The dielectric constant of the material constituting the interior of the resonator and the dimensions of the resonator are selected such that a resonance condition is established in the resonator for the microwaves generated by the source and impedance matching is established between the transmission line, the resonator and the cavity. In addition, the present invention provides a microwave heating device comprising a plurality of feeding ports with reduced crosstalk.

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Finspong, Sweden

Olle Niklasson