# US 9,040,883 B2 · Electromagnetic heating > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 9,040,883 B2 - Document ID: US9040883B2 - Status: Granted - Kind: B2 - Application number: 12/563,182 - Filed: 2009-09-21 - Published: 2010-01-14 - Granted: 2015-05-26 - Earliest claimed: 2006-02-21 - Assignees: Goji Limited - Applicants: Eran Ben-Shmuel; Alexander Bilchinsky - Inventors: Eran Ben-Shmuel; Alexander Bilchinsky - Web page: https://patentgrep.com/patent/US9040883B2 ## CPC - H05B 6/666: {Safety circuits (emergency protective circuits in general H02H)} - H05B 6/647: {Aspects related to microwave heating combined with other heating techniques} - H05B 6/705: {using microwave tuning} - H05B 2206/044: Microwave heating devices provided with two or more magnetrons or microwave sources of other kind - Y02B 40/00: Technologies aiming at improving the efficiency of home appliances, e.g. induction cooking or efficient technologies for refrigerators, freezers or dish washers - H05B: ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL - Y02B: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS ## Abstract An electromagnetic heater for heating an irregularly shaped object, including: a cavity within which an object is to be placed; at least one feed which feeds UHF or microwave energy into the cavity; and a controller that controls one or more characteristics of the cavity or energy to assure that the UHF or microwave energy is deposited uniformly in the object within ±30% over at least 80% of the volume of the object. ## Claims ### Claim 1 An apparatus for electromagnetically heating an object in a cavity, the apparatus comprising: a plurality of feeds configured to feed UHF (Ultra High Frequency) or microwave energy into the cavity; at least one detector configured to measure power coupled between at least two feeds from among the plurality of feeds during a sweep over a plurality of frequencies within a frequency band; and a controller configured to: determine, for each of the plurality of frequencies within the frequency band, a heating efficiency based on the measured power coupled between the at least two feeds from among the plurality of feeds; and control one or more characteristics of the heating process based on the determined heating efficiency for each of the plurality of frequencies within the frequency band. ### Claim 2 (depends on 1) The apparatus of claim 1, wherein the one or more characteristics of the heating process comprise an amount of energy fed into the cavity. ### Claim 3 (depends on 1) The apparatus of claim 1, wherein the one or more characteristics of the heating process comprise an input power level at each transmitted frequency. ### Claim 4 (depends on 1) The apparatus of claim 1, wherein the controller is configured to control the one or more characteristics of the heating process by choosing frequencies at which the energy is fed into the cavity. ### Claim 5 (depends on 1) The apparatus of claim 1, wherein the controller is configured to control the one or more characteristics of the heating process by causing movement of the object in the cavity. ### Claim 6 (depends on 1) The apparatus of claim 1, wherein the one or more characteristics of the heating process comprises one or more antenna characteristics. ### Claim 7 (depends on 1) The apparatus of claim 1, wherein the controller is configured to determine the heating efficiency based on return loss. ### Claim 8 (depends on 1) The apparatus of claim 1, wherein the controller is configured to adjust energy application to a first feed based on power coupled between the first feed and at least one second feed. ### Claim 9 (depends on 1) The apparatus of claim 1, wherein the controller is configured to control the one or more characteristics based on changes in the object. ### Claim 10 (depends on 1) The apparatus of claim 1, wherein the controller is configured to determine the heating efficiency based on S parameters indicative of the coupled power. ### Claim 11 (depends on 1) The apparatus of claim 1, wherein the controller is configured to adjust the one or more characteristics of the heating process one or more times during the heating process. ### Claim 12 (depends on 1) The apparatus of claim 1, wherein the controller is configured to control the one or more characteristics based on measurements of energy absorption during the heating process or during a hiatus in the heating process. ### Claim 13 A method for electromagnetically heating an object in a cavity, the method comprising: feeding UHF (Ultra High Frequency) or microwave energy into the cavity through a plurality of feeds; measuring power coupled between at least two feeds from among the plurality of feeds, during a sweep over a plurality of frequencies within a frequency band; using a controller to determine, for each of the plurality of frequencies within the frequency band, a heating efficiency based on the measured power coupled between the at least two feeds from among the plurality of feeds; and controlling one or more characteristics of the heating process based on the determined heating efficiency for each of the plurality of frequencies within the frequency band. ### Claim 14 (depends on 13) The method of claim 13, wherein the one or more characteristics of the heating process comprise an amount of energy fed into the cavity. ### Claim 15 (depends on 13) The method of claim 13, wherein the one or more characteristics of the heating process comprise an input power level at each transmitted frequency. ### Claim 16 (depends on 13) The method of claim 13, wherein controlling the one or more characteristics of the heating process comprises choosing frequencies at which the energy is fed into the cavity. ### Claim 17 (depends on 13) The method of claim 13, wherein controlling the one or more characteristics of the heating process comprises moving the object in the cavity. ### Claim 18 (depends on 13) The method of claim 13, wherein the one or more characteristics of the heating process comprises one or more antenna characteristics. ### Claim 19 (depends on 13) The method of claim 13, wherein determining the heating efficiency further comprises determining based on return loss. ### Claim 20 (depends on 13) The method of claim 13, comprising adjusting energy application to a first feed based on coupled power between the first feed and at least one second feed. ### Claim 21 (depends on 13) The method of claim 13, wherein controlling the one or more characteristics comprises controlling based on changes in the object. ### Claim 22 (depends on 13) The method of claim 13, wherein determining the heating efficiency comprises determining based on S parameters indicative of the coupled power. ### Claim 23 (depends on 13) The method of claim 13, wherein controlling the one or more characteristics of the heating process is repeated one or more times during the heating process. ### Claim 24 (depends on 13) The method of claim 13, comprising controlling the one or more characteristics of the heating process based on measurements of energy absorption during the heating process or during a hiatus in the heating process. ### Claim 25 (depends on 1) The apparatus of claim 1, wherein each of the feeds includes an antenna. ### Claim 26 (depends on 13) The method of claim 13, wherein each of the feeds includes an antenna. ### Claim 27 An apparatus for electromagnetically heating an object in a cavity, the apparatus comprising: a plurality of antennas configured to feed UHF (Ultra High Frequency) or microwave energy into the cavity at a plurality of frequencies; at least one detector configured to measure power coupled between at least two antennas from among the plurality of antennas during a sweep over a plurality of frequencies within a frequency band; and a controller configured to: determine, for each of the plurality of frequencies within the frequency band, the measured power coupled between the at least two antennas from among the plurality of antennas; and control one or more characteristics of the heating process based on the measured power determined at one or more of the plurality of frequencies within the frequency band. ### Claim 28 A method for electromagnetically heating an object in a cavity, the method comprising: feeding UHF (Ultra High Frequency) or microwave energy into the cavity at a plurality of frequencies through a plurality of antennas; measuring power coupled between at least two of antennas from among the plurality of antennas, during a sweep over a plurality of frequencies within a frequency band; using a controller to determine, for each of the plurality of frequencies within the frequency band, the measured power coupled between the at least two antennas from among the plurality of antennas; and controlling one or more characteristics of the heating process based on the measured power determined at one or more of the plurality of frequencies within the frequency band.