DEVICE AND METHOD FOR CONTROLLING ENERGY
A method of irradiating a load comprising providing different amounts of energy at different frequencies by varying respective durations during which corresponding frequencies are transmitted. The method is useful for any form of heating including warming, drying and thawing using microwave and/or RF energy.
1 - 27 . (canceled)
28 . A method of irradiating a load comprising:
selecting a respective duration for each of a plurality of frequencies at which radiation is to be transmitted;
obtaining dissipation information associated with the load;
setting desired energy amounts to be dissipated in the load at each of the plurality of frequencies according to the dissipation information; and
adjusting one or more of the respective durations according to the desired energy amounts.
29 . The method of claim 28 , wherein irradiating is performed over all frequencies in a working band.
30 . The method of claim 28 , further comprising:
defining a maximal amount of power that can dissipate in a load in a unit of time at each of the plurality of frequencies as a function of a dissipation information at that frequency and a maximum power level available from a power source at that frequency.
31 . The method of claim 28 , further comprising:
setting a lower transmitted power limit for irradiating the load.
32 . The method of claim 28 , wherein irradiating the load is performed in a resonance cavity.
33 . The method of claim 28 , wherein the irradiating the load is controlled for obtaining a predetermined energy dissipation pattern in the load.
34 . The method of claim 33 , wherein the predetermined energy dissipation pattern essentially corresponds to homogeneous energy dissipation in the load.
35 . The method of claim 33 , wherein the predetermined energy dissipation pattern comprises controlled non-homogeneous energy dissipation in the load.
36 . The method of claim 28 , wherein irradiating the load is performed at a fixed power transmission level.
37 . The method of claim 28 , wherein irradiating the load is performed at a maximal power transmission level for each of the plurality of frequencies, respectively.
38 . The method of claim 28 , wherein irradiating the load is controlled for limiting a maximum amount of energy provided at each of the plurality of frequencies.
39 . The method of claim 28 , wherein irradiating the load is controlled for limiting an overall amount of energy provided at different frequencies for a period of transmission.
40 . The method of claim 39 , wherein the period of transmission comprises a transmission cycle.
41 . The method claim 28 , wherein the irradiating the load is controlled over the respective durations.
42 . The method of claim 28 , wherein irradiating the load is controlled for maximizing power at each of the plurality of frequencies.
43 . The method of claim 28 , wherein radiation is transmitted at two or more of the plurality of frequencies and at two or more different non-zero power levels.
44 . A method of irradiating a load, comprising:
irradiating the load with radiation over a spectrum of frequencies;
measuring a resulting reflected and coupled spectrum (RC spectrum);
determining dissipation information associated with the load in view of the RC spectrum; and
setting the spectrum of frequencies based on the dissipation information wherein setting comprises transmitting different amounts of energy at different frequencies by varying respective durations during which radiation is transmitted at the different frequencies.
45 . The method of claim 44 , further comprising compensating for frequencies having low energy dissipation by increasing the respective durations during which radiation is transmitted at those frequencies.
46 . The method of claim 28 , wherein plurality of frequencies are arranged in a series to form a duty cycle.
47 . The method according to claim 46 , further comprising repetitively performing the duty cycle.
48 . The method of claim 47 , wherein the frequencies are varied within the duty cycle.
49 . The method of claim 48 , comprising switching frequencies differentially on or off over repetitions of the duty cycle to vary overall durations of irradiation at respective frequencies of irradiation of the load.
50 . The method of claim 49 , wherein the differentially switching comprises switching a frequency off for some of the cycles or to a lower power for some of the cycles.
51 . An apparatus for irradiating a load via at least one energy feed for transmitting energy to a cavity at a plurality of frequencies, comprising:
a controller for selecting respective durations of transmission for each of the plurality of frequencies;
wherein the controller is configured to obtain dissipation information associated with the load, to set desired energy levels to be dissipated in the load at the plurality of frequencies based on the dissipation information, and to adjust the durations according to the desired energy levels.
52 . The apparatus of claim 51 , further comprising at least one energy feed for transmitting energy to a cavity at a plurality of frequencies.
53 . The apparatus of claim 51 , further comprising a cavity.
54 . The apparatus of claim 51 , wherein the controller is configured to carry out selecting repeatedly.
55 . The apparatus of claim 51 , wherein the controller is configured to:
cause irradiation of the load over the plurality of frequencies, which include an irradiation spectrum of frequencies, for the respective durations,
determine a resulting reflected and coupled spectrum (RC spectrum),
determine dissipation information associated with the load in view of the RC spectrum, and
adjust the irradiation spectrum of frequencies based on the dissipation information.
56 . The apparatus of claim 51 , wherein the controller is configured to switch frequencies differentially on or off over repetitions of a duty cycle of the plurality of frequencies to vary the durations.
57 . The apparatus of claim 51 , wherein the controller is further configured to compensate for frequencies having low energy dissipation by increasing the respective durations during which radiation is transmitted at those frequencies.
58 . A method of irradiating a load comprising:
obtaining dissipation information from the load;
selecting respective durations during which radiation is transmitted over a plurality of frequencies such that radiation transmitted at a first frequency associated with a first dissipation level occurs over a duration longer than a duration during which radiation is transmitted at a second frequency associated with a second dissipation level greater than the first dissipation level; and
irradiating the load over the plurality of frequencies and for the respective durations.
59 . An apparatus for irradiating a load via at least one energy feed for transmitting energy to a cavity at a plurality of frequencies, comprising:
a processor configured to:
obtain dissipation information from the load;
select respective durations during which radiation is transmitted over a plurality of frequencies such that radiation transmitted at a first frequency associated with a first dissipation level occurs over a duration longer than a duration during which radiation is transmitted at a second frequency associated with a second dissipation level greater than the first dissipation level; and
cause irradiation of the load with energy over the plurality of frequencies and for the respective durations.