RF Energy Application to Rotating Chambers
Some exemplary aspects of the invention may be directed to an apparatus for processing an object by RF energy applied at a plurality of excitation setups. The apparatus may include a controller configured to select one or more excitation setups, from among a plurality of pilot excitation setups, for applying RF energy to a rotating chamber; and cause a source of RF energy to apply RF energy at the one or more selected excitation setups, wherein the controller is configured to both select the one or more excitation setups and cause the source of RF energy to apply RF energy to the one or more selected excitation setups at least twice during a single rotation of the rotating chamber. The apparatus may be a dryer.
1 . A method of processing an object by application of RF energy, the method comprising:
selecting, from among a plurality of excitation setups, one or more excitation setups for RF energy application to a rotating chamber configured to contain an object to be processed; and
applying RF energy at the one or more selected excitation setups, wherein the selecting and applying occurs at least twice during a single rotation of the chamber.
2 . The method of claim 1 , wherein the selecting and applying occurs at least twice during each of at least half of the rotations of the chamber.
3 . The method of claim 1 , wherein the selecting and applying occurs at least 10 times during a single rotation of the chamber.
4 . The method of claim 1 , wherein the selecting and applying occurs at least 10 times during each of at least half of the rotations of the chamber.
5 . The method of claim 1 , further comprising receiving electromagnetic (EM) feedback from the chamber, and wherein selecting the one or more excitation setups is based on the EM feedback.
6 . The method of claim 1 , wherein the one or more excitation setups are selected based on RF energy absorption characteristics of the plurality of excitation setups.
7 . The method of claim 1 , wherein the one or more selected excitation setups have RF energy absorption levels higher than other excitation setups included in the plurality of excitation setups.
8 . The method of claim 1 , wherein the one or more selected excitation setups have RF energy absorption levels higher than any of the other excitation setups of said plurality.
9 . The method of claim 1 , wherein selecting the one or more excitation setups comprises:
causing application of RF energy at two or more pilot excitation setups;
receiving EM feedback from the chamber; and
selecting the one or more excitation setups from among the pilot excitation setups based on the EM feedback.
10 . The method of claim 9 , wherein:
causing application of RF energy at two or more pilot excitation setups comprises applying RF energy at less than a first power level to the two or more pilot excitation setups; and
applying the RF energy at the one or more selected excitation setups comprises applying RF energy at the selected excitation setups at a power level higher than a second power level that is higher than the first power level.
11 . The method of claim 9 , wherein the EM feedback is indicative of an extent to which RF energy applied at the two or more pilot excitation setups can be absorbed in the chamber.
12 . The method of claim 11 , wherein the selected one or more excitation setups include those that, based on the EM feedback, exhibit energy absorbable values in the chamber greater than the pilot excitation setups not included in the one or more excitation setups.
13 . The method of claim 9 , wherein the one or more selected excitation setups are associated with RF energy absorption peaks having widths greater than a predetermined threshold.
14 . An apparatus for processing an object by RF energy applied at a plurality of excitation setups the apparatus comprising:
a controller configured to:
select one or more excitation setups, from among a plurality of pilot excitation setups, for applying RF energy to a rotating chamber; and
cause a source of RF energy to apply RF energy at the one or more selected excitation setups, wherein the controller is configured to both select the one or more excitation setups and cause the source of RF energy to apply RF energy to the one or more selected excitation setups at least twice during a single rotation of the rotating chamber.
15 . The apparatus of claim 14 , wherein the controller is configured to both select the one or more excitation setups and cause the source of RF energy to apply RF energy to the one or more selected excitation setups at least twice during at least half of the rotations of the rotating chamber.
16 . The apparatus of claim 14 , wherein the controller is configured to both select the one or more excitation setups and cause the source of RF energy to apply RF energy at the one or more selected excitation setups at least 10 times during a single rotation of the rotating chamber.
17 . The apparatus of claim 14 , wherein the controller is configured to both select the one or more excitation setups and cause the source of RF energy to apply RF energy to the one or more selected excitation setups at least 10 times during at least half of the rotations of the rotating chamber.
18 . The apparatus of claim 14 , wherein the controller is further configured to receive electromagnetic (EM) feedback from the rotating chamber and select the one or more excitation setups based on the EM feedback.
19 . The apparatus of claim 14 , wherein the controller is configured to select the one or more excitation setups based on RF energy absorption characteristics associated with the plurality of excitation setups.
20 . The apparatus of claim 14 , wherein the one or more selected excitation setups are each associated with RF energy absorption levels higher than RF energy absorption levels of other excitation setups of said plurality of pilot excitation setups not among the one or more selected excitation setups.
21 . The apparatus of claim 14 , wherein the controller is configured to:
cause application of RF energy at two or more pilot excitation setups;
receive EM feedback from the chamber; and
select the one or more selected excitation setups from among the pilot excitation setups based on the EM feedback.
22 . The apparatus of claim 21 , wherein the controller is configured to cause application of RF energy at the two or more pilot excitation setups at less than a first power level and apply the RF energy at the one or more selected excitation setups at a second power level that is higher than the first power level.
23 . The apparatus of claim 18 , wherein the feedback is indicative of an extent to which RF energy applied at the plurality of pilot excitation setups can be absorbed in the chamber.
24 . The apparatus of claim 21 , wherein the controller is configured to select the one or more excitation setups based on whether the one or more excitation setups are associated with RF energy absorption peaks having widths greater than a predetermined threshold.
25 . The apparatus of claim 14 , further comprising the source of RF energy.
26 . The apparatus of claim 14 , wherein the apparatus is a dryer.
27 . The apparatus of claim 14 , wherein the pilot excitation setups include excitation setups that differ from each other in a phase difference between emissions of two radiating elements.
28 . The apparatus of claim 14 , wherein the controller is configured to cause application of RF energy at the selected excitation setups for a total time duration larger by at least a factor of 5 than a total time duration for which RF energy is applied at the pilot excitation setups.
29 . The apparatus of claim 14 , wherein an average time duration of energy application per pilot excitation setup is at least 10 times shorter than an average time duration of energy application per selected excitation setup.
30 . The apparatus of claim 14 , wherein the applied RF energy falls only within one or more ISM frequency bands.