RF energy application based on absorption peaks
An object is processed in a cavity resonator by application of radiofrequency energy to the cavity resonator through a plurality of feeds. Excitation setups are grouped into a plurality of peaks based on values of an absorbability indicator associated with each of the excitation setups. At least one peak among the plurality of peaks is selected based on the values of the absorbability indicator associated with the excitation setups grouped into each peak. Radiofrequency energy is applied to the cavity resonator based on the selection, in which the excitation setups are multi-dimensional.
1. An apparatus for processing an object in a cavity resonator by application of radiofrequency (RF) energy to the cavity resonator through a plurality of feeds, the apparatus comprising:
a source of RF energy;
a detector configured to detect RF signals going out of the cavity resonator; and
a processor configured to receive input from the detector and control the source of RF energy to excite in the cavity resonator RF fields at different excitation setups based on the input received from the detector,
wherein the processor is configured to:
associate with each excitation setup a value of an absorbability indicator;
group excitation setups into a plurality of peaks based on values of absorbability indicator associated with each of the excitation setups;
select at least one peak among the plurality of peaks based on the values of the absorbability indicator associated with the excitation setups grouped into each peak; and
cause the source of RF energy to apply the RF energy to the cavity resonator based on the selection,
wherein the excitation setups are multi-dimensional,
wherein the source of RF energy comprises a plurality of synchronized RF energy sources controlled to feed the plurality of feeds with signals having a common frequency at one or both of a controlled phase difference and a controlled amplitude difference, and
wherein the signals are emitted during overlapping time periods.
2. The apparatus of claim 1 , wherein the RF energy source comprises a phase modulator controllable by the processor and configured to modulate a phase of a signal before the signal is applied to the cavity resonator, and one dimension of the multi-dimensional excitation setups is a phase difference between RF fields emitted by two of the plurality of feeds.
3. The apparatus of claim 1 , wherein the processor controls the source of RF energy to apply the RF energy to the resonant cavity only at selected excitation setups.
4. The apparatus of claim 1 , wherein the processor is configured to select among the peaks according to relations between the selected peaks and other peaks.
5. The apparatus of claim 1 , wherein the processor is configured to select a predetermined number of peaks.
6. The apparatus of claim 1 , wherein the processor is configured to select a predetermined portion of the peaks.
7. The apparatus of claim 1 , wherein the absorbability indicator comprises a ratio of energy absorbed by the object to energy supplied to the plurality of feeds.
8. The apparatus of claim 1 , wherein the absorbability indicator comprises a ratio of a sum of powers supplied to the plurality of feeds that emit energy simultaneously at a given frequency to the sum of power received by the plurality of feeds.
9. An apparatus for processing an object in a cavity resonator by application of radiofrequency (RF) energy to the cavity resonator through a plurality of feeds, the apparatus comprising:
a source of RF energy;
a detector configured to detect RF signals going out of the cavity resonator; and
a processor configured to receive input from the detector and control the source of RF energy to excite in the cavity resonator RF fields at different excitation setups based on the input received from the detector,
wherein the processor is configured to:
associate with each excitation setup a value of an absorbability indicator;
group excitation setups into a plurality of peaks based on values of absorbability indicator associated with each of the excitation setups;
select at least one peak among the plurality of peaks based on the values of the absorbability indicator associated with the excitation setups grouped into each peak; and
cause the source of RF energy to apply the RF energy to the cavity resonator based on the selection,
wherein the excitation setups are multi-dimensional,
wherein the RF energy source comprises a phase modulator controllable by the processor and configured to modulate a phase of a signal before the signal is applied to the cavity resonator, and one dimension of the multi-dimensional excitation setups is a phase difference between RF fields emitted by two of the plurality of feeds, and
wherein a curve of the values of the absorbability indicator versus the phase difference has a maximum at each peak.