Applying RF energy according to time variations in EM feedback

1. A method of processing an object in a cavity by applying radio frequency (RF) energy to the cavity, the method comprising:

identifying a first plurality of frequencies, characterized in that a time derivative of a value indicative of a dielectric response of the cavity to RF energy at frequency of the first plurality of frequencies is larger than a first threshold; and

applying more energy at frequencies of the first plurality of frequencies than at other frequencies.

2. The method of claim 1 , wherein less energy is applied at a second plurality of frequencies than at the first plurality of frequencies, wherein frequencies of the second plurality of frequencies being characterized in that a time derivative of the value indicative of the dielectric response of the cavity to RF energy at frequencies of the first plurality of frequencies is larger than a second threshold, wherein the second threshold is higher than the first threshold.

3. The method of claim 1 , wherein applying more energy than at other frequencies comprises applying energy at a higher power level than a power level at which energy is applied at any one of the other frequencies.

4. The method of claim 1 , wherein applying more energy than at other frequencies comprises applying energy for a longer duration than a duration for which energy is applied at any one of the other frequencies.

5. The method of claim 1 , wherein the value indicative of a dielectric response of the cavity to RF energy comprises a network parameter.

6. The method of claim 1 , wherein the value indicative of a dielectric response of the cavity to RF energy is derivable from one or more network parameters.

7. The method of claim 1 , wherein the applying results in heating the object.

8. The method of claim 1 , wherein the identifying is performed by a processor.

9. The method of claim 1 , wherein a processor causes the applying.

10. A method of processing an object in a cavity by applying radio frequency (RF) energy to the cavity, the method comprising:

identifying a first plurality of modulation space elements (MSEs), each MSE being a set of one or more controllable parameters that affect a field pattern excited in the cavity, characterized in that a time derivative of a value indicative of a dielectric response of the cavity to RF energy at MSE of the first plurality of MSEs is larger than a first threshold; and

applying more energy at MSEs of the first plurality of MSEs than at other MSEs.

11. The method of claim 10 , wherein less energy is applied at a second plurality of MSEs than at the first plurality of MSEs, wherein MSEs of the second plurality of MSEs being characterized in that a time derivative of the value indicative of the dielectric response of the cavity to RF energy at MSEs of the first plurality of MSEs is larger than a second threshold, wherein the second threshold is higher than the first threshold.

12. The method of claim 10 , wherein applying more energy than at other MSEs comprises applying energy at a higher power level than a power level at which energy is applied at any one of the other MSEs.

13. The method of claim 10 , wherein applying more energy than at other MSEs comprises applying energy for a longer duration than a duration for which energy is applied at any one of the other MSEs.

14. The method of claim 10 , wherein the value indicative of a dielectric response of the cavity to RF energy comprises a network parameter.

15. The method of claim 10 , wherein the value indicative of a dielectric response of the cavity to RF energy is derivable from one or more network parameters.

16. The method of claim 10 , wherein the set of one or more controllable parameters comprises a phase difference, a relative amplitude, or both a phase difference and a relative amplitude.

17. The method of claim 16 , wherein the set of one or more controllable parameters further comprises a frequency.