Patent attributes
This disclosure describes systems, methods, and apparatus for frequency tuning a power source so as to optimize power delivery to a plasma load as well as systems, methods, and apparatus for identifying characteristics and/or changes in characteristics of a plasma load. In particular, a secondary power signal can be applied concurrently with a primary power signal, the secondary power signal having a substantially lower power level, so as to tune for a global optimum of a measure of performance and/or identifying characteristics and/or changes in characteristics of a plasma load. The secondary power signal can comprise a low level signal that is jointly generated with or combined with the primary power signal, or it can comprise noise either inherent to the primary power signal or added to the primary power signal.
