Noise based frequency tuning and identification of plasma characteristics

A power generation system configured for automated frequency tuning of power delivered to a plasma load, the power generation system comprising:

• a power source to apply a primary power signal to an output, the output configured for coupling to a plasma load, either directly or through a matching network, the power source is configured to apply one or more secondary power signals at one or more or a continuum of secondary frequencies to the plasma load, wherein power produced at the secondary frequencies is lower than power produced at the primary frequency;
• a sensor arranged to sense one or more attributes of power delivered to the plasma load to obtain a measure of performance;
• a global optimum identification module that including a non-transitory, tangible processor readable storage medium, encoded with instructions that are readable by a processor or a field programmable gate array to perform a method for automated frequency tuning of a power generation system, the method comprising:
• applying a primary power signal at a primary frequency to a plasma load with the power source, either directly or through a matching network;
• concurrently applying one or more secondary power signals at one or more or a continuum of secondary frequencies to the plasma load;
• monitoring a measure of performance;
• identifying an optimum frequency corresponding to a global optimum of the measure of performance;
• and
• adjusting the primary frequency towards the optimum frequency.