Signal processing system and power supply device having a signal processing system

A signal processing system comprising

• an acquisition device configured to acquire a repeating signal trace in a specified time interval, wherein the signal trace varies as a function of a plasma process state of a plasma process comprising a pulsed radio-frequency (RF) power signal,
• a synchronization device configured to synchronize the acquisition device to a signal trace frequency such that the specified time interval is synchronized to a pulse of the pulsed RF power signal;
• and
• a determining device configured to generate a data stream describing the plasma process, based on at least two signal traces acquired in one time interval each,
• wherein the data stream contains a continuously determined stability indicator for the plasma process,
• wherein the specified time interval of the repeating signal trace and/or a data stream interval are predetermined by process fluctuations of the plasma process,
• wherein the data stream is generated based on a comparison of the at least two acquired signal traces,
• wherein the determining device is configured to generate and output to a user the data stream including the stability indicator, and
• wherein a value of the stability indicator is based on a distance of a respective signal trace of the at least two acquired signal traces in comparison to one of:
• a mean value, a maximum value, or a minimum value of an acquired signal trace of the at least two acquired signal traces acquired over a previous time interval.