US Patent 11315758 Impedance matching using electronically variable capacitance and frequency considerations

In one embodiment, the present disclosure is directed to an RF impedance matching network that includes an electronically variable capacitor (EVC) and a control circuit. The control circuit is coupled to a sensor configured to detecting an RF parameter. To cause an impedance match between an RF source and a plasma chamber, the control circuit determines, using a match lookup table with a value based on the detected RF parameter, a match combination of a new EVC configuration for providing a new EVC capacitance, and a new source frequency for the RF source. The control circuit then alters the EVC to the new EVC configuration, and alters the variable frequency of the RF source to the new source frequency.