Impedance matching in a RF power generation system

An impedance matching network including a mixing module. The mixing module receives a plurality admittances based upon at least one parameter sensed from an output which generated by an RF generator. The output signal is a pulsed RF signal having a plurality of states for each pulse and the plurality of admittances correspond to the plurality states. The mixing module generates a virtual admittance determined in accordance with the plurality of admittances adjusted by a gain. The impedance matching module receives the virtual admittance and generates a command to adjust a capacitance of the impedance matching network or a command to adjust a frequency of the output signal in accordance with the virtual admittance.