A two-dimensional frequency search grid is defined by a first coordinate axis representing an operating frequency setpoint of an RF signal generator in a first operational state and a second coordinate axis representing an operating frequency setpoint of the RF signal generator in a second operational state. The RF signal generator has a first output power level in the first operational state and a second output power level in the second operational state. The RF signal generator operates in an multi-level RF power pulsing mode by cyclically alternating between the first operational state and the second operational state. An automated search process is performed within the two-dimensional frequency search grid to simultaneously determine an optimum value for the operating frequency setpoint of the RF signal generator in the first operational state and an optimum value for the operating frequency setpoint of the RF signal generator in the second operational state.