A radio frequency system (10, 100) comprising: a power amplifier (20, 106) configured to generate and to output a radio frequency signal (17, 104) to a matching network via a transmission line between the power amplifier (20, 106) and the matching network; a first sensor for monitoring the radio frequency signal (17, 104) and generating first sensor signals based on the radio frequency signal (17, 104), the first sensor signal including voltage and current signals or forward and reverse power signals; a first distortion module for receiving the first sensor signals and determining a first distortion value according to at least one of (i) a sinusoidal function of the first sensor signals without directly detecting or adjusting the phase between the voltage and current outputs of the RF power amplifier (20, 106) or (ii) a cross-correlation function of the first sensor signals; and a first correction circuit for generating a first impedance tuning value based on the first distortion value and a first predetermined value, and for providing feedforward control of impedance matching performed within the matching network including outputting the first impedance tuning value to the matching network, wherein the first correction circuit comprises: a first input module for generating the first predetermined value; a first summer for summing the first distortion value and the first predetermined value to generate a first correction value; and a tune control module for generating the first impedance tuning value based on the first correction value. a power amplifier (20, 106) configured to generate and to output a radio frequency signal (17, 104) to a matching network via a transmission line between the power amplifier (20, 106) and the matching network; a first sensor for monitoring the radio frequency signal (17, 104) and generating first sensor signals based on the radio frequency signal (17, 104), the first sensor signal including voltage and current signals or forward and reverse power signals; a first distortion module for receiving the first sensor signals and determining a first distortion value according to at least one of (i) a sinusoidal function of the first sensor signals without directly detecting or adjusting the phase between the voltage and current outputs of the RF power amplifier (20, 106) or (ii) a cross-correlation function of the first sensor signals; and a first correction circuit for generating a first impedance tuning value based on the first distortion value and a first predetermined value, and for providing feedforward control of impedance matching performed within the matching network including outputting the first impedance tuning value to the matching network, wherein the first correction circuit comprises: a first input module for generating the first predetermined value; a first summer for summing the first distortion value and the first predetermined value to generate a first correction value; and a tune control module for generating the first impedance tuning value based on the first correction value. a first input module for generating the first predetermined value; a first summer for summing the first distortion value and the first predetermined value to generate a first correction value; and a tune control module for generating the first impedance tuning value based on the first correction value.