A radio frequency system comprising: a power amplifier configured to generate and to output a radio frequency signal to a matching network via a transmission line between the power amplifier and the matching network ; a first sensor for monitoring the radio frequency signal and generating first sensor signals based on the radio frequency signal , 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 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 configured to generate and to output a radio frequency signal to a matching network via a transmission line between the power amplifier and the matching network ; a first sensor for monitoring the radio frequency signal and generating first sensor signals based on the radio frequency signal , 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 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. <EOS>