Patent ID: 7831226

Claim:
An impedance matching system comprising: a signal extractor to extract an output signal and an input signal having at least a portion of an electric current outputted through a load and at least a portion of an electric current inputted through the load, respectively; a processor to process the output signal and the input signal extracted from the signal extractor; a comparator to compare a phase and an amplitude of the output signal with a phase and an amplitude of the input signal, respectively; a coefficient calculator to calculate a reflection coefficient using the comparative result provided from the comparator; and a circuit controller to generate a signal for controlling a matching circuit, which matches the phase and the amplitude of the output signal with the phase and the amplitude of the input signal, respectively, so as to ensure the reflection coefficient to have a predetermined value, wherein the processor firstly filters the output signal and the input signal by low-pass filtering, and then secondly filters the output signal and the input signal by band-pass filtering.