Impedance matching system that has a transformer and method for tuning a system using a transformer

摘要

A system that includes an amplification circuit; a resonant circuit that is arranged to receive the amplified signal and to output an resonant circuit output signal; wherein the resonant circuit comprises a continually tuned variable capacitor; a transformer that is arranged to receive the resonant circuit output signal and to output a transformer output signal; a coupler that is arranged to sample the transformer output signal and a reflected signal and to output a first signal that represents the transformer output signal and a second signal that represents a reflected signal; a detector that is arranged to receive the first and second signals and to output an impedance indicative signal a control circuit that is arranged to generate the resonant circuit tuning signal in response to the impedance indicative signal and for compensating for the impedance mismatch.

主权项

1. A system comprising:
an amplification circuit that is arranged to amplify an input signal for providing an amplified signal; a variable resonant circuit that is arranged to receive the amplified signal and to output a variable resonant circuit output signal; wherein the variable resonant circuit comprises a variable capacitor that is a continually tuned variable capacitor; a transformer that is arranged to receive the variable resonant circuit output signal and to output a transformer output signal; a coupler that is arranged to sample the transformer output signal and a reflected signal and to output a first signal that represents the transformer output signal and a second signal that represents the reflected signal; a detector that is arranged to receive the first and second signals and to output an impedance indicative signal that is indicative of an impedance mismatch between an output impedance of the amplification circuit as seen after the transformer and an input impedance of a radio frequency (RF) antenna as seen by the amplification circuit; wherein the RF antenna is coupled to an output port of the coupler; wherein the variable resonant circuit is arranged to receive a variable resonant circuit tuning signal and to set an impedance of the variable resonant circuit in response to the variable resonant circuit tuning signal; and a control circuit that is arranged to generate the variable resonant circuit tuning signal in response to the impedance indicative signal and for compensating for the impedance mismatch.