RF match detector circuit with dual directional coupler

摘要

A detector circuit for controlling an RF match circuit that receives an RF power signal from an RF source and delivers the RF power signal to a load. The RF match circuit includes a first variable reactance element which is controlled by a first control signal and a second variable reactance element is controlled by a second control signal. The detector circuit includes a dual directional coupler which generates a forward signal that is proportional to RF power delivered to the match circuit and a reflected signal that is proportional to RF power reflected back from the RF match circuit. The detector also includes a first branch circuit receiving the reflected signal and producing a first and second output signal therefrom and a second branch circuit receiving the forward signal and producing a first and second output signal therefrom. The detector further includes a first phase detector receiving the first output signals of the first and second branch circuits and generating a first phase detection output signal from which the first control signal is derived; and a second phase detector receiving the second output signals of the first and second branch circuits and generating a second phase detection output signal from which the second control signal is derived.