Patent ID: 6377119
Filing Date: 2002-04-23
Classification: H03F

Abstract:
A method for canceling a selected signal within a closed-loop control system, the closed-loop control system comprising an input signal, an element modifying said input signal, an output signal, and a feedback path, the method comprising the steps of:a) providing a selected signal to said feedback path, b) deriving a feedback signal from said feedback path, c) sensing one or more parameters of the system to be controlled and producing one or more control signals responsive to said sensing, d) applying the control signals to said selected signal, thereby deriving a cancellation signal, e) applying said cancellation signal to said feedback signal, thereby substantially canceling said selected signal from said feedback signal, and f) after said selected signal has been canceled from said feedback signal in the proceeding step, feeding back said feedback signal into said input signal modifying element, g) said control signals may be varied with time imposing said time variation on said cancellation signal and thereby on the amplitude and phase of a corresponding version of said selected signal present in the feedback path.