DISTORTION CANCELLATION METHOD AND CIRCUIT

摘要

This invention provides methods and circuits for reducing or cancelling intermodulation distortion in a preceding circuit, using the output of the preceding circuit. In one embodiment the method includes generating, from the circuit output (i) a primary output including the intermodulation distortion and a fundamental signal of the preceding circuit; and (ii) an auxiliary output, including a portion of the intermodulation distortion that is substantially equivalent in magnitude and inverted relative to the intermodulation distortion in the primary output, and the fundamental signal; and summing the primary and auxiliary outputs; such that the portion of the intermodulation distortion is reduced or cancelled. In one embodiment the methods and circuits improve third-order linearity and attenuate or cancel odd-order intermodulation distortion products with minimal deterioration in the noise figure of the preceding circuit.