METHOD AND APPARATUS FOR CANCELLATION OF SPURIOUS SIGNALS

摘要

Systems and methods for generating a spurious signal cancellation signal, the system comprising two direct digital synthesizers (DDS). The first DDS provides phase tracking to correct for rounding errors. The second DDS outputs a frequency that is exactly equal to N/M*CLK, where N and M are values selected to set the output frequency equal to the frequency of a spurious signal to be cancelled, and CLK is a clock frequency used to clock the first and second DDS circuits.

主权项

1. A method for cancellation of spurious signals comprising:
a) determining the frequency and amplitude of a spurious signal to be cancelled; b) estimating the phase of the spurious signal; c) generating a cancellation signal using a first direct digital synthesizer (DDS); and d) adjusting the phase of the cancellation signal using a second DDS.