A method for clock spur artifact correction includes obtaining a plurality of switching stage input signals generated in accordance with an input signal level of an external amplifier, and adjusting the plurality of switching stage input signals such that a clock spur harmonic artifact is reduced. The clock spur harmonic artifact includes a first clock spur harmonic artifact generated in a plurality of external signal paths including external switching stages, and the adjusting the plurality of switching stage input signals includes one of: adjusting a duty ratio of one of the plurality of switching stage input signals in accordance with a gain mismatch between two of the external signal paths; and injecting a first Continuous Wave (CW) signal into the plurality of switching stage input signals in accordance with a previous amplitude of the first clock spur harmonic artifact.