Method for reducing harmonic distortion in an analog-to-digital converter system

In a system including an analog-to-digital converter, a method for reducing an amplitude of a distortion-generated signal related to an input signal, comprising:

• digitizing a signal spectrum of the input signal with the analog-to-digital converter to provide a normal frequency-domain data record having a first center frequency datum with a first amplitude and a first distortion-generated signal datum with a second amplitude;
• shifting by multiple amounts a frequency spectrum of the digitized input signal to provide multiple corresponding shifted frequency-domain data records each having a corresponding second center frequency with the first amplitude and a corresponding second distortion-generated signal datum with the second amplitude;
• realigning the multiple shifted frequency-domain data records to provide multiple corresponding realigned frequency-domain data records each having a realigned center frequency substantially equaling the first center frequency;
• and
• combining the normal frequency-domain data record and the multiple realigned frequency-domain data records to provide a combined frequency-domain data record in which the combined first and multiple realigned center frequency data have substantially the first amplitude and the first and multiple second distortion-generated signal data each have a third amplitude that is less than the second amplitude.