Method and apparatus of eliminating interference in an undersettled electrical signal

A method of eliminating interference from an undersettled electrical signal, the undersettled electrical signal including a test signal at a known frequency, comprising the steps of:

• providing a digitized version of said undersettled electrical signal;
• generating a frequency spectrum of said digitized version of said undersettled electrical signal, said frequency spectrum having a spectrum component at said known frequency, said spectrum component including a test signal component and an unknown interference signal component;
• spectrally interpolating said frequency spectrum to eliminate said test signal component from said frequency spectrum to form an interference signal spectrum;
• and
• subtracting said interference signal spectrum from said frequency spectrum to form a settled signal spectrum.

A method of eliminating interference from an undersettled electrical signal, the undersettled electrical signal including a test signal at a known frequency, comprising the steps of:

• providing a digitized version of said undersettled electrical signal;
• generating a frequency spectrum of said digitized version of said undersettled signal, said frequency spectrum having a spectrum component at said known frequency, said spectrum component including a test signal component and an unknown interference signal component;
• determining said unknown interference signal component by spectral interpolation;
• replacing said spectrum component at said known frequency with said unknown interference signal component to form an interference signal spectrum;
• and
• subtracting said interference signal spectrum from said frequency spectrum to form a settled signal spectrum.

A method of testing an electrical device having an undersettled signal output, said undersettled signal output including a test signal generated at a known frequency, comprising the steps of:

• providing a digitized version of the undersettled signal output;
• generating a frequency spectrum of said digitized version of said undersettled signal, said frequency spectrum having a spectrum component at said known frequency, said spectrum component comprising a test signal component and an unknown interference signal component;
• spectrally interpolating said frequency spectrum to remove said test signal component from said frequency spectrum to form an interference signal spectrum;
• subtracting said interference signal spectrum from said frequency spectrum of said undersettled signal to generate a settled signal spectrum;
• and
• performing at least one performance test on the electrical device using said settled signal spectrum.

A system for eliminating interference from an undersettled electrical signal, said undersettled electrical signal including a test signal generated at a known frequency, comprising:

• first means responsive to said undersettled electrical signal for producing a digitized version of said undersettled electrical signal;
• second means responsive to said digitized version of said undersettled electrical signal for transforming said digitized version of said undersettled electrical signal into a transformed signal;
• third means responsive to said transformed signal for spectrally interpolating said transformed signal to form an interference signal;
• and
• fourth means responsive to said interference signal and said transformed signal for eliminating said interference signal from said transformed signal generating said settled signal output.