Patent attributes
A data processing method is provided to enable a calculation based signal analyzer, such as an FFT based spectrum analyzer, to produce results corresponding to a swept spectrum analyzer employing a video bandwidth (VBW) filter. Once a spectrum is produced the frequency axis is replace by a corresponding time axis, so that a time domain filter, such as a video bandwidth (VBW) filter can be applied. The filter characteristics are applied by performing an FFT to produce frequency domain data, multiplying by the frequency response to produce a filtered version, performing an inverse FFT and replacing the time axis with the original frequency axis to produce a filtered version of the display spectrum data.