 In the fixed-tuned mode the range of frequencies downconverted does not change and the downconverter output is then digitized for further analysis.The digitizing process typically involves in-phase/quadrature (I/Q) or complex sampling so that all characteristics of the signal are preserved, as opposed to the magnitude-only processing of a spectrum analyzer.The sampling rate of the digitizing process may be varied in relation to the frequency span under consideration or (more typically) the signal may be digitally resampled.