Using Noise Floor Extension in

Dynamic range is a core measure
of spectrum analyzer performance,
and can signifi  cantly affect other
core measures such as accuracy
and measurement speed. Spectrum
analyzers have many different
measures of dynamic range, and most
of these include noise, specifi  cally the
analyzer’s own internally-generated
noise. Reducing the effective analyzer
noise fl  oor therefore improves
dynamic range and the quality of
many measurements. 
Most spectrum analyzer users are
aware that any measurements made
near an analyzer’s displayed noise
level (within about 20 dB) will be
affected by noise. The analyzer’s
noise adds to the apparent power of
the signal to be measured, producing
a result that is somewhat higher than
the true fi  gure (on average) as shown
in Figure 1.