Specifications

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Residual responses: Discrete responses seen on a spectrum analyzer display
with no input signal present.
Resolution: See Frequency resolution.
Resolution bandwidth: The width of the resolution bandwidth (IF) filter
of a spectrum analyzer at some level below the minimum insertion loss
point (maximum deflection point on the display). For Agilent analyzers,
the 3 dB bandwidth is specified; for some others, it is the 6 dB bandwidth.
Rosenfell: The display detection mode in which the value displayed at each
point is based upon whether or not the video signal both rose and fell during
the frequency and/or time interval represented by the point. If the video
signal only rose or only fell, the maximum value is displayed. If the video
signal did both rise and fall, then the maximum value during the interval is
displayed by odd-numbered points, the minimum value, by even-numbered
points. To prevent the loss of a signal that occurs only in an even-numbered
interval, the maximum value during this interval is preserved, and in the
next (odd-numbered) interval, the displayed value is the greater of either
the value carried over or the maximum that occurs in the current interval.
Sample: The display detection mode in which the value displayed at each
point is the instantaneous value of the video signal at the end of the
frequency span and/or time interval represented by the point.
Scale factor: The per-division calibration of the vertical axis of the display.
Sensitivity: The level of the smallest sinusoid that can be observed on a
spectrum analyzer, usually under optimized conditions of minimum
resolution bandwidth, 0 dB RF input attenuation, and minimum video
bandwidth. Agilent defines sensitivity as the displayed average noise level.
A sinusoid at that level will appear to be about 2 dB above the noise.
Shape factor: See Bandwidth selectivity.
Signal identification: A routine, either manual or automatic, that indicates
whether or not a particular response on the spectrum analyzer’s display
is from the mixing mode for which the display is calibrated. If automatic,
the routine may change the analyzer’s tuning to show the signal on the
correct mixing mode, or it may tell us the signal’s frequency and give us
the option of ignoring the signal or having the analyzer tune itself properly
for the signal. Generally not needed on preselected analyzers.
Span accuracy: The uncertainty of the indicated frequency separation of
any two signals on the display.
Spectral purity: See Noise sidebands.
Spectral component: One of the sine waves comprising a spectrum.