Common analysis and display functions
R&S
®
FSVA3000/ R&S
®
FSV3000
536
User Manual 1178.8520.02 ─ 08
Correction factors
The R&S
FSV/A uses the following correction factors to analyze the noise density from
the marker level:
●
Since the noise power is indicated with reference to 1
Hz bandwidth, the bandwidth
correction value is deducted from the marker level. It is 10
x
lg (1
Hz/BWNoise),
where BWNoise is the noise or power bandwidth of the set resolution filter (RBW).
●
RMS detector: With the exception of bandwidth correction, no further corrections
are required since this detector already indicates the power for each point of the
trace.
●
Sample detector: As a result of video filter averaging and trace averaging, 1.05
dB
is added to the marker level. This is the difference between the average value and
the RMS value of white noise. With a logarithmic level axis, 1.45
dB is added addi-
tionally. Logarithmic averaging is thus fully taken into account, which yields a value
that is 1.45
dB lower than that of linear averaging.
●
To allow for a more stable noise display, eight trace points on each side of the mea-
surement frequency are averaged.
●
For span > 0, the measured values are averaged versus time (after a sweep).
The R&S
FSV/A noise figure can be calculated from the measured power density level.
It is calculated by deducting the set RF attenuation (RF Att) from the displayed noise
level and adding 174 to the result.
The individual marker settings correspond to those defined in the "Marker" dialog box
(see
Chapter 7.3.2.1, "Individual marker setup"
on page 520). Any settings to the
marker state or type changed in the "Marker Function" dialog box are also changed in
the "Marker" dialog box and vice versa.
Marker usage
