R&S ESR Series, Руководство пользователя

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Spectrum Measurements
R&S
®
ESR
393 User Manual 1175.7068.02 ─ 12
Remote command:
DET CAV
, see
[SENSe:][WINDow:]DETector<trace>[:FUNCtion]
on page 853
RMS Average ← Detector ← Trace 1/Trace 2/Trace 3/Trace 4/Trace 5/Trace 6
Selects the "RMS Average" detector.
Remote command:
DET CRMS
, see
[SENSe:][WINDow:]DETector<trace>[:FUNCtion]
on page 853
Average Mode
Opens a submenu to select the averaging method for the average trace mode. The fol-
lowing methods are available:
●
Lin
●
Log
●
Power
Logarithmic averaging is recommended to display signals with a low signal to noise
ratio. While positive peak values are decreased in logarithmic averaging due to the
characteristics involved, it is also true that negative peaks are increased relative to the
average value. If the distorted amplitude distribution is averaged, a value is obtained
that is smaller than the actual average value. The difference is -2.5
dB.
This low average value is usually corrected in noise power measurements by a 2.5 dB
factor. Therefore the R&S ESR offers the selection of linear averaging. The trace data
is converted to linear values prior to averaging, then averaged and reconverted to loga-
rithmic values. After these conversions the data is displayed on the screen. The aver-
age value is always correctly displayed irrespective of the signal characteristic.
In case of stationary sinusoidal signals both logarithmic and linear averaging has the
same results.
Lin ← Average Mode
Activates linear averaging. Linear averaging means that the power level values are
converted into linear units prior to averaging. After the averaging, the data is converted
back into its original unit.
This softkey takes effect if the grid is set to a linear scale (see "Range Linear" softkey,
"Range Linear %" on page 318). In this case, the averaging is done in two ways
(depending on the set unit – see "Unit" softkey):
●
The unit is set to either W or dBm: the data is converted into W prior to averaging,
i.e. averaging is done in W.
●
The unit is set to either V, A, dBmV, dBµV, dBµA or dBpW: the data is converted
into V prior to averaging, i.e. averaging is done in V.
Remote command:
SENS:AVER1:TYPE LIN
, see
[SENSe:]AVERage<n>:TYPE
on page 852
Log ← Average Mode
Activates logarithmic averaging.
Analysis