Rohde & Schwarz R&S FSP Series, Operating Manual

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R&S FSP Instrument Functions
Analyzer Mode
4.116 Operating Manual 1164.4556.12 - 06
CHANNEL
BANDWIDTH
The CHANNEL BANDWIDTH softkey opens a window for selecting the measure-
ment channel bandwidth.
The default setting is 14 kHz.
The specified channel bandwidth allows the optimal setting of the measurement
parameters of the R&S FSP using
ADJUST SETTINGS .
Remote command:
SENS:POW:ACH:BWID 14kHz
ADJUST
SETTINGS
The ADJUST SETTINGS softkey adapts the span to the channel bandwidth
selected.
For the carrier/noise ratio measurement, the span is set to:
4 × channel ban measurement margin
The adjustment is performed once; if necessary, the setting can be changed later
on.
Remote command:
SENS:POW:ACH:PRES CN | CN0
4.5.13.6 Measurement of the AM Modulation Depth
MODULATION
DEPTH
The MODULATION DEPTH softkey switches on the measurement of the AM modu-
lation depth. An AM-modulated carrier is required on the screen for ensuring correct
operation.
The level value of MARKER 1 is taken as the carrier level. When this function is acti-
vated, MARKER 2 and MARKER 3 are automatically set symmetrically to the carrier
on the adjacent peak values of the trace as delta markers and MARKER 2 is acti-
vated for the entry.
When the position of MARKER 2 (delta) is changed, MARKER 3 (delta) is moved
symmetrically with respect to the reference marker (MARKER 1).
If the data entry is activated for MARKER 3 ( MARKER 1 2 3 4 softkey), the latter can
be moved for fine adjustment irrespective of MARKER 2.
The R&S FSP calculates the power at the marker positions from the measured lev-
els. The AM modulation depth is calculated from the ratio between the power values
at the reference marker and at the delta markers. When the powers of the two AM
side bands are unequal, the mean value of the two power values is used for AM
modulation depth calculation.