R&S FSMR, Руководство по эксплуатации, Страница: 221 / 955

R&S FSMR Analyzer - Bandwidths and Sweep Time
1166.3363.12 4.8-5 E-1
SWEEPTIME
AUTO
The SWEEPTIME AUTO softkey couples the sweep time to the span, video
bandwidth (VBW) and resolution bandwidth (RBW) . The sweep time is
automatically adjusted on any change in span, resolution bandwidth or video
bandwidth.
The softkey is only available in the frequency domain (span >0 Hz). It is
blanked in the time domain.
The R&S FSMR always selects the shortest sweep time possible without
falsifying the signal. The maximum level error compared to using a longer
sweep time is < 0.1 dB. If additional bandwidth and level errors are to be
avoided, the sweep time is to be set to three times the time offered in coupled
mode.
IEC/IEEE-bus command:
SWE:TIME:AUTO ON
COUPLING
RATIO
RBW / VBW
PULSE [.1]
RBW / VBW
SINE [1/3]
RBW / VBW
NOISE [10]
SPAN / RBW
AUTO [50]
RBW / VBW
MANUAL
SPAN / RBW
MANUAL
The COUPLING RATIO softkey opens a sub menu for selection
of the coupling ratios.
When the default setting is active, i.e. the
COUPLING RATIO
softkey is deactivated (not highlighted), the ratio span/resolution
bandwidth (SPAN/RBW) is 50 (this corresponds to SPAN / RBW
AUTO [50]) and the ratio resolution bandwidth/video bandwidth
(RBW/VBW) is 0.33 (this corresponds to RBW / VBW SINE
[1/3]).
If the ratio RBW/VBW or SPAN/RBW is different from the
default setting, the
COUPLING RATIO softkey is highlighted.
The softkeys RBW/VBW... are selection keys. Only one softkey
can be enabled at any one time. The softkeys are only effective
for the
VBW AUTO selection in the main menu.
The softkeys SPAN/RBW... are also selection keys. They are
only effective for the
RBW AUTO selection in the main menu.
RBW / VBW
SINE [1/3]
The RBW/VBW SINE [1/3] softkey sets the following coupling
ratio:
video bandwidth = 3 x resolution bandwidth.
This is the default setting for the coupling ratio resolution
bandwidth/video bandwidth.
This is the coupling ratio recommended if sinusoidal signals are
to be measured.
IEC/IEEE-bus command
SENS:BAND:VID:RAT 3
This setting is only effective for the VBW AUTO selection in the
main menu.