Rohde & Schwarz SMBV100B, Руководство пользователя

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Configuring the RF Signal
R&S
®
SMBV100B
294 User Manual 1178.4460.02 ─ 03
Remote command:
[:SOURce<hw>]:POWer:LIMit[:AMPLitude]
on page 870
Offset
Sets a level offset.
This value represents the level shift of a downstream instrument, like, for example, an
attenuator or an amplifier.
The "Level" value displayed in the status bar is the resulting level, as it is at the output
of the downstream instrument. The level at the R&S
SMBV100B RF output is not
changed.
See "RF frequency and level display with a downstream instrument" on page 288.
Remote command:
[:SOURce<hw>]:POWer[:LEVel][:IMMediate]:OFFSet
on page 874
Digital Attenuation
Attenuates or raises the level of the internal, digitally modulated I/Q baseband signals,
and thus the level of the RF signal accordingly.
The function allows fast level changes of the internal I/Q signals. You can determine an
attenuation value between -3
dB and +80 dB. The instrument calculates the digital
attenuation to the Level
PEP
and the Level
rms
as follows:
Level
PEP(RF output)
= Level
PEP
- Digital Attenuation
Level
rms(RF output)
= Level
rms
- Digital Attenuation
The level range changes accordingly.
Note: The digital attenuation has no effect on the RF output level when you work in
CW mode or with externally applied I/Q signals, i.e. with unmodulated signals.
If the digital attenuation effects the RF level, the R&S
SMBV100B indicates the result-
ing level in the "Status bar". It is also denoted by an icon next to the level indicator.
Note also that several other parameters affect the displayed RF level value.
See
"RF frequency and level display with a downstream instrument" on page 288.
Remote command:
[:SOURce<hw>]:POWer:ATTenuation:DIGital
on page 869
Setting Characteristics
Selects additional quality characteristics to optimize the behavior of the RF signal level
for the corresponding application.
"Auto" Sets the RF output level automatically according to the selected
mode.
In this mode, the instrument provides the highest dynamic range and
fastest setting times, as specified in the data sheet.
The RF signal is shortly blanked when the step attenuator is switch-
ing.
RF Level Settings