R&S FSW Series, Руководство пользователя

Страница: 455 / 1450

Common Measurement Settings
R&S
®
FSW
455 User Manual 1173.9411.02 ─ 43
When you switch off electronic attenuation, the RF attenuation is automatically set to
the same mode (auto/manual) as the electronic attenuation was set to. Thus, the RF
attenuation can be set to automatic mode, and the full attenuation is provided by the
mechanical attenuator, if possible.
The electronic attenuation can be varied in 1
dB steps. If the electronic attenuation is
on, the mechanical attenuation can be varied in 5 dB steps. Other entries are rounded
to the next lower integer value.
For the R&S FSW85, the mechanical attenuation can be varied only in 10 dB steps.
If the defined reference level cannot be set for the given attenuation, the reference
level is adjusted accordingly and the warning "limit reached" is displayed in the status
bar.
Remote command:
INPut<ip>:EATT:STATe
on page 1044
INPut<ip>:EATT:AUTO
on page 1043
INPut<ip>:EATT
on page 1043
Input Settings
Some input settings affect the measured amplitude of the signal, as well.
The parameters "Input Coupling" and "Impedance" are identical to those in the "Input"
settings.
See Chapter 8.2.2, "Input Source Settings" , on page 366.
Preamplifier ← Input Settings
If the (optional) internal preamplifier hardware is installed, a preamplifier can be activa-
ted for the RF input signal.
You can use a preamplifier to analyze signals from DUTs with low output power.
Note that if an optional external preamplifier is activated, the internal preamplifier is
automatically disabled, and vice versa.
For R&S FSW8, 13, and 26 models, the following settings are available:
"Off" Deactivates the preamplifier.
"15 dB" The RF input signal is amplified by about 15 dB.
"30 dB" The RF input signal is amplified by about 30 dB.
For R&S FSW43 or higher models, the input signal is amplified by 30 dB if the pream-
plifier is activated.
Remote command:
INPut<ip>:GAIN:STATe
on page 1045
INPut<ip>:GAIN[:VALue]
on page 1046
Ext. PA Correction ← Input Settings
This function is only available if an external preamplifier is connected to the R&S FSW,
and only for frequencies above 1 GHz. For details on connection, see the preamplifier's
documentation.
Using an external preamplifier, you can measure signals from devices under test with
low output power, using measurement devices which feature a low sensitivity and do
not have a built-in RF preamplifier.
Amplitude and Vertical Axis Configuration