Rohde & Schwarz SMM100A, Руководство пользователя

Страница: 317 / 1088

Configuring the RF signal
R&S
®
SMM100A
317 User Manual 1179.1341.02 ─ 05
This section gives an overview of the possible test setups and the related settings. The
following situations are considered:
●
External reference source is not available or the built-in reference oscillator is of
better quality than the external source
(see
"Distributing the internal 10 MHz reference signal to further instruments"
on page 317)
●
Clean external reference source with quality exceeding the quality of the built-in
reference oscillator
(see
"Using external reference source" on page 318)
●
Interfered or noisy external reference signal
(see "Deriving 10 MHz from the external reference frequency" on page 319)
●
1 GHz reference coupling for phase coherence of the RF signals with enhanced
long-term phase stability
(see
"Sharing the 1 GHz reference frequency to obtain phase-coherent signals"
on page 318)
Connectors overview
Use the "Show Connector" function to indicate the connector on the front/real panel:
●
"Ref In/Ref Out" on page 43
●
1GHz "Ref In/Ref Out" on page 43
●
"EFC" on page 44
Distributing the internal 10 MHz reference signal to further instruments
The internal reference oscillator provides the reference frequency:
●
Internal f
ref
= 10 MHz (10 MHz at connector Ref Out)
●
Source = "Internal"
●
Reference Output/1 GHz Reference Output = "10 MHz"
Figure 7-3: Synchronizing instruments using the internal 10 MHz reference signal of the
R&S SMM100A
EFC = External frequency control
EFC,Ref In,Ref Out = Connectors
In phase noise measurement systems, for example, you can also use the EFC (exter-
nal frequency control) function and shift the frequency. EFC is a function that trans-
forms an external tuning voltage into frequency shift, where the value range of the
resulting frequency is a technical characteristic listed in the data sheet. See the data
sheet also for information on the sensitivity, input voltage range, impedance and maxi-
mum bandwidth for external tuning signal.
Reference oscillator