Local Oscillator (Lo) Coupling Settings - R&S SGT100A User Manual

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R&S SGT100A
If two signal generators are coupled via their 10 MHz reference, they are generating
exactly the same frequency but only in the long-term perspective. Having a closer look
into the instantaneous differential phase ("delta phase") of these two RF signals, this is
quite instable due to:
●
Phase noise of the two synthesizers
●
"Weak" coupling at 10 MHz and a long synthesis chain up to the RF domain
●
Temperature differences which cause slightly different phase drifts for the different
synthesizers
Most critical for a stable delta phase is the thermal RF phase fluctuation between multi-
ple RF synthesizers. These fluctuations can be minimized by using a common synthe-
sizer (common local oscillator (LO) signal) for all RF carriers.
7.7.4.2

Local Oscillator (LO) Coupling Settings

The LO coupling settings are provided in the "Frequency/Phase" dialog.
► To access this dialog, select "SGMA-GUI > Instrument Name > Frequency/Phase >
Local Oscillator (LO) Coupling".
Source
Selects the source of the local oscillator signal.
"Int"
User Manual 1176.8674.02 ─ 07
The instrument uses the built-in local oscillator.
Signal Generator Settings
RF Settings
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