Configuring the Signal in the RF Domain
R&S
®
SMW200A
456User Manual 1175.6632.02 ─ 16
4. Configure Signal Generator 3
a) Set "Freq > 5 GHz".
b) Select "RF > Ext. Ref / LO Coupling > Mode > External".
c) Set "Out State > Off".
d) If the attenuation between the interconnection "LO OUT" and "LO IN" is greater
than 1 dB at the oscillator frequency, we recommend that you perform level
adjustment:
● Check if the "Adjust LO Level Current Frequency" procedure of the previ-
ous instrument is completed.
● Execute "Adjust LO Level Current Frequency".
The signal generator automatically adjusts the internal LO signal level at the
I/Q modulator and LO OUT connector.
All instruments generate the RF signals in phase, as they use the same oscillator
signal looped through all instruments.
Example: Generating a beamformed signal with two Rohde & Schwarz Signal
Generators
This example shows a test setup with two generators, each equipped with two paths,
like for example the R&S SMW or the R&S SMU200A.
Figure 7-7: Set up of LO coupling with two Rohde
&
Schwarz Signal Generators
Generator 1 = "A Internal & A->B Coupled"; "LO OUT > On"
Generator 2 = "A External & A->B Coupled"; "LO OUT > Off"
The signal generator 1 uses the internal oscillator signal of path A also in path B. The
signal generator 2 receives the LO signal from the first instrument and assigns it to
both paths. The frequency is assumed to be 2 GHz.
Depending on the required RF frequency, your instrument may not be adequately
equipped in one of the paths. If so, you can adjust the LO coupling mode accordingly
to use the LO signal from the other path. Proceed as described under Configure Signal
Generator 2 in the example "Cascading three Rohde & Schwarz Signal Generators".
Local Oscillator Coupling
To Next Page
Loading...
