Configuring the RF signal
R&S
®
SMM100A
309
User Manual 1179.1341.02 ─ 05
To configure LO coupling with cascaded instruments to achieve phase coher-
ence
The LO Coupling function can be used to generate beamforming signals.
The test setups in the following examples represent possible applications and provide
information about the coupling modes set in the signal generators. For the configura-
tion via remote control, see the examples in
Chapter 13.16.6, "SOURce:FREQuency
The first test setup example represents all variants of the coupling modes, and
describes step-by-step how to configure each of the Rohde
&
Schwarz signal genera-
tors. The following examples show further conceivable test setups. To configure these
test setups, proceed similarly as shown in the first example.
Example: Cascading three Rohde
&
Schwarz Signal Generators
Figure 7-2: Set up of LO coupling with three Rohde
&
Schwarz Signal Generators
Generator 1 = "Internal"; "LO Out > Off"
Generator 2 = "A External & A->B Coupled"; "LO Out > On"
Generator 3 = "External"; "LO Out > Off"
A frequency of 5
GHz is assumed.
●
Signal Generator 1 is a one-path instrument, for example R&S
SMM100A and uses
its internal oscillator signal.
●
Signal Generator 2 is a two-paths instrument, for example a R&S
SMW200A. It
receives the LO signal from the first instrument and assigns it to both paths.
●
Signal Generator 3 is a one-path instrument, for example R&S
SMM100A,
R&S
SGT100A, or R&S
SMBV100A. It receives the LO signal from the second
instrument.
To configure the application, proceed as follows:
1. Connect the first signal generator Ref Out with LO In of the second instrument, and
similarly the LO Out of the second signal generator with LO In of the third.
2. Configure
Signal Generator 1.
Select "Freq = 5
GHz".
a) Select "RF > LO Coupling > Mode > Internal".
b) Set "Out State > On".
3. Configure
Signal Generator 2.
a) Set "Freq => 5
GHz".
Local oscillator coupling