Configuring the Signal in the RF Domain
R&S
®
SMW200A
453User Manual 1175.6632.02 ─ 16
Adjust LO Level at Current Frequency
Adjusts the level of the oscillator signal to optimum, if an external LO signal is applied,
see To adjust the LO level to current frequency.
The function is enabled in the following cases:
●
An external "LO Coupling Mode" is selected.
●
"Out State" is on ("B On" or "On").
Note: If your test setup consists of several cascaded Rohde & Schwarz instruments,
always use an external oscillator signal and start the LO level adjustment with the first
instrument. Continue in the order up to the last.
Remote command:
:CALibration<hw>:LOSCillator:COUPling:LOCal? on page 793
7.5.4 How to Adjust the LO Level, Find the Connectors and Configure
Cascaded Instruments
This section describes how you can find out the location of the LO signal connectors
(LO IN/OUT), and tips on adjusting the LO signal level when using an external signal.
You can also find instructions for configuring the LO signals of several disconnected
signal generators.
To adjust the LO level to current frequency
If you are working with an external LO signal, we recommend that you adjust the inter-
nal LO level to the optimum value.
To adjust the internal signal level, proceed as follows:
1. In the "Reference Freq. / LO Coupling" tab, section "Local Oscillator (LO) Cou-
pling", select one of the following:
● "Mode" > "A External & B Internal"
● "Mode" > "A External & A-> B Coupled"
● "Mode" > "External" if you are working with a one path instrument
● "Mode" > "A External & B RF Off"
● "Mode" > "A RF OFF & B External"
2. Apply the oscillator signal, with a level of 10 dBm ±3 dB at the corresponding LO IN
connector (see Chapter 11.2.4, "RF Connectors Settings", on page 667).
3. Check if the external oscillator signal has the required frequency, as shown in the
dialog under "LO OUT Frequency".
4. Set "Out State > B On".
5. Execute "Adjust LO Level Current Frequency".
The R&S SMW automatically adjusts the internal LO signal level at the I/Q modula-
tor and the LO OUT connector.
Local Oscillator Coupling
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