Rohde & Schwarz SMU200A - RF Frequency Settings

Instrument Function
R&S
®
SMU200A
196Operating Manual 1007.9845.32 ─ 15
In case of two-path instrument, both paths are triggered separately. The BNC connector
INST TRIG is assigned to Path A, and the pin INST TRIG B of the AUX I/O interface is
assigned to Path B.
The input REF IN is used to input an external instrument reference, and the output REF
OUT serves as the output of the reference frequency (internal or external).
The RF signals in the case of two-path instruments are generated independently of each
other. Both RF paths are, however, synchronized to the same reference frequency (inter-
nal or external).
5.5.2 RF Frequency Settings
The value of the RF frequency is displayed in the frequency field ("Freq") in the header
of the instrument's display and the simplest way to set the RF frequency is to set it directly
in this field.
Be aware, that there is a difference between the RF frequency displayed in the header
and the RF output frequency set in the "Frequency/Phase" menu of the "RF/A Mod"
function.
5.5.2.1 RF frequency vs. RF output frequency
The frequency entered and displayed in the frequency field in the header of the display
takes any set frequency offset into consideration, e.g. an offset set for a downstream
instrument. This means that with a frequency offset the frequency displayed in the header
does not correspond to the frequency at the RF output, but rather to the frequency at the
output of the downstream instrument. A set frequency offset is indicated by the "FREQ
OFFSET" status message.
This instrument t allows the desired frequency at the output of a downstreamo be entered
in the frequency field. The R&S Signal Generator changes the RF output frequency
according to the entered offset.
However, the frequency entered and displayed in the "Frequency/Phase" dialog of the
"RF" function block always corresponds to the RF output frequency. Any frequency offset
is not taken into consideration.
The frequency offset is entered in the "Frequency/Phase" dialog. Here it is also possible
to set the frequency without taking the offset into consideration, to set the step width for
the frequency entry using the rotary knob, and to set the phase for the RF output signal.
The correlation between the RF frequency, the RF output frequency and the frequency
offset is as follows:
"Freq" (in header) = "RF output frequency" (Frequency in menu) + "Freq offset" (Offset
in menu)
RF Signal and Analog Modulations - RF Block