Instrument Function
R&S
®
SMC100A
108
Operating Manual 1411.4060.32 ─ 04
Instruments connected downstream can be taken into consideration when setting the
frequency and level by entering a frequency and/or level offset.
Automatic level control ("ALC") ensures maximum level accuracy.
User-specific lists which contain level correction values for any frequency range ("User
Correction") can be created to, for example, compensate the cable attenuation in a test
assembly setup.
The R&S Signal Generator generates the RF signal in unmodulated or analog form. The
signal generator is equipped therefore with the following sources for analog modulations:
●
an internal LF generator
●
an internal pulse generator
●
the external modulation inputs MOD EXT and PULSE EXT.
An external trigger signal for the analog modulations and the sweeps can be provided at
the INST TRIG input.
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).
5.3.2 RF Frequency Settings
The value of the RF frequency is displayed in the header of the instrument's display
("Freq"). This field provides the direct input of the RF frequency. Alternatively, you can
enter the RF frequency in the "Frequency/Phase" dialog.
Be aware that the displayed RF frequency in the header, and the RF output frequency,
entered in the "Frequency/Phase" dialog can be different, as explained in the following
section.
5.3.2.1
RF Frequency vs. RF Output Frequency
The signal generator offers the possibility, to take additional frequency modifications of
a downstream instrument into consideration, such as an offset set by a mixer, or a multiple
of the frequency by a frequency multiplier. The R&S SMC indicates the resulting fre-
quency, including offset and multiplication factor in the header of the screen. I.e. the
indicated frequency corresponds to the frequency at the output of the downstream instru-
ment. However, the frequency at the RF output of your signal generator always corre-
sponds to the frequency set in the "Frequency/Phase" dialog.
In this dialog, you can also enter the values of the downstream instrument.
A set frequency offset is indicated by the "FREQ OFFSET" status message.
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 dialog) * "Multiplier" factor
(Multiplier in dialog) + "Freq offset" (Offset in dialog)
RF Signal - RF Block
