Instrument Function
R&S
®
SMC100A
155
Operating Manual 1411.4060.32 ─ 04
"External"
Selects the external source.
The external modulation signal is input via the PULSE EXT connector.
SCPI command:
Polarity
(External Source only)
Selects the polarity of the modulation signal.
"Normal"
The RF signal is
On
while the level is high at the modulation input.
"Inverse"
The RF level is
Off
if the level is high at the modulation input.
SCPI command:
5.5 LF Generator and LF Output - Mod Gen
5.5.1 LF Generator Overview
An LF generator providing sinusoidal and square signals in the frequency range 0.1 Hz
to 1 MHz is available for the basic unit without additional equipment options.
The LF-Generator is the internal source for the analog modulations AM, FM and PhiM,
and provides the signal also at the LF output (front) of the instrument.
The frequency setting for the LF generator can be made both in the modulation menus
and in the "LF Output" menu. The settings are effective for all modulations using the
internal modulation source.
A change to the frequency of the LF generator automatically has an effect on modulation
if the LF generator is selected as the modulation source (i.e. "Internal" is selected as
"Source").
The LF Sweep mode is activated in the "LF Sweep" dialog (see
, on page 155). "RF frequency" and "RF Level" sweeps are activated in
the respective menus of the RF block.
The internal pulse gnenerator enables the generation of single and double pulse signals.
The generator is activated and configured in the "Pulse Generator" menu of the "Mod
Gen" block or in the "Pulse Modulation" menu of the "Modulation" block ("Pulse Gener-
ator" is selected as "Source").
5.5.2 LF Frequency Sweep
The "LF Frequency Sweep" dialog is used to activate and configure a sweep for the LF
frequency.
LF Generator and LF Output - Mod Gen
