R&S SMJ100A, Operating Manual

Page: 269 / 874

Instrument Function
R&S
®
SMJ100A
253 Operating Manual 1403.7458.32 ─ 14
Remote command:
[:SOURce<hw>]:PULM:SOURce
on page 773
LFGen Frequency - Pulse Modulation
Sets the repetition frequency of the internal signal.
This setting affects all analog modulations which use the LF generator as the internal
modulation source.
Remote command:
[:SOURce]:LFOutput:FREQuency
on page 738
External Input Impedance
(Source External only)
Sets the impedance for the external modulation signal, applied at the EXT MOD con-
nector.
You can select 50 Ohm or high (>100 kOhm).
Note: The selection of 50 Ohm to ground requires that your instrument is equipped
with the extended synthesis assembly (SynEx).
This setting affects all analog modulations which use the external modulation signal.
Remote command:
[:SOURce<hw>]:INPut:MODext:IMPedance
on page 721
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.
"Inverted" The RF signal is Off while the level is high at the modulation input.
Remote command:
[:SOURce<hw>]:PULM:POLarity
on page 773
5.5.12 Modulation Generator and LF Output
5.5.12.1 Overview of LF Generator
The internal modulation generator of the instrument provides a sinusodial LF modula-
tion signal without additional equipment options. The corresponding key data, as for
example the frequency range, is specified under "Modulation sources" in the data
sheet.
You can use the internal LF signal as modulation signal source for the analog modula-
tions, as for example the amplitude modulation. The signal applies to all modulations
which are using the internal modulation signal. Therefore, any modification of the LF
signal impacts all currently active modulations immediately.
RF Signal and Analog Modulations - RF Block