Rohde & Schwarz SMF-B1, Operating Manual

Page: 289 / 653

Instrument Function
R&S
®
SMF100A
274 Operating Manual 1167.2319.02 ─ 12
Remote command:
[:SOURce<hw>]:CHIRp:TRIGger:EXTernal:GATE:POLarity
on page 451
External Impedance - Chirp Modulation
Selects the input impedance for the external trigger and gate signal input (10 kOhm or
50 Ohms).
Remote command:
[:SOURce<hw>]:CHIRp:TRIGger:EXTernal:IMPedance
on page 451
5.6 Modulation Generator, Pulse Generator and LF Out-
put
5.6.1 LF Gen./Noise
The "LF Gen./Noise" block provides two internal LF generators which can be used as
internal modulation sources for analog modulations (amplitude modulation, frequency
modulation, phase modulation) and a noise generator. The LF/Noise generators can
also be used as the signal source for the LF output at the front of the instrument.
The internal LF/Noise generators require option R&S SMF-B20.
Both LF generators providing sinusoidal signals in the frequency range 0.1 Hz to 10
MHz with selectable signal shapes e.g. sine waves, triangle/ pulse/ trapezoid signals.
The LF frequency settings for the LF generator can be made in the LF Gen./Noise
menu, LF Output menu, and analog modulation menus.
A change to the frequency of the LF generator automatically has an effect on modula-
tion if the LF generator is selected as the modulation source. For example, a change to
the frequency of the first LF generator automatically has an effect on the amplitude
modulation if the first LF generator is selected as the AM modulation source (i.e. LF
Generator 1 is selected as Source). On the other hand, changing the frequency in the
Amplitude Modulation menu has an effect to the LF output signal.
The LF frequency sweep mode is activated in the LF Frequency Sweep menu. The LF
level sweep is activated in the LF Level Sweep menu of the "LF Output" block.
The noise generator supplies noise with selectable bandwidth and level distribution.
The LF frequency sweep mode is activated in the "LF Frequency Sweep" dialog of the
"LF Gen./Noise" block (see
Chapter 5.6.1.3, "LF Frequency Sweep" , on page 278).
The LF level sweep is activated in the "LF Level Sweep" dialog of the "LF Output"
block (see
Chapter 5.6.2.2, "LF Level Sweep" , on page 288).
Modulation Generator, Pulse Generator and LF Output