R&S SMB100A Operating Manual page 215

®
R&S SMB100A
"External"
"Intern + Extern"
Remote command:
[:SOURce<hw>]:AM:SOURce
AM Type
Selects between linear or exponential (logarithmic) amplitude modulation, if you work
with an instrument that is equipped with a 12 GHz, or higher frequency option.
Remote command:
[:SOURce<hw>]:AM:TYPE
AM Depth
Sets the modulation depth in percent.
Note: With two-tone modulation, observe that the set modulation depth applies to both
signals and the sum modulation depth is determined by doubling the set modulation
depth. This results in overmodulation if the maximal value for modulation depth is
exceeded (see data sheet).
For instruments with frequency option 12 GHz or higher, you can additionally select
AM Type
mic).
Modulation is possible both, upwards and downwards. Accordingly, the dynamic range
extends for instruments without attenuator from minimum to maximum level. For instru-
ments with attenuator, the dynamic range corresponds to the
these are downwards about 20 dB, and upwards about 5 dB, that means in total about
25 dB around the set level.
Effects of positive/negative modulation depth:
●
AM Source Int
–
–
●
AM Source Ext
–
–
–
–
Remote command:
[:SOURce<hw>]:AM:DEPTh:LINear
[:SOURce<hw>]:AM:DEPTh:EXPonential
LF Gen Freq
Sets the frequency of the LF generator.
This setting affects all analog modulations which use the LF generator as the internal
modulation source.
Operating Manual 1407.0806.32 ─ 21
Uses an externally applied modulation signal.
The external signal is input via the MOD EXT connector.
Uses both, the internal and externally applied modulation signal, for
example to perform two-tone AM.
Note: This setting applies to linear AM, see
ments with high frequency options)"
on page 328
Exponential. In this case, the generator sets modulation depth in dB (logarith-
positive depth -> downwards modulation
negative depth -> upwards modulation
positive depth and negative external voltage -> downwards modulation
positive depth and positive external voltage -> upwards modulation
negative depth and negative external voltage -> upwards modulation
negative depth and positive external voltage -> downwards modulation
on page 199.
on page 327
on page 326
on page 325
Instrument Function
Modulation
"Exponential AM (Instru-
Fixed Range (PEP) In;
200