Rohde & Schwarz R&S UPP, User Manual

Page: 410 / 938

Instrument Functions
R&S
®
UPP
394 User Manual 1411.1055.32 ─ 10
Fundamental
Used to determine the fundamental frequency.
"Auto" The fundamental frequency is determined (separately for each chan-
nel) by means of internal frequency measurement.
Recommended when using an external signal source
"Value " Fixed fundamental frequency; the value of which must be entered in
the parameter field below
Recommended for signals with a high noise component if an external
generator is used as the signal source
"Gen Track" The fundamental frequency changes with the generator (nominal) fre-
quency. This can be changed by means of manual entry in the Gener-
ator Function panel or owing to a generator frequency sweep. Setting
reliability in the case of signals with a high noise component is thus
improved and measurement speed is increased.
An error message is output if an unsuitable signal function is selected
in the generator (e.g. a multi-tone signal or noise signal).
Recommended when using the internal universal generator.
Remote command:
SENSe[1]:VOLTage:FUNDamental:MODE
on page 760
SENSe[1]:VOLTage:FUNDamental
on page 759
Filter
Two digital filters (user-definable filters or weighting filters) in the measurement path.
The filters used here only affect the residual signal. In other words, the THD+N refer-
ence value is always the RMS signal at the Monitor level, regardless of the filters
selected here.
By contrast, the input filter ("Pre Filter") affects the residual signal and the total RMS
value.
Five measurement scenarios for THD+N, SINAD and noise can thus be distinguished
based on the selected input and function filters:
●
Scenario 1 – Input and function filter off :
Distortion Measurements