Rohde & Schwarz SMM100A, User Manual

Page: 260 / 1088

Configuring the internal baseband source
R&S
®
SMM100A
260 User Manual 1179.1341.02 ─ 05
The block diagram shows an icon
Δf
on the signal path to indicate an applied fre-
quency offset.
Settings:
Frequency Offset .........................................................................................................260
Phase Offset ................................................................................................................260
Frequency Offset
Enters the frequency offset for the internal or external baseband signal and shifts the
useful baseband signal in the center frequency.
Use function, for example, to shift the baseband signal relative to the AWGN signal.
See:
●
Chapter 4.12.1.1, "Impact of the frequency offset" , on page 257 for detailed infor-
mation on the calculation of the frequency offset value range
●
Chapter 4.12.3, "How to improve signal characteristics by shifting the baseband
signal"
, on page 260
Remote command:
[:SOURce<hw>]:BB:FOFFset
on page 768
[:SOURce<hw>]:BBIN:FOFFset
on page 768
Phase Offset
Enters the phase offset for the baseband signal (see Chapter 4.12.1.2, "Impact of the
phase offset" , on page 259).
The phase offset affects the signal on the "Baseband block" output.
Use this parameter, for example, to change the start phase of the baseband signal.
Remote command:
[:SOURce<hw>]:BB:POFFset
on page 768
[:SOURce<hw>]:BBIN:POFFset
on page 768
4.12.3 How to improve signal characteristics by shifting the baseband sig-
nal
Shifting of the generated baseband signal is useful in the following cases:
●
You analyze the generated signal with a signal analyzer and the displayed signal
spectrum indicates a carrier leakage (a signal drop) at the current RF frequency.
Shifting and boosting the baseband signal