Instrument Function
R&S
®
SMU200A
322Operating Manual 1007.9845.32 ─ 15
(see data sheet). Apart from the memory size, however, the options offer the same func-
tionality, either one can be installed.
In addition, the appropriate option is required for the digital standards. These options are
specified in the description of the respective standard.
The minimum equipment for a two-path instrument is a second R&S SMU-B9/B10/B11
option. This can be used simultaneously on the second path to generate a modulation
signal which can either be routed via path A or added to the signal on path A with a
frequency offset that can be set. In the case of a fully two-path layout, path B can be
operated as a second signal generator independently of path A (see also data sheet).
If the appropriate options are fitted, externally supplied real-time baseband signals can
be added to the internally generated signals.
In the subsequent signal route the baseband signals can be frequency-shifted, faded,
detuned or loaded with noise (see chapter 5.9, "External Baseband Signal - Baseband
Input", on page 436, chapter 5.7, "Impairment of Digital I/Q Signal and Noise Generator
- AWGN/IMP Block", on page 288 and the description "Fading Simulator").
5.8.1 Working with the Baseband Signal
In the case of two-path instruments, signal routing, frequency offset and path gain defi-
nition are defined at the topmost menu level in the "Baseband" block or by using the
MENU button under "Baseband".
The upper part of the "Baseband" dialog is used for selecting digital standards, digital
modulation and waveform generation. These menus are described in the respective
chapters relating to the modulation systems.
The lower part of the "Baseband" dialog can be used to define a frequency offset a path
gain, a phase offset, and the signal routing for two-path instruments.
Frequency Offset
Enters the frequency offset for the baseband signal.
The frequency offset shifts the baseband frequency interval and provides a quick way to
shift the used frequency band in the RF frequency section without modifying the RF set-
tings.
Wenn a frequency offset is defined, an icon is displayed in the signal flow right to the
baseband block.
Note: For sample rates of exactly 100 MHz (Mode Digital Input (Native100MHz)) it is
not possible to enter a frequency offset. The digital signal is fed into the signal path directly
and not routed to the resampler where the frequency offset takes place. This type of entry
is also prohibited if the noise generator ("AWGN" block) is on.
Baseband Signal - Baseband Block
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