Rohde & Schwarz R&S SMU200A, Руководство по обслуживанию

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Instrument Design and Function Description R&S SMU200A
1007.9845.82 3.10 E-6
DAC Board
One or two DAC Board modules are mounted on the DAC Interface motherboard, depending on the
instrument configuration. If only one path is fitted, the DAC A slot (on the right-hand side when viewed
from the front) must be mounted.
The DAC board receives the digital I/Q data from the baseband. This data is transmitted as multiplexed
LVDS data flows with a 100 MHz clock rate and 700 MHz data rate as defined by TIA644. The received
data is then processed further in the FPGA “PRENOI”. In some cases, AWGN (noise) is added and the
delay distortions of the anti-aliasing filters downstream of the converters are compensated. The signal
then reaches the converters for I and Q and finally passes through the anti-aliasing filters.
Baseband Input
This option consists of two modules: BBIN-R (placed at the rear panel) and BBIN-S (placed behind the
Front Module).
BBIN-R (rear)
The BBIN-R enables the digital IQ input on the R&S SMU. It is fitted in slot is X117.
The following functions are provided:
Digital IQ input (see Operating Manual, Chapter 8 'Maintenance and Interfaces')
These input signals are received on the module and sent resynchronized to the BBIN-S.
Generation of a +5 V supply voltage for external instruments.
BBIN-S (front)
The module BBIN-S is installed the slot X111. Vacant slots between the BBIN-S and the next baseband
module (DAC Interface, Fading Simulator, Universal Coder) have to be bridged with the IQ Bridge
module (see above).
The following functions are provided:
Analog I/Q input signals can be digitized (filtering, A/D conversion with R&S SMU system clock rate of
100 MHz) for further baseband processing or directly fed through to the IQOP3 module.