Rohde & Schwarz 1164.4391.03, Service Manual

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Instrument Design and Function Description R&S FSP
1164.4556.82 3.6 E-1
Reference Frequency 10 MHz - IF Filter Module
The reference frequency is generated by a TCXO, and the frequency is adjustable by means of a D/A
converter. As another choice, an OCXO or an external reference input (REF IN) can be switched on. In
any case, the active reference will be routed to the reference output.
4
1
32 MHz, 0dBm
to Detector
CAL
Generator
128MHz, 0dBm
to Detector
TCXO
Reference
Adjust
Selftest
Selftest
Selftest
X141
X135
X136
128MHz, 0dBm
to Options
128MHz Cal Signal
0 / -30 dBm
to RF-ATTen
X142
128MHz, 0dBm
from Frontend
X134
10MHz, 0dBm
to Frontend
X133
10MHz, 0dBm
to Rear Panel
REF OUT
X143
10MHz
from Rear Panel
REF IN
X144
10MHz, 0dBm
from OCXO Option
X145
Reference
Adjust
Fig. 3-5 Reference frequency
Reference Frequency 128 MHz - IF Filter Module
This reference is generated on the frontend and is synchronized to the 10 MHz reference.
The signal from the frontend (128 MHz reference) is decoupled and distributed to the detector and to
other options.
The 128 MHz calibration signal is generated with automatic level control. The level is switchable
between 0 dBm and -30 dBm. The level is adjustable with a D/A converter.
A 4:1 divider generates the 32 MHz clock for the detector board (A/D converter).
OCXO Reference (Option R&S FSP-B4)
The R&S FSP contains the option R&S FSP-B4, an oven-controlled crystal oscillator (OCXO). This
OCXO generates a 10 MHz signal, which is routed to the IF filter board and used as a reference signal.
WCDMA Demodulation Hardware (Option R&S FSP-B15)
Option R&S FSP-B15 is required for broadband vector analysis. The module is inserted into the line of
the 128 MHz calibration signal between the IF module and the attenuator. A pulse with a frequency of
62.5 kHz is generated from the 128 MHz signal by frequency division. This pulse is used to calibrate the
10 MHz IF filter.