Rohde & Schwarz R&S FSP Series, Operating Manual

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Operating Manual 1164.4556.12 - 06 4.287
R&S FSP Instrument Functions
LO/IF ports for external mixers - Option R&S FSP-B21
➢
For frequency-dependent level correction, increase every reference value by
the insertion loss to the same extent.
➢
For this the cable loss can be entered via a transducer table.
Such a table should only contain two reference values (band start and end) for
which a
0
is specified.
8. Functions for signal identification
The spectrum represented in Fig. 4.41 contains the input signal and also a large
number of unwanted mixer products. Two functions are provided by the R&S FSP
to identify real input signals. The implemented methods are described in section
“Signal Identification” on page 4.277 . The AUTO ID function is used in this
example.
➢
Activate the function AUTO ID with
[ FREQUENCY : EXTERNAL MIXER : SIGNAL ID : AUTO ID ] .
To obtain a display with the correct level when using AUTO ID , the tolerance
limit taken as a basis for the use of AUTO ID is to be adapted to the mixer (see
explanations on the
AUTO ID function and “Remarks Concerning Signal
Identification with AUTO ID” on page 4.278 ). The tolerance limit has been set
to 5 dB in this example.
➢
Adapt the tolerance limit with
[
FREQUENCY : EXTERNAL MIXER : SIGNAL ID : AUTO ID THRESHOLD :
{tolerance limit} dB ].
The trace shown in Fig. 4.42 is obtained in which unwanted mixer products are
blanked out.
Fig. 4.42 Output spectrum of the multiplier recorded with an external mixer and AUTO ID
1 A P
C L R W R
A
R B W 3 M H z
S W T 5 0 m s
* V B W 1 M H z
R e f - 2 0 d B m
C e n t e r 5 6 G H z S p a n 8 G H z 8 0 0 M H z /
E X T
- 1 2 0
- 1 1 0
- 1 0 0
- 9 0
- 8 0
- 7 0
- 6 0
- 5 0
- 4 0
- 3 0
- 2 0
1
M a r k e r 1 [ T 1 ]
- 3 5 . 0 8 d B m
5 8 . 0 0 0 0 0 0 0 0 0 G H z