R&S FSW Series, Руководство пользователя

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Common Measurement Settings
R&S
®
FSW
390 User Manual 1173.9411.02 ─ 43
●
Manual coupling : a single frequency is defined
●
Automatic coupling : a series of frequencies is defined (one for each sweep
point), based on the current frequency at the RF input of the R&S FSW; the RF fre-
quency range covers the currently defined span of the R&S FSW (unless limited by
the range of the signal generator)
Automatic coupling
If automatic coupling is used, the output frequency of the generator (source frequency)
is calculated as follows:
Offset Analyzer Generator
F
ator Deno
Numerator
F F
  
min
Equation 8-1: Output frequency of the generator
Where:
F
Generator
= output frequency of the generator
F
Analyzer
= current frequency at the RF input of the R&S FSW
Numerator = multiplication factor for F
Analyzer
Denominator = division factor for F
Analyzer
F
Offset
= frequency offset for F
Analyzer
, for example for frequency-converting measure-
ments or harmonics measurements
The value range for the offset depends on the selected generator. The default setting is
0
Hz. Offsets other than 0 Hz are indicated by the "FRQ" label in the channel bar (see
also "Displayed Information and Errors" on page 392).
Swept frequency range
The F
Analyzer
values for the calibration sweep start with the start frequency and end with
the stop frequency defined in the "Frequency" settings of the R&S FSW. The resulting
output frequencies ( Result Frequency Start and Result Frequency Stop ) are displayed
in "External Generator" > "Measurement Configuration" for reference.
If the resulting frequency range exceeds the allowed ranges of the signal generator, an
error message is displayed (see
"Displayed Information and Errors" on page 392) and
the Result Frequency Start and Result Frequency Stop values are corrected to comply
with the range limits.
The calibration sweep nevertheless covers the entire span defined by the R&S FSW;
however, no input is received from the generator outside the generator's defined limits.
TTL synchronization
Some Rohde & Schwarz signal generators support TTL synchronization when connec-
ted via GPIB. The TTL interface is included in the AUX control connector of the Exter-
nal Generator Control option.
Data Input and Output