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Common Measurement Settings
R&S
®
ESW
156
User Manual 1177.6298.02 ─ 08
Coupling the Frequencies
Frequency coupling means that the generator frequency and the frequency of the
R&S
ESW are the same.
●
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
ESW; the RF fre-
quency range covers the currently defined span of the R&S
ESW (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 10-1: 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
ESW
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"
Swept frequency range
The F
Analyzer
values for a swept measurement start with the start frequency and end
with the stop frequency defined in the "Frequency" settings of the R&S
ESW. The
resulting output frequencies (
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"
values are corrected to comply
with the range 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