4-3
Coupling
Frequency and level coupling
Many measurements are made where it is convenient if the carrier frequencies and RF levels of
signal sources are automatically related to each other. The coupling setup facility allows two
signal sources to be coupled together in frequency and/or level. The frequencies can be coupled
with a defined offset value (for example 10.7 MHz), and can be harmonically related. The
harmonic relationship is useful where a harmonic sampling gate or divider is being tested. RF
levels can be entered in dB. Coupling factors of the B source are always set relative to the A
source.
The frequency coupling is entered in the form:
Frequency (B) = frequency (A)
×
N
+
offset frequency
OR
Frequency (B) = frequency (A)/N
+
offset frequency
where N is an integer between 1 and 9
The B source can be coupled only by entering its value relative to the A source. Offsets can have
either positive or negative values.
Whenever a coupling factor has been set the signal generator display clearly identifies the presence
of coupling factors in the frequency or level display fields by displaying an icon of the form
ð
B
under the frequency/level units to indicate which source that parameter is currently coupled to.
Coupling selection
To set the coupling factors proceed as follows:
(1) On
the
Setup Menu
press the
[Coupling Setup]
key to display the Frequency and Level
Coupling menu (see Fig. 4-3 below). The screen is split horizontally into two, with the upper
part displaying the frequency coupling parameters and the lower part displaying the level
coupling parameters.
Fig. 4-3 Frequency and level coupling menu
