R&S ESU Series Operating Manual page 197

R&S ESU
EXCLUDE LO The EXCLUDE LO softkey limits the frequency range for the marker search func-
tions or disables the limit.
activated
deactivated
Remote command:
PEAK The PEAK EXCURSION softkey enables – for level measurements – the entry of a
EXCURSION minimum level value by which a signal must rise or fall so that it will be identified as
a maximum or a minimum by the NEXT PEAK and NEXT MIN search functions.
Valid entries are from 0 dB to 80 dB; the resolution is 0.1 dB.
Remote command:
The default setting for the peak excursion is 6 dB. This value is sufficient for the
NEXT PEAK and NEXT MIN functions since, in this mode, the next lower maximum
or next higher minimum will always be detected.
If NEXT PEAK LEFT or NEXT PEAK RIGHT is selected, these functions search for
the next relative maximum left or right of the current marker position irrespective of
the current signal amplitude. Relative maximum is understood to mean a decrease
of the signal amplitude by a defined value – i.e. the peak excursion – right and left of
the amplitude peak.
The 6 dB level change set as a default value may be attained already by the inher-
ent noise of the instrument. In such a case, the R&S ESU would identify noise peaks
as maxima or minima. The value entered for the PEAK EXCURSION should there-
fore be higher than the difference between the highest and the lowest value mea-
sured for the displayed inherent noise.
The following example illustrates the effect of different settings of the PEAK
EXCURSION.
4.166
Because of the feed through of the first local oscillator to the first
intermediate frequency at the input mixer, the LO is represented as a
signal at 0 Hz. To avoid the marker jumping to the LO at 0 Hz with the
peak function when setting the display range, this frequency is
excluded. The minimum frequency to which the marker jumps, is ≥ 6
× resolution bandwidth (RBW).
No restriction to the search range. The frequency 0 Hz is included in
the marker search functions.
CALC:MARK:LOEX ON
CALC:MARK:PEXC 10dB
Instrument Functions
Analyzer Mode
Operating Manual 1302.6163.12 - 03