Rohde & Schwarz R&S FSP Series, Руководство по эксплуатации

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Operating Manual 1164.4556.12 - 06 4.31
R&S FSP Instrument Functions
Analyzer Mode
For this purpose, the R&S FSP uses a level detector at the second intermediate fre-
quency. The detector threshold can be selected in a range between –30 dBm and -
10 dBm at the input mixer. The resulting trigger level at the RF input is calculated via
the following formula:
The bandwidth at the intermediate frequency is 10 MHz. The R&S FSP is triggered
as soon as the trigger threshold is exceeded within a 5 MHz range around the
selected frequency (= start frequency in the frequency sweep).
Thus, the measurement of spurious emissions, e.g. for pulsed carriers, is possible
even when the carrier lies outside the selected frequency span.
Remote command:
TRIG:SOUR IFP
SWE:EGAT:SOUR IFP
RF POWER
For details see section “TV and RF Trigger – Option R&S FSP-B6” on page 4.209 .
TRIGGER
OFFSET The TRIGGER OFFSET softkey activates the window for entering the time offset
between the trigger signal and the start of the sweep.
Triggering is delayed by the entered time with respect to the trigger signal (time
entered > 0) or is started earlier (time entered < 0). The time may be entered in mul-
tiples of 125 ns in the range -100 s to 100 s (default 0 s).
As a common input signal is used for both trigger and gate when selecting EXTERN
and IF POWER, changes to the gate delay will affect the trigger delay (TRIGGER
OFFSET) as well.
Remote command:
TRIG:HOLD 10US
POLARITY
(POS NEG) The POLARITY (POS NEG) softkey selects the polarity of the trigger source.
The sweep starts after a positive or negative edge of the trigger signal. The selected
setting is highlighted.
The selection is valid for all trigger modes with the exception of FREE RUN ; in the
gate mode, it also applies to the gate polarity.
The default setting is POLARITY POS.
Remote command:
TRIG:SLOP POS
By using a gate in sweep mode and stopping the measurement while the gate signal
is inactive, the spectrum for pulsed RF carriers can be displayed without the super-
position of frequency components generated during switching. Similarly, the spec-
trum can also be examined for an inactive carrier. The sweep can be controlled by
an external gate or by the internal power trigger.
MixerLevel
min
RFAtt PreampGain – + InputSignal MixerLevel
max
RFAtt PreampGain – +
≤ ≤
A negative offset (pretrigger) can be set in the time domain only (SPAN = 0 Hz)
provided GATED TRIGGER is not active in that domain.
The maximum allowed range and the maximum resolution of the pretrigger is lim-
ited by the set sweep time:
max. range = - 499/500 × sweep time
max. resolution = sweep time/500.
Pretriggering is not possible when the rms or the average detector is activated