R&S FSH Spectrum Analyzer Mode
Configuring Spectrum Measurements
Operating Manual 1173.6275.12 - 30 107
● Gated Trigger
When the gated trigger is active, a gate signal that is applied to the R&S FSH
trigger input controls the sweep. The R&S FSH starts measuring when the applied
gate signal becomes active and the set gate delay has expired, and it interrupts the
measurement as soon as the defined gate length is reached. With the gate signal
becoming active the next time the measurement is resumed etc.
Pulsed signals can be measured by this method, if the gate delay and gate length
are selected in a way that the measurement is only performed while the pulse is
active. Gated measurements are possible in the frequency domain (span > 0) and
the time domain (span = 0), but it is available only in combination with an external
gate signal.
Note that gated trigger is not available if you are using a forced FFT sweep (see
Selecting the Sweep Type).
● Internal Trigger
A sweep is triggered with an accurate, internal clock.
You can use this trigger, for example, to trigger on time domain based signals,
and, in combination with a gated trigger, hide the uplink or downlink information in
the signal.
To use the internal trigger for this scenario, proceed as follows:
- Define the frequency, the span, the RBW and the amplitude parameters.
- Define the time bases of the internal clock in Hz. These should correspond
with the time domain setting of the injected RF signal.
Example: TD-LTE = 100Hz
- With the "Gate Settings" ("Gate Length" and "Gate Delay"), select the signal
you are interested in. (See below for more information about gate settings.)
- Turn on the gated trigger.
Note that the internal trigger is available for devices with a serial number > 121000
Including a Delay Time
When you are using a video trigger in the time domain or an external trigger, you can
delay the start of the measurement with respect to the trigger event by entering a delay
time. In this way, you can include time differences between the trigger event and the
measurement. The range of the trigger delay is from 0 µs to 100 s. The resolution
depends on the subrange.
To Next Page
Loading...
