Keysight Technologies FieldFox A Series, User Manual

Page: 269 / 756

Keysight N9927-90001 User’s Guide 269
IQ Analyzer (IQA) – Option 351 (CPU2 Only)
I/Q Analyzer (IQA) Mode Settings
refresh rate when the acquisition time is long. Changing the Stop
Time changes which data point is displayed on the right side of the
screen.
Couplings: When the change of Stop Time makes time domain
display length exceed the limitation, the Start Time will change to
satisfy time domain display length limitation:
——The maximum value is determined by current Sample Rate and
the maximum capture samples.
——Stop Time is adjusted to the nearest sample point based on the
Sample Period.
——The maximum time domain display length is 524,288 points.
Time Domain Display Length [pts] = {[Sample
Rate[pts/s] x (Stop Time[s] - Start Time[s])] +
1}
Where:
pts = points
s = seconds
— Trigger Settings Opens the Trigger Settings softkey menu.
Then:
—— Trig Type Then select one of the following:
Softkey Description
Free Run
(Default.) – Triggering is provided by the FieldFox internal
circuitry. A new acquisition begins when the previous
acquisition ends.
External
An acquisition is triggered on an external TTL signal at the
Ref In/Trig In connector on the FieldFox top panel.
Choose to trigger on the rising slope at about 1.7 V or on
the falling slope at about 1.0 V using the Trigger Slope
setting (below).
Video
An acquisition is initiated when the displayed amplitude
of an incoming signal crosses the settable Trigger Level.
This selection can detect low-amplitude signals, but also
has been filtered considerably and may not be a true
representation of the incoming signal.
RF Burst
An acquisition is initiated when the signal at the third IF
(analog) stage crosses the settable Trigger Level. This
selection offers a wider bandwidth and may be a better
representation of the incoming signal than Video trigger.
However, RF Burst is not as sensitive to triggering on
low-level signals.