Keysight Technologies C Series - Page 202

202 Keysight N9915-90020 User’s Guide
SA (Spectrum Analyzer) Mode (Option 233–Mixed Analyzers)FUTURE
SA Mode Settings
important when using RF Burst or Video triggering in wider spans, because the
signal providing those triggers has limited bandwidth. Learn more about Auto
trigger in
“Auto Trigger Time” on page 200.
For more conceptual information on this topic, please refer to Spectrum
Analysis Basics (App Note 150), pages 31 - 35, at
https://www.keysight.com/us/en/assets/7018-06714/application-notes/595
2-0292.pdf
.
How to set FFT Gating
1. Create a non-zero span measurement. Wider frequency spans take more
time to acquire.
2. Press Sweep 3
> Trigger Settings > FFT Gating Setup
3. Then choose from the following:
— Gate View OFF ON When ON, a separate zero span measurement is
displayed below the non-zero span window. The gate view
measurement helps to configure the gate width and delay by
revealing (with green markers) the location of the gate relative to
the trigger event. The zero span measurement is tuned to the center
frequency of the non-zero span measurement with about 5 MHz of
bandwidth. The Y-axis scale is the same for both windows.
—
Gate View Time Set the X-axis span for the non-zero span window.
Enter a value using the numeric keypad, the arrows, or the
rotary knob. This value is annotated as Swp (nn) below the window.
—
FFT Gating OFF ON When ON, the trigger type, gate width, and
delay are applied to the non-zero span measurement. The Res BW is
set to a value that is inversely proportional to the gate width.
—
Gate Width Set the width of the gating area within the non-zero
span window. The gating area is indicated by two vertical green
lines. Enter a value using the numeric keypad, the arrows, or
the rotary knob.
—
Gate Delay
Effectively moves the gating area left (negative delay) or
right (positive delay) relative to the trigger event. Enter a value
using the numeric keypad, the arrows, or the rotary knob.
When you have properly setup the Gate Trigger, Width, and Delay using the
Gate View measurement, you can turn Gate View OFF to return to the full
screen non-zero span measurement with FFT Gating ON, the RBW set, and the
Trigger settings active.