Datasheet

Page 16
Find us at www.keysight.com
Viewing the frequency content of waveforms is greatly simplified
by a dedicated FFT button and level adjustment knobs� Pop up
keypads make inputting start, stop, span and center frequency
easy� And the new problem solving feature called “gated FFT”,
unique in this class of instrument, lets you time correlate the
analog, digital, and frequency domain to aid in analysis and
debug� In addition, there are new capabilities for peak searching,
max and min hold and averaging of FFTs to increase dynamic
range�
When gated FFT is on, the oscilloscope goes into zoom mode�
The FFT analysis shown in the zoomed (bottom) window is taken
from the period of time indicated by the zoom box in the main
(top) window� In the gated FFT mode, touch and flick the zoom
box through the acquisition to investigate how the FFT analysis
changes over time, correlating the RF phenomenon with the
analog and digital phenomenon�
Figure 21a through 21d show a simple gated FFT example
observing a RF signal frequency transition from 400 MHz to
200 MHz, time correlated to both the SPI controlling signal
(digital) and a VCO enable signal (analog)� Note, you can also
visualize the RF signal itself in the time domain to gain additional
insight such as a gap in the RF time domain waveform�
Figure 21a� Triggered on a SPI command, the RF signal is still at 400 MHz
as indicated in the frequency peak search result lister�
Figure 21b� No RF activities in this zoomed time�
Figure 21c� Start observing the RF signal at 200 MHz� You can validate
this from the RF analog waveform as well�
Figure 21d� RF signal settled down at 200 MH as indicated in the search
lister�
Solve: Dedicated Frequency/Spectrum Analysis Allows you to Time-Correlate
Analog, Digital, and frequency Domain Signals in a Single Instrument