Waveform Recording With The Hp 3562A; The Time Capture Preset Measurement; Frequency Domain Analysis - HP 3562A Operating Manual

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Chapter
Waveform Analysis with Time Capture
Waveform Recordi ng with the H P 3562A
The Time Capture Preset M easu rement
Time Domai n A nalysis
F requency Domai n Analysis
I ntrod uction
Waveform analysis is typically performed with storage or dig itizing oscilloscopes or a
family of products known as waveform recorders. The basic technology i n these
devices is identical to the fi rst stage of all FFT-based signal analyzers: analog signals
are sam pled , dig itized and stored for l ater analysis. Consequently, many Dynamic
Sig nal Analyzers such as the HP 3562A provide waveform recording capabil ities as
an extension of thei r frequency domai n analysIs fu nctions.
While the sampl i ng frequency of Dynamic Sig nal A nalyzers is typical l y 80 times lower
than typical waveform recorders (256
g reater than 1/2 the sam pling frequency; refer to t o
20 40
plete filtering to prevent " aliased " f requency components, caused by i n put signals
details.
Thus, the frequency and dynamic range of the application dictates which device
provides the opt i m u m solution. Waveform analysis applications such as speech rec­
ognition and synthesis, audio analysis, mechanical transients and electronic wave­
forms below 1 00 kHz can be add ressed by properly equ i pped Dynamic S i g nal
Analyzers.
Waveform Recording with the H P 3562A
The HP 3562A provides a 20, 480-sam ple buffer for waveform record i ng with a
256 kHz
i n put channel for as many as 10 consecutive time records contai n i ng frequencies u p
to 1 00 kHz.
displayed and annotated resu lts. The Time Captu re mode is enhanced with complete
triggering capabil ities (i ncludi ng pre- and post-trigger delay) and post-capture zoom
analysis with up to
The exam ple i n this chapter demonst rates waveform analysis i n the audio range; the
actual measu rement will be performed using the Time Capture preset state. Pri mary
em phasis is g i ven to analysis of the captured data in both the time and frequency
domains, i ncluding post-measurement zoom analysis.
kHz
d B better with a DSA. A l s o , most Dynamic Sig nal Analyzers provide com­
sampling rate: real-time or "gap free" data can be recorded from either
Analysis can be performed i n both the time and frequency domains with
10
times the original frequency resolution .
versus 20 M Hz), dynamic range is usual l y
HP Application Note 243 for fu rther
Waveform Analysis with Time Capture
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