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Innovative Signal
Generation of Complex
Waveforms for Improved
Testing
Dave Martinez
August 1986
RJ ~ Microwave
Measurement
Symposium
and
Exhibition
FliD'8 HEWLETT
~~ PACKARD
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Modern electronic design often requires an accurate source of complex signals to accurately test a sys-
tem's true performance. But the availability and accuracy of these signals has limited their use. This
paper describes how the new, high-performance 125 Megasample/sec HP 8770S Arbitrary Waveform
Synthesizer system can generate these "real- life" signals to improve testing. Theory and examples of sig-
nal simulation are presented to show the system's flexibility to generate almost any signal up to 50 MHz.
Also covered are applications such as modeling a filter's response, margin testing, and a discussion of
ATE considerations.
Author: Dave Martinez, Product Marketing Engineer, Stanford Park Division, Palo Alto, CA. BSEE Stanford
University, 1982. With HP since 1983, working with RF & Microwave power meters and the HP 8770S
Arbitrary Waveform Synthesizer system.
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Innovative Signal Generation
of Complex Waveforms for
Improved Testing
AWSP1
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Outline
1. Total performance testing and how
it improves product control.
2. Digital Signal Synthesis- A new
concept for generating signals.
3. Signals that this new concept can
generate.
4. Integrating this new concept with
existing test systems.
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Ideal Radar
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Transmitted Pulse
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Receiver Video Signal
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But real radars and other systems
must deal with non-ideal effects.
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Modern electronic systems have to work with non-ideal signals in non- ideal enviroments. For example, a
radar finds a target by detecting the return pulse that is reflected off the target. Many types of distortion
can make this difficult to do. Bandwidth limitations can cause ringing or overshoot on the return pulse.
Or reflections from the surrounding enviroment can cause clutter that might hide the desired pulse. Parts
of the receiver itself may introduce distortion.
Sometimes these non-ideal effects can limit the performance not just of radar systems, but of any
electronic system. But testing a system's tolerance to distortion has been a difficult task because of the
limited availability of precise test signals that simulate distortion. If these signals are not available, it is dif-
ficult to verify the total performance of a system.
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Typical Design Question: How will
my system react to different...
- Bandwidths?
- Clutter?
- Signals/Noise?
- Time-delays?
- Amplitude & Phase
Non-lineartities?
- Other Distortion?
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A designer sometimes has many questions about his system's performance. The answers to these ques-
tions determine his system's total performance specifications. Finding the answers often requires test sig-
nals whose parameters can be precisely varied to test a system's response.
Without these test signals, a designer sometimes has to estimate the performance limit of his system and
then add a large guard-band. Or other times, tests are not done and some system characteristics are not
specified.
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Generating "Real-Ufe" Test Signals
Required Specialized Test Equipment
NON-DISTORTED TEST TEST
SIGNAL SET SIGNAL
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Specialized test sets have limited flexibility.
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Many times specialized electronic test sets were designed to provide test signals representive of actual
system operation, but they were limited in their flexibility. Many times these test sets couldn't provide dif-
ferent signals if new signals were needed for new tests. Often entire test sets had to be scrapped once
their particular program had ended.
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Digital Synthesis Provides Test
Signal Generation Flexibility
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