High Frequency Measurement Techniques


 Measuring signal and noise waveforms in high speed digital circuitry, switching power supplies, or in the presence of interference such as ESD can easily produce erroneous results.  This one-day seminar discusses several sources of error that can occur in making laboratory measurements on electronic circuits utilizing frequencies in the hundreds of megahertz range.  Special attention is paid to high frequency effects on scope and current probes, and pickup loops.  Proper measurement procedures, as well as inexpensive and easy-to-build noise measuring probes are described.  The techniques discussed are equally useful for high frequency signal and/or noise measurement.  Each technique is demonstrated through in-class experiments and demonstrations.

 This seminar is presented by Douglas C. Smith, author of the book, High Frequency Measurements and Noise in Electronic Circuits.  Many of the techniques presented were developed by Mr. Smith and originally published in his technical papers and book.

This seminar is also offered in a two day format.  The two day version adds more in-depth information on signal integrity measurements and provides time for additional demonstrations.


Outline

INTRODUCTION & TECHNICAL BACKGROUND

 Review of Theoretical Concepts
 Inductive Voltage Drop
 Transformer Action (Mutual Inductance)
 Coaxial Cables
 Capacitive voltage divider
 The "Null Experiment"
 

SCOPE PROBE EFFECTS

 Probe Grounding
 Probe Resonance
 Ground Noise Currents
 Probe Compensation
 Effective Probe Bandwidth
 Single Ended & Differential Probes
 Use of Ferrite Cores
 Useful Home Built Probes
 

CURRENT AND MAGNETIC FIELD PROBES

 Direct vs. Indirect Measurements
 Magnetic Loop
 Current Probes
 Two Loop Technique Using Phase Information
 Noise Injection Techniques
 

DEMONSTRATIONS

 Scope Probe Effects
 Indirect Measurements
 Cable Shield Terminations
 The Use of Ferrite Cores on Probes


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Henry Ott Consultants
48 Baker Road Livingston, NJ 07039
Phone: 973-992-1793,   FAX: 973-533-1442
e-mail: h.ott@att.net

June 26, 2001