North East Systems Associates, Inc.




About NESA
Site Map
Useful Links
Contact Us

Electromagnetic Interference and Signal Integrity Principles

See also:
Power Sys. Design
SI Fundamentals
High Perf. Design
->EMI and SI
SI Principles
SI for Digital Designs

A Two Day Seminar

Course Description:

This seminar will provide the participants with a background into EMI principles and international measurement standards and authorities. Following the introductory EMI topics, the seminar will consider signal integrity and design principles for low EMI emissions. Topics in this section include power supply EMI, parasitic coupling, "ground bounce" delta-I noise, bus terminations and bonding and shielding for I/O cabling.

Course Objective:

At the end of this seminar, participants will understand the principles of EMI, bonding and shielding, and the international emissions standards. Lastly, participants will have been exposed to the relationship of specific digital electronic design parameters to EMI performance.

Who Should Attend:

  • Logic and signal integrity engineers designing digital computer, telecommunications and industrial systems.
  • EMI engineers responsible for compliance of digital computer, telecommunications and industrial systems.


Course Curriculum:


Day 1 - Part 1: EMI Principles and Measurements:

Electromagnetic Interference (EMI) Signal Theory

  • Spectral Decomposition of Digital Signals - Fourier Analysis

Antenna sources and radiation field properties of EMI

  • Dipoles - Common Mode (CM) EMI sources
  • Magnetic Loops - Differential Mode (DM) EMI sources

Practical sources of EMI Radiation

  • Parasitic and unbalanced coupling as sources of EMI radiation
  • Grounding and (delta-I) noise in electronic devices
  • Poor I/O cable bonding and shielding

Power System Considerations of EMI

  • Switching power system fundamentals for EMI
  • Common mode EMI coupling in power supply packaging
  • Common mode and differential mode EMI in DC power distribution
  • Common mode and differential mode coupling in power cords

System considerations of Conducted and Radiated EMI

  • System grounding - single point vs. multi-point grounding
  • EMI sources between power system and backplane
  • Multi-cabinet signal cabling, and grounding
  • Logic return ground vs. chassis ground

Day 1 - Part 2: EMI Measurement Techniques and International Compliance Standards:

Open Field Site Test Requirements

  • The open field E-Field measurement site requirements
  • The open field Magnetic field measurement site requirements

Federal Communications Commission (FCC) emission limits

  • Class A industrial, 10 and 30 meter limits
  • Class B home and retail 3 and 10 meter limits
  • FCC required measurement techniques

Verein Deutsche Electronishe (VDE) emission limits

  • Class A industrial
  • Class B home and retail
  • VDE required measurement techniques

C.I.S.P.R. Radiated and Conducted EMI Limits - CE Mark Requirements

  • Class A industrial
  • Class B home and retail
  • C.I.S.P.R. required measurement techniques
  • CE Mark Requirements

Day 2 - Part 1: EMI Measurement Techniques and International Compliance Standards:

System lateral size and the effects on measurements 3 meter vs 10 vs 30 meters

  • Far field estimates and beamwidth
  • EMI wavelength effects as function of system size and cable length
  • Compliance measurement effects of system size

Day 2 - Part 2: Putting Good Signal Integrity Together with Good EMI Design:

  • Power supply packaging and power distribution for low EMI emissions
  • Relationship of crosstalk and coupling to EMI emissions
  • Reduction of parasitic and unbalanced coupling to reduce EMI radiation
  • Delta-I EMI noise reduction by proper grounding in electronic device, connector and cable packaging.
  • Bus terminations and backplane grounding for low EMI designs
  • I/O cable bonding and shielding for EMI radiation reduction

Day 2 - Part 2 - Discussions of Client Designs



[About NESA] [Services] [Seminars] [News] [Publications]
[Home] [Site Map] [Search] [Useful Links] [Contact Us]

Copyright (C) 1998 - 2013 North East Systems Associates Inc.
For warranty, copyright & license information see the Legal Notices