Electromagnetic Compatibility & Signal Integrity

‌Dr. Thomas Van Doren

Professor Emeritus, Missouri S&T

Electrical & Computer Engineering

 

Dr. Van Doren has conducted research and education in electromagnetic compatibility for the past 30 years. More than 19,000 engineers and technicians from 105 companies and government agencies have attended his Grounding and Shielding and Circuit Board Layout courses.

Grounding and Shielding of Electronic Systems

(How to Diagnose and Solve Electromagnetic Interference and Signal Integrity Problems)

A 2-Day Lecture/Demonstration Presentation


Cost and Scheduling

The total costs for the 2-day Grounding and Shielding of Electronic Systems course is $19,800, for a maximum of 35 participants; or $13,000 for a maximum of 20 participants. These prices include all travel expenses in the continental U.S. and one copy of the course notes for each participant. Please email Tom Van Doren at vandoren@mst.edu or call him at 573-578-4193 to schedule an in-house presentation.


Course Description

Most engineers and technicians using or designing electronic systems have not had formal training concerning grounding and shielding techniques. Learning how to solve electromagnetic interference and signal integrity problems on the job can be very expensive for the employer and frustrating for the engineer. Most of the electromagnetic and circuit principles involved are simple. However, the complexity of many systems masks the logic and simplicity of possible solutions.

This course: treats signals as currents; explains fundamental grounding, shielding, and signal routing principles; clarifies troublesome terminology; and demonstrates many techniques for identifying and fixing electrical interference problems. The principles will be described as concepts rather than theoretical equations. The emphasis on concepts will make the course useful for people with a wide range of experiences. Several interference mechanisms and shielding techniques will be demonstrated.

Some of the Course Benefits

This course will help engineers and technicians to:

  • Use logical procedures, more than ‘trial-and error’, to reduce noise problems;
  • Improve the signal integrity of high-speed digital waveforms;
  • Reduce the time and cost required to meet emission and susceptibility specifications;
  • Determine the optimum grounding technique for both safety and low noise;
  • Recognize that all electrical interference problems are caused by four basic coupling mechanisms (conducted, magnetic fields, electric fields & electromagnetic waves); and,
  • Determine the correct connection for the shield on a twisted pair cable. 
  • First Day
  • Second Day

First Day

                                             

1.  Introduction

2. Current Routing & Least Impedance
Understanding wiring inductance 
DEMO: Path of least impedance 
Controlling the current return path

3. Interference Coupling Mechanisms
Review of the 4 coupling mechanisms 
Ways to recognize the dominant mechanism 
Equivalent circuit for each mechanism

4. Field Containment, Bandwidth Balance & Resonance   
Routing to provide field containment   
DEMO: Fields emitted by a coaxial cable   
Relating bandwidth to transition time   
CM currents and impedance imbalance   
Resonances in lumped & distributed circuits   
DEMO: Predicting & reducing resonances

                                   

5. Grounding for Safety and Noise Reduction    
Signal routing is not the same as grounding    
Characteristics of a ground structure    
Safety grounding examples    
Single point versus a ground grid    
Avoiding kHz ground loops   
Grounding analog and digital circuits    
Grounding signals to chassis for RF & ESD immunity and to reduce RF emissions

6. Interference Diagnostic Techniques    
Diagnostic analysis & measurement tools    
How to determine the dominant mechanism    
The influence of circuit impedance    
Diagnostic measurement techniques    
Using current and E & H field probes

 

Second Day

                                               

Review of First Day

7. Filtering to Reduce Conducted Noise    
Current blocking & diverting strategies    
Types of filters    
CM and DM filter techniques    
GHz filtering techniques    
Reducing capacitor mutual inductance    
When to use ferrite beads

8. Field Containment Using Self Shielding   
The low cost & wide bandwidth approach    
Signal routing provides the containment    
DEMO: Twisted pair versus coaxial cable    
Misuses of twisted pair

 

                                               

9. Reducing Capacitively Coupled Noise    
DEMO: Capacitive shielding example    
Capacitive noise reduction options    
DEMO: Shield connection for twisted pair

10. Reducing Inductively Coupled Noise   
Reducing mutual inductance    
Eddy current shielding    
Magnetic flux shunting    
DEMO: Magnetic shielding options

11. Electromagnetic Wave Shielding   
Skin effect & RF containment    
Making cable shields effective at GHz    
Sizing air flow openings    
Controlling CM currents    
EM containment is more important than grounding




Questions?

Contact Us

Registration Contact

Dr. Thomas Van Doren
Missouri University of Science and Technology
Electrical & Computer Engineering¿ - EMC Lab
Rolla, MO  65409
Phone: 573-578-4193
Email: vandoren@mst.edu