Grounding and Shielding of Electronic Systems: How to Diagnose and Solve Electromagnetic Interference and Signal Integrity Problems

Details TBA

Location
Senate Gallery
Corbett Student Center
New Mexico State University
Las Cruces, NM 88011

Instructor
Dr. Tom Van Doren
Professor of Electrical & Computer Engineering
Electromagnetic Compatibility Laboratory
Missouri University of Science & Technology
vandoren@mst.edu 573-341-4097


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.

 

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

Course Outline

FIRST DAY

Introduction

Current Routing & Least Impedance

Understanding wiring inductance
DEMO: Path of least impedance
Controlling the current return path

Interference Coupling Mechanisms

Review of the 4 coupling mechanisms
Ways to recognize the dominant mechanism
Equivalent circuit for each mechanism

Field Containment, Bandwidth, Balance and 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

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

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

Brief review of First Day

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

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

Reducing Capacitively Coupled Noise

DEMO: Capacitive shielding example
Capacitive noise reduction options
DEMO: Shield connection for twisted pair

Reducing Inductively Coupled Noise

Reducing mutual inductance
Eddy current shielding
Magnetic flux shunting
DEMO: Magnetic shielding options

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

Fee/Registration

Registration fee will be US$795 for 1-4 students from your organization)
US$750 for 5-9 students
US$725 for 10 or more students

Early registration:  Discount US$25 for each student

Registration Details TBA

Suggestions for Accommodation

There are a number of motels close to New Mexico State University. The following are listed approximately from closest to farthest of course location; all are within about 2 miles of course location.

Area code is 575 (except where noted)
 

Comfort Suites 2101 S. Triviz (I-25 off University Exit) 522-1300  Sleep Inn (I-25 off University Exit) 2121 S Triviz Dr. 522-1700 Value Place (extended stay) (I-25 off University Exit) 2080 S Triviz Dr. 1-800-valueplace Ramada Palms de Las Cruces 201 E University Avenue 526-4411 Plaza Suites 301 E. University Avenue (I-25 off University Exit) 525-2083

Holiday Inn Express 2635 S. Valley Dr. 527-9947 Comfort Inn of Las Cruces I-10 off University Exit 2585 S. Valley Drive 527-200  Motel 6 235 La Posada Lane 525-1010  Super 8 Motel 245 La Posada Lane 523-8695  Hotel Encanto (Encanto Hotel de Las Cruces) 705 S. Telshor Blvd 522-430  Best Western Mission Inn 1765 S. Main 524-8591