Basics   I   FAQs   I   Application Notes   I   Featured Resources

EMI & RFI

Training Center Classroom

Welcome to this installment of EE Classroom on EMI and RFI


Electromagnetic interference. Radio frequency interference. It’s all interference to you and your design unless you have a near-constant vigil of what can be causing it and what steps to take to avoid it. And, of course, this isn’t the type of interference that is simply annoying; it can be mission-critical. It’s the type of interference that can disrupt electronic devices, equipment, and systems ranging from cellphones to solar cells on spacecraft. 


Now is the time to drop-in to this classroom and get up close and personal with EMI and RFI. Get a basics refresher, a standards lowdown, and tips on testing — the understanding of which can also be mission-critical to your design.


So shut the door, turn off the phone, hang up a do-not-disturb on your door while you read through these tutorials. Make this your own personal design of non-interference.

Aimee Kalnoskas

Senior Editor, EE World Online

EMI & RFI Classroom sponsored by:

Basic  •  Standards

When EMF becomes EMI

What is EMI and how can you prevent it?

Conducted and coupled EMI/EMC concepts

With signals at radio frequencies (RF), mutual inductance becomes more of a problem than resistance.

EMI is an electromagnetic emission that causes a disturbance in another piece of electrical equipment.

Reducing emissions also often results in lower EM susceptibility and improved system performance.

Inductors  •  Ferrites  •  Filters

EMC/EMI design and the use of board-mount dc/dc converters

Choosing inductors or ferrite beads for power supply filtering

What are RF inductors?

Magnetism, electromagnetism,

and inductance

RF inductors have several uses and are available in various construction types to suit the performance needs of specific applications.

EMC and EMI are system-level considerations that have implications for power system design.

Simply adding some inductance to clean up a switching regulator output seems like a good idea but it isn’t that straightforward.

To understand inductance, it is important first to understand magnetism and electromagnetism.

Testing  •  Compliance

EMI, EMC, EMS, and the ITU

You passed: Getting products through EMC/EMI compliance tests

Noise quantification and measurement

A scope-based technique for optimizing EMI input filters

Ensuring EM compatibility at a specified level and operating conditions is a common demand in the almost all electronics designs.

In choosing a way to mitigate electronic noise mitigation, it is necessary first to quantify it and ascertain its source.

Pre-compliance tests run in your own lab can avoid band news when products go into formal checks.

A simple oscilloscope setup can size common-mode and differential-mode noise filtering components separately and more accurately.

FEATURED RESOURCES

Common Mode Filter Chokes for High Speed Data Interfaces

A Guide to Understanding

Common Mode Chokes

What is an LC Filter?


Wirewound Ferrite Beads: Outperforming Traditional

Chip Ferrite Beads

Headquartered in Cary, IL, Coilcraft has been a leader in the design, manufacture and distribution of high-performance magnetic components including RF chip inductors, power magnetics and filters since 1945. In addition to the industry’s largest selection of standard, off-the-shelf components, we also design and build custom magnetics to meet your precise requirements.


With manufacturing, distribution and engineering facilities across North America, Asia, and Europe, Coilcraft provides fast service, shipping, and response times, regardless of where you are in the world. Our global footprint allows us to produce components in multiple locations to support customers around the world and dramatically outperform industry-average lead times.