NTS News Center

Latest News in Testing, Inspection and Certification

NTS News Center - Latest News in Testing, Inspection and Certification

Reverberation Chamber Workshop at NTS Plano

On Thursday, November 10, 2016, NTS is hosting its second workshop on reverberation chamber technology at our Plano facility.* Sponsored by ETS-Lindgren and NTS Plano, this is a free, hands-on, half-day workshop open to those that are interested in learning about reverberation chamber test methodology including new applications for this versatile and robust test environment.

Reserve your seat today – space is limited!
This is a free event; please register by November 8th to ensure adequate seating and catering.

Event Details

Date and Time
Thursday, November 10, 2016
12:30pm – 6:00pmLocation
1701 East Plano Parkway #150
Plano, TX 75074

(972) 509-2566
Itinerary

12:30pm – 1:15pm
Complimentary lunch and registration

1:15pm – 5:00pm
Presentations including Q & A

5:00pm – 6:00pm
Reverberation Chamber Testing Demonstrations

Contact

For specific questions about this workshop or to confirm your registration, please contact Janet O’Neil, ETS-Lindgren and IEEE EMC Chapter Vice-Chair, at (425) 443-8106 or j.n.oneil@ieee.org.

Reverberation Chamber Workshop Coming to Fullerton!

reverb-600x240We are pleased to announce that we will be hosting the IEEE Los Angeles EMC Chapter and MTT/AP Joint Chapter Meeting at NTS Fullerton, CA location on October 17.

This workshop will address fundamental to advanced topics regarding reverberation chamber test methodology, including the new applications for this versatile and robust test environment. Once mainly used for Government test requirements, the reverberation chamber is increasingly being used for aerospace, automotive and consumer electronic test applications due to its inherent efficiencies in cost and time. Practical, application oriented material will be provided that you can use on the job. The workshop concludes with a live demonstration of a EUT using the reverb chamber at NTS.

Speakers include Garth D’Abreau, Director of Automotive Solutions at ETS-Lindgren, Dr. Vignesh Rajamani, Senior Associate at Exponent, and Jeff Viel, Corporate Director of EMC at NTS.

Click here for more information and to register. If you would like more information about the NTS Fullerton reverberation capabilities, click here.

NTS Quick Guide to Reverberation Testing

Picture4

Inside the RF chamber

A reverberation chamber (mode tuned/mode stirred chamber) is a shielded enclosure or resonant cavity for RF testing which is statistically isotropic, random polarity, having RF uniformity within specified limits. Typically it has a paddle (or tuner) which stirs up the field, randomizing the boundary conditions. Mode tuned is where the paddle is stepped to a position and then RF is applied for a dwell time sufficient to exercise the equipment. Mode stirred is when the paddle is continually turned with RF energy applied for a full paddle revolution. Reverb chambers are useful for radiated susceptibility, radiated emissions (total radiated power), shielding effectiveness, and many other troubleshooting scenarios.

The benefits to reverberation testing are numerous. RF is applied to all exposed sides of the device under test (DUT) during a full 360° turn of the paddle, instead of a single side. For direct illumination testing, many standards require the all apertures of the DUT to be illuminated. On complex items this can be difficult – even impossible. Window effects testing, required when applying direct illumination, is not required during reverb testing because the field intensities are constantly changing. SAE ARP 5583 states that the reverb is the recommended and preferred method to show compliance for large and/or complex Level A (flight critical) systems. Test repeatability is much easier to obtain in a reverb chamber with proper processes, and running the test is much less complex than a single aspect angle test. Antenna distance, aim (focus), 3 dB beam width, location of the field probe, EUT layout, and location of the EUT in the working volume are all less of a factor in the repeatability of test.

Picture6

A view from outside

You should know if reverberation testing is right for your program. Reverb chambers are random in polarity which makes it challenging in determining directivity of RF energy. Testing multiple field levels on a system, such as outside the pressure vessel level and inside the pressure vessel level, can be difficult; all equipment in the chamber is exposed to the same field. There are limitations on pulse width due to a high Q (efficient) chamber having large amount of stored energy. If you have small, simple equipment, single aspect angle tests may be faster and sufficient for test coverage. There are ways to compensate for each, and an NTS engineer can help with suggestions or assist you with a test plan.

Both direct illumination and reverberation test methods are acceptable paths to certification. They both have benefits and drawbacks that champion each as a test method. Fortunately, NTS has the ability to test in both methods and the engineering expertise to support your path to certification.

For more detailed information about reverberation testing at NTS Rockford, Fullerton, Plano, Tempe, or Boxborough, call 800-270-2516 or email us at sales@nts.com. Request a quote today!

Understanding Testing in a Reverberation Chamber

REVERB

A reverberation chamber (mode tuned/mode stirred chamber) is a shielded enclosure or resonant cavity for RF testing which is statistically isotropic, random polarity, having RF uniformity within specified limits. Typically it has a paddle (or tuner) which stirs up the field, randomizing the boundary conditions. Mode tuned is where the paddle is stepped to a position and then RF is applied for a dwell time sufficient to exercise the equipment. Mode stirred is when the paddle is continually turned with RF energy applied for a full paddle revolution. Reverb chambers are useful for radiated susceptibility, radiated emissions (total radiated power), shielding effectiveness, and many other troubleshooting scenarios.

The benefits to reverberation testing are numerous. RF is applied to all exposed sides of the device under test (DUT) during a full 360° turn of the paddle, instead of a single side. For direct illumination testing, many standards require the all apertures of the DUT to be illuminated. On complex items this can be difficult – even impossible. Window effects testing, required when applying direct illumination, is not required during reverb testing because the field intensities are constantly changing. SAE ARP 5583 states that the reverb is the recommended and preferred method to show compliance for large and/or complex Level A (flight critical) systems. Test repeatability is much easier to obtain in a reverb chamber with proper processes, and running the test is much less complex than a single aspect angle test. Antenna distance, aim (focus), 3 dB beam width, location of the field probe, EUT layout, and location of the EUT in the working volume are all less of a factor in the repeatability of test.

REVERB2You should know if reverberation testing is right for your program. Reverb chambers are random in polarity which makes it challenging in determining directivity of RF energy. Testing multiple field levels on a system, such as outside the pressure vessel level and inside the pressure vessel level, can be difficult; all equipment in the chamber it is exposed to the same field. There are limitations on pulse width due to a high Q (efficient) chamber having large amount of stored energy. If you have small, simple equipment, single aspect angle tests may be faster and sufficient for test coverage. There are ways to compensate for each, and we can help with suggestions or assist in creating a test plan.

Both direct illumination and reverberation test methods are acceptable paths to certification. They both have benefits and drawbacks that champion each as a test method. Fortunately, NTS Rockford has the ability to test in both methods and the engineering expertise to support your path to certification. Should your project require this type of testing don’t hesitate to contact the lab directly at (815) 315-9250 and speak to one of our engineers!