Use of a CDN for radiated emissions testing.

[trevwhite]

Hi, had posted this message in reply to another post but think it's probably a topic of its own.

Had an led driver connected to an led pcb fail initial radiated emission testing. Got the following update from the led driver manufacturer when asking about their emissions testing.

"Measurement of Radiated electromagnetic disturbances (Radiated Emissions) in band 30-300MHz - normally you have to have chamber with special antenna in 10m distance from DUT, but there is alternative method called "CDN method" and this measurement we provide to them. "

Anyone got any links to how CDN method is implemented and what is required? It sounds interesting if that can be used instead of a test chamber for initial pre approvals testing.

Trev

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[chris_leyson]

Coupling/Decoupling network originally designed for coupling RF into cables for immunity testing but it was found that they worked backwards as well and there is some correlation with radiated emissions. They're a high frequency version, 30 to 300MHz of a LISN but I think their use is limited to certain applications and "luminaries" is one example. It's a lot easier than a 30m test site and I would love to find out about some of the theory behind CDN measurement principles.