Demystifying Conducted Immunity Tests - Pitfalls, Calibration & Testing

IEC 61000-4-6 is widely used for compliance testing of RF immunity of apparatus for the EMC Directive. It applies an RF stress over the frequency range 150kHz-80MHz to the cables connected to the equipment under test (EUT) to determine its immunity to this stress.
The principle of the test is to excite both electric and magnetic disturbance fields within the EUT by applying the stress in common mode with respect to the ground reference plane (GRP) to certain selected cables entering it. The stress is applied through a defined source impedance of 150Ω, which is also taken to be the impedance of other cables connected to the EUT. Therefore we must use networks to stabilise this impedance or to decouple it, so as to ensure that unwanted variations have little effect on the test; and also make sure that the layout of the test is controlled so that variations due to stray coupling are minimised. This video demonstrates the point.
Note: From 10:50, my colleague and friend Peter Green has kindly pointed out that most off-the-shelf signal generators will automatically switch to higher amplitude when enabling AM. In this case, we are using a signal source from the tracking generator of a spectrum analyser, and we use the AM function of the amplifier, hence the difference.
Useful Link www.tekbox.com/product/Conduc...
CHAPTERS
00:00 Introduction - The commonly seen immunity issues
02:54 Why do we perform conducted immunity tests?
06:03 Basics
14:06 Calibration
23:43 Performing the conducted immunity test

[@CLGilbert]

Great Video. I'd love to see more of the lab setup. The ground sheets. How they are placed and tied together etc.

[@jluke6861]

Thank you for making this video. You explain things very well.

[@Basilic3]

Thank you for this video which presents well what is achievable in pre-compliance. We are facing non-compliance at work and we plan to invest in equipment for immunity tests, as we cannot replicate the tests internally (and therefore correct them safely). We already have equipment for emission tests (R&S FPC1000 9 kHz-3 GHz, LISN, and antennas). We now need a signal source, and we also need to purchase amplifiers to achieve industrial immunity levels (level 3). Would it be wiser to buy a new spectrum analyzer with a generator, such as the SSA3075X with EMCView Pro, or a generator like the SSG5060X?

[@oly463]

great video, thank you

[@carlosagorreta5276]

Thank you for the video!

[@sherm_92]

Great video as always, thankyou