How does an EMI Receiver work?

The EMI receiver is the standard measuring device of every EMC test measurement setup. This video explains both the basic principle of the superheterodyne receiver and the necessity of the individual components in the block diagram. Special attention is paid to the choice of the different detectors in the measurement device. At the end of the video, a laboratory example shows the handling of the EMI receiver and the effects of the quasi-peak detector.
Tutor: Ko Odreitz
Chapters:
00:00 - Intro
00:33 - Motivation
01:59 - EMI receiver in general
03:15 - Superheterodyne receiver
06:33 - EMI receiver vs. spectrum analyzer
08:47 - Block diagram
11:48 - Detectors
14:56 - Lab example theory
18:23 - Lab example practice
21:28 - Measurement
24:04 - Recommended literature
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[@pastorericardo]

Very good indeed! Make it all simple, it is so dificult to find someone with this synthesis skills.

[@ife.tugraz]

Thank you for the nice feedback :)

[@vw1114]

Great introduction on EMI receivers! Thanks for your work!

[@ife.tugraz]

You're welcome. We are glad you like it :) We would appreciate it, if you could recommend us to others.

[@koodreitz]

Thank you for your kind feedback!

[@jluke6861]

What a great video and the great explanation. I just subscribed to your channel and turned on the bell. Your effort and time is appreciated.

[@bramhadeosawale9187]

Very well explained. I was looking for such Videos. Thanks

[@ife.tugraz]

Thank you for the nice feedback. We have even more videos on EMC and basics of electronics available on our channel :)

[@Janusandersen]

This is very cool. Thank you!

[@vitvit1250]

thank you very much.. very informative.. it's helping me prepare for an interview

[@koodreitz]

I'm very glad you like my video and that it helps with your work. Good luck with your interview!

[@ife.tugraz]

We are delighted that we could help you with our videos :)

[@huongtran428]

Could you please explain again the statement of " When using spectrum analyzers, the RBW is often defined as the distance after 3 dB", I don't understand clearly about this 3 dB while we are talking about 6 dB of RBW ?

[@fmiyaramusic2462]

I wonder whether the log converter is correctly placed before the detector. I think it should be between the detector and the display. First, the signal after the IF filter is alternating so it has negative half cycles (this could be coped with by rectifying); second, only the peak mode would yield the correct result. Particularly the RMS of a log version of the signal is very different from the log of the RMS value. Third, in several EMI receivers the log/lin graph is optional.

[@ife.tugraz]

We understand your point and do not have a proper answer to your question yet. In literature the setup is often described like we have done it here, but we will try to find out more, why it is done in this way.

[@crazyboy-zq3kl]

How to verify the working of EMI Reciver

[@ife.tugraz]

Unfortunately, we do not fully understand your quesiton. Could you be more precise? Do you have a specific problem?

[@muniappan4430]

Please explain preamplifier

[@ife.tugraz]

A preamplifier is a device (can also be built into the EMI receiver) which features low nois and high gain. It can increase the signal to noise ratio which can be obtained by the EMI receiver.

[@crazyboy-zq3kl]

How to verify EMI Reciver

[@koodreitz]

Could you please be more specific with your question? Unfortunately, I do not understand it.