EEVblog #1273 - EMC Near Field vs Far Field Explained

[EEVblog]

An explanation of near-field vs far-field in relation to EMC compliance testing.
H-field magnetic probes vs e-field electric probes.
Explanation extraction from video #1176
Wideband EMC log-periodic antenna: http://s.click.aliexpress.com/e/DQeIdwZ6
Near field probes: http://s.click.aliexpress.com/e/N5wdxeFQ

[VK3DRB]

Cheaper here... https://www.ebay.com.au/itm/153570679099

$87 Spectrum analyser for the poor man, good enough for use with the near field probes?
https://www.ebay.com.au/itm/Simple-Spectrum-Analyser-D6-with-Trace-Generator-Signals-Ratio-Frequency-Do-K7P3/223621365267?hash=item3410df3e13:g:5AoAAOSwkJxdUbT4

Or a $10 spectrum analyser for the very poor man...

You can also use a good CRO and use FFTs and a wideband RF preamp, instead of a spectrum analyser.

But these days, considering so many products have Bluetooth and/or WiFi, the ideal for many engineers is a spectrum analyser that goes to 3GHz, or better still 6GHz. It is just a matter of time before a NanoVNA equivalent in the form of a decent spectrum analyser becomes available at a fraction of the cost of a traditional spectrum analyser.

[VK3DRB]

Maybe a better deal, inside a case...

https://www.banggood.com/Geekcreit-Spectrum-Analyzer-USB-LTDZ-35-4400M-Signal-Source-with-Tracking-Source-Module-RF-Frequency-Domain-Analysis-Tool-With-Aluminum-Shell-p-1494125.html?cur_warehouse=CN

[VK3DRB]

You can also build your own near field test probes... https://interferencetechnology.com/diy-near-field-probes-preamplifiers/

[ocw]

The Seeed 114990711 / RFEAH-25 20 - 6000 MHz magnetic field probe is just $27.50 at Mouser.
See: http://statics3.seeedstudio.com/assets/file/bazaar/product/RFExplorerRFEAH_25datasheet.pdf

[arildj78]

@EEVBlog, are you still planning to show a DIY solution for far field measurements? So far I've seen some content on near field EMC pre compliance but DIY solutions to far field measurements are rare.

[EEVblog]

@EEVBlog, are you still planning to show a DIY solution for far field measurements? So far I've seen some content on near field EMC pre compliance but DIY solutions to far field measurements are rare.

No plans, but possible. I have a couple of far field antenna.

[arildj78]

@EEVBlog, do you care to revisit this? I´m still waiting for content on DIY far field measurements and how to approach the jungle of compliance as a maker.

[EEVblog]

Did you post this twice?
I'm not sure, as I got a database error when posting my previous reply, just want to ensure something weird is not happening?

[nctnico]

@EEVBlog, are you still planning to show a DIY solution for far field measurements? So far I've seen some content on near field EMC pre compliance but DIY solutions to far field measurements are rare.

Stay tuned....

[arildj78]

No, I didn't post twice, but I did revive an old post.

Arild