Introduction: EMC - Radiated Emissions Tool Sensor

You ever needed to know EMC (electro magnetic compability) performance of your PCB design or just to know oscillation, radiated emissions of it? Here is a great homemade tool and sensor.

All you need is oscilloscope and some wireless charger. If you don't have charger you can just use some isolated copper wire, double sided ducktape and do inductor by yourself.


- Oscilloscope is first thing what you need. If you don't have it or can't afford proper one, you can find a lot of DIY kits on aliexpress,ebay etc. Or even mini oscilloscopes which work very great.

I have this one and is super ->Mini DSO

- Wireless charger - I used this because it was useless for my phone. If you have any of copper wire you can do it by yourself as you wish to have it.

Step 1: Wireless Charger

Design is simple!


1. Just take your wireless charger,

2. Open it,

3. Desolder all electronics

4. You will have only inductor with two wires, on each wire you solder longer wires and put them out of the housing.

5. Connect probes to oscilloscope and to this two wires and you are ready to go for measurements!


If you don't have any wireless charger but you have isolated copper wire:

1. Prepare doublesided ducktape and put it on flat surface

2. Take you wire and start creating circles, wires needs to be close to each other.

3. When you are finished, place ducktape on other side so it will be like in "sandwich"

4. Connect it to probe and oscilloscope and thats it!

Step 2: Measurement on PCB

Measurement was performed on PCB which was placed on so called EMC radiated emissions sensor.

You can see on pictures FFT measurement and voltage in case when PCB is OFF and in case when PCB is ON (supply on). On Oscilloscope can be seen that oscillation is present around 150Mhz in FFT mode measurement. If you are measuring only votlage you can see how signal rise all over the screen, if there is no emissions/oscillations signal must remain the same.

Thanks for reading and vote for contest please :)

P.S. PCB is blurred, due to customer policy.


drejcekster (author)2017-02-01