External SMA Antenna on nRF52840 DK

[Valentin]

Hello,

I would like to test performance between onboard antenna and an external antenna connecting to the SWF type connector MM8130-2600.

I bought the test probe MXHS83QE3000 and I connect a 2.4GHz antenna to the nrf52840 DK :

I have a thread network with a router and a child with the external antenna above. My purpose is to test the longrange and if the external antenna increase the range.

Unfortunately, I see no difference between the external antenna plugged and the onboard antenna during my tests. The child lose the connection at the same range.

I'm asking if there is a performance increase with an external antenna ?!

How increase the RF signal for long range mode on nRF52840 DK Board ?

Valentin

[ketiljo]

If the external antenna you have doesn't have more gain than the PCB antenna, you won't see any increase in range. Even if the antenna appears to be longer, it's not necessarily better. 

The antenna should perform better if you use it with a ground plane. Try mounting the SMA connector in a metal plate and see if that makes any difference. 

[Valentin]

Thanks you for your response, we have tried this :

And it's better, we have increase the range about 30m ! We will do a better ground plane, thanks you.

Have you any ressources to calculate the size of the ground plane for an antenna please ?

[ketiljo]

As large as practically possible is the best. Do some experiments and see how small you can make it before the range starts to drop. Less than 1/4 wavelength in radius will have impact on the range. 

[Victor Ruiz 26]

Hi Valentin,

Where did you buy that cable? I am searching for it in many websites but I do not find the same...

Thanks in advance!

[mej7000]

I just happened to be searching for the same information. I think this is the cable in question: ‎MXHS83QE3000‎