RE: Which Antennae to use with nRF 8001

Vincent — Thu, 01 May 2014 08:41:21 GMT

Hi Ole,

I'm in the same situation as above, going to receive my prototype with a PCB antenna soon. What do you mean exactly by "tuning is something we can help you with"?

Do you have simulation tools to tune PCB antennas or do you mean testing a prototype?

Can I find somewhere the exact gerbers and parts of the design you've used in your dev board or is this something you don't provide? I had nRF2728 dev kits back in the day and I still have the gerbers Nordic provided. On a previous design I rigorously copied that and it worked like a charm!

Just the matching circuitry is unlikely to work with 8001.

Thanks, Vincent

RE: Which Antennae to use with nRF 8001

Ole Morten — Thu, 13 Feb 2014 16:40:21 GMT

You can use any 50 ohm antenna with the nRF8001, either a simple PCB trace of some kind or a chip antenna.

Between the nRF8001 and the antenna, you first need to have either the matching network shown in the PS or a balun, and after this, some compontents for antenna tuning. The matching network or balun converts the output impedance of the chip to a single ended 50 ohm point, while the antenna tuning compontents are used to tune the antenna used to actually have 50 ohm impedance. For a chip antenna or meander antenna, a full pi-network is recommended, while for a simple trace antenna, a single shunt capacitor is usually sufficient, since the length of the antenna can also be adjusted.

It's impossible to say which values should be used for the pi-network or the shunt capacitor without testing, but such testing is something we can help you with, as long as you've had the design reviewed first. If you need such review, please create a regular support case, and upload your complete design (schematics and Gerbers/Altium files) there.