PCB antenna for nRF24L01P-T

[cristiano23]

Hi ,

few years ago our team has developped a scorer point for tennis based on your nRF24L01P-T (ricever and transmitter). The transmitter is in the player's cuff with a PCB antenna and the receiver was in a metallic enclosure so  

we needed an antenna like a ANT-2.4-WRT-RPS (with RP-SMA connector). We are currently developing a new version with a plastic enclosure and we would like to provide a PCB antenna 
instead of the one indicated before. 
We would need your support to develop this antenna and optimize the performance as much as possible, perhaps maintaining the possibility of also mounting an SMA connector if the performance of the PCB antenna 
should not be enough.

Thanks 

All the best

[cristiano23]

P.S. :Also chip antenna it could be a solution if the performances are better than the PCB one

[ketiljo]

A 1/4 wave PCB antenna, if it's at the correct length, will normally be better than a chip antenna. But the size will be larger. 

Please take a look at this whitepaper as a start: https://infocenter.nordicsemi.com/pdf/nwp_008.pdf

[cristiano23]

Hi Ketiljo, thanks for you answer, in attachment you can see a first draft of PCB antenna, can you give me your opinion about it ?

if we also wanted to insert an SMA connector in parallel how can we proceed? Thanks !

[ketiljo]

Yes, this will be ok. 

You can not use SMA and a PCB antenna at the same time, so you need to switch between them. Use a 0R resistor or a 10 pF capacitor placed in either of two positions to route the signal to the PCB antenna or the SMA connector. Remember to use a 50 ohm transmission line between the cap/resistor and the SMA connector. 

[cristiano23]

Hi ketiljo,  below you can see a draft of PCB Antenna + SMA connector. Please can you give us your opinion? Thanks !