Inquiry regarding RF line extension for nRF52810 Central implementation

[paul0208]

Hello,

I am currently implementing a Central device using the nRF52810 as part of a Gateway board.

I intend to connect the antenna via a U.FL connector. My current design strictly follows Nordic’s reference design. Additionally, I have incorporated a GND shield pattern to allow for the installation of a Shield CAN in the future.

I would like to place the crystal (X51) inside the Shield CAN as well; however, the RF line in the reference design is quite short. Since I am using a 2-layer PCB and the RF line width/spacing follows the reference design, I am concerned about extending it.

If I need to lengthen the RF line, what is the best approach? Should I implement an additional pi-network for matching, or are there other layout considerations I should follow?

[paul0208]

I've revised the layout by adding an external Pi-matching circuit outside the shield CAN. I'm currently using a $0\Omega$ jumper for the series component (L) to test the initial RF performance.

[JONATHAN LL]

Looks mostly good. 
Schemtic is ok. 

Adding the extra pi is nice to have, you can leave the two caps N.C and have a 0 ohm series resitor. 


I would add some extra vias around the areas where a marked here, always better to have good GND connection. 

Also along the RF path I would add vias that tie the ground planes together. 


The C62 component can be removed if you want. So you dont need to have the footprint in the layout. 

Looks ok. 

Regards,
Jonathan

[paul0208]

L52 will be 0 ohm resisteor and C63, C64 is not equiped at first.
I add vias... as you suggest.

RF path width is 0.762mm which is same from reference design of yours.
Is it OK?

BR
Paul 

[JONATHAN LL]

Looks good Paul, nice work. 

Regards,
Jonathan