nRF52832 antenna files

[Lalit Kumar Baghel]

I am using Meander line inverted F antenna for beacon and development board based on nRF52832.

Is it okay to go with this antenna or shall i change this antenna.?

Where can i get the dxf files of antenna used in Nordic dev kits.?

[Andreas]

Hi,

 

Hard to say without actually seeing the antenna, could you show an image or something?

 

We do not provide dxf files, you can find Altium files, gerbers and PDF images of the DK here: https://www.nordicsemi.com/Software-and-tools/Development-Kits/nRF52-DK/Download#infotabs

 

Best regards,

Andreas

[Lalit Kumar Baghel]

Please find the attached gerber files and please check antenna as well.nRF52832 Beacon (2).zip

[Andreas]

Hi,

 

The antenna design is fine, but I have some other comments to your design:

• You need more vias across the ground planes and in the center pad of the nRF.
• The part underneath (in the bottom layer) the RF components must be solid ground
  
• C10 shall only be grounded into the center pad through pin 31, like in our reference layout:
  
  Also note the keepout around L1 (L3 in your design)
• Add/extend a ground pour here with a couple vias:
  
• You need to add two more components for tuning the antenna, a series component and another shunt component between C11 and the antenna (making a pi filter along with C11).

 

Best regards,

Andreas

[Lalit Kumar Baghel]

Thank you Andreas for your quick response.

I have got all the points, except the last point i.e., about pi filter.

How shall i choose the value of shunt and series capacitor, in order to make pi filter with C11 ?

[Lalit Kumar Baghel]

and how should i ground the antenna terminal?

[Andreas]

Hi,

 

The pi filter components must be determined through tuning the antenna, see this whitepaper: https://infocenter.nordicsemi.com/pdf/nwp_017.pdf?cp=16_14

As start values you can just DNP the shunt components and 0 Ohm the series component. The antenna will work to some degree, but not optimally until tuned.

 

As for the grounding you should replicate as close as possible to the reference you have used. For this antenna I believe it should just be connected to a solid ground plane.

 

Best regards,

Andreas

[Lalit Kumar Baghel]

Hi,

Ground plane for this antenna do have some specific ground plane dimensions or i just connect it simply to ground plane?

[Andreas]

Hi,

 

The part near the feed and the ground arm should be a flat continuation of the uppermost edge in your design:

Whether or not you decide to have the current edge (like the yellow line) or continue this edge straight down (like the red line) probably does not matter all that much. Up to you.

 

Best regards,

Andreas