• State Verified Answer
  • Replies 6 replies
  • Subscribers 64 subscribers
  • Views 4737 views
  • Users 0 members are here
Attachments (0)
Nordic Case Info
  • Case ID: 116385
Options
This post is older than 2 years and might not be relevant anymore
More Info: Consider searching for newer posts

nRF52 antenna connection and shielding

NewtoM

Dear All,

we have been working on a very small PCB design using nRF52832. Some time ago, in another thread, I asked for an Eagle footprint for an antenna and got the quick answer (thanks again!) that it's available on GitHub and there's also information on how to connect it to the chip.

For the meantime we have bought some of the IMM-nRF52 PCBs for testing and they also use the smaller antenna footprint, which we plan to use in our design.

We noted that one end of the antenna in the IMM-nRF52 is connected to the shielding, which is grounded, see picture below.

image description

This kind of confuses me. So here are my questions:

  • Do we really need to ground one end of the antenna (this was not to be seen in the Eagle footprint provided on GitHub)?

  • (When) do we need to use metal shielding like the IMM-nRF52 does? (The nRF52 DK does not haveshielding and still works well...)

I would be very grateful if someone could answer my above questions.

Thanks in advance, NewtoM

Parents
  • 0

    Hi,

    • The antenna on this module is an inverted F antenna (or more specific a “meandered inverted F antenna"). Inverted F antennas are grounded at one end as can be read in the Wikipedia article.
    • You probably don’t need shielding. Pre certified modules must have shielding. This is because the FCC requires shielding on a module that is being sold with the FCC number already in place.

    Best regards
    Ole

  • 0 in reply to Ole Bauck

    You can use that antenna yes, but be sure to know how to use it first. From the picture it looks like the antenna is connected the wrong way. It is also important that the antenna is the same distance from the ground plane as the antenna in the library. You should see how it is done on the nRF51 dongle.

    I also see that you have not followed the reference design. It is important that you do this. The paths between the antenna and the chip should not go through vias and you should not have any other tracks going under (or over) the matching network. Please take a look at this blogpost and when you are finished with your design send it to us for evaluation.

Reply
  • 0 in reply to Ole Bauck

    You can use that antenna yes, but be sure to know how to use it first. From the picture it looks like the antenna is connected the wrong way. It is also important that the antenna is the same distance from the ground plane as the antenna in the library. You should see how it is done on the nRF51 dongle.

    I also see that you have not followed the reference design. It is important that you do this. The paths between the antenna and the chip should not go through vias and you should not have any other tracks going under (or over) the matching network. Please take a look at this blogpost and when you are finished with your design send it to us for evaluation.

Children
No Data
Related