RE: Layout review of Meandering Antenna

Øyvind Karlsen — Wed, 24 Jun 2015 06:55:41 GMT

Hi,

The nRF51 dongle uses a meander antenna, it's reference design files can be found here. The reference designs are good, so they should be followed when possible. I'd also recommend reading this blog post on General PCB design guidelines for nRF51.

As for your questions:

Yes, ground plane should be pulled back from the RF components due to unwanted parasitic effects(e.g. stray capacitance) to ground. For an indication of how much, please see the reference design files.
16MHz looks fine

The SWCLK and SWDIO(pin 23 and 24) should be kept away from the antenna an RF parts. Make sure to ground C4 thoroughly. It's hard to see from your file if the tap of your antenna is grounded or not(no visible vias), it should be grounded.

Another note is that when you upload your layout it is a lot easier to see what's going on if you include vias. If possible upload full design files.

Best regards,

Øyvind