https://devzone.nordicsemi.com/f/nordic-q-a/60863/nrf52840-rf-ground-ckaa-vs-qiaaHello, There is a comment in the v1.1 manual (shown below) which states that the first capacitor in the matching network (C3 in the reference designs) shouldn&#39;t be connected directly to ground, but that it should be grounded through the VSS_PA pinen-USTelligent Community 13Thu, 30 Apr 2020 08:43:30 GMThttps://devzone.nordicsemi.com/thread/247478?ContentTypeID=1Thu, 30 Apr 2020 08:43:30 GMT137ad170-7792-4731-bb38-c0d22fbe4515:6ef1b39a-3424-4650-adf4-0a7db7b8e213ketiljo<p>The layout and the components values of the matching networks for the various devices and packet variants are all optimized for that specific part. So always use the&nbsp; layout and component values that can be found in the reference layouts.&nbsp;</p> <p>For the CIAA packet, there&#39;s no benefit to change the grounding of the capacitor. You risk making it worse. If you fail the regulatory testing, you must ask for a review if your design, all reference designs are tested and will comply if done correcly.</p><div style="clear:both;"></div>