https://devzone.nordicsemi.com/f/nordic-q-a/25844/nrf51822-beacon-pcb-stackup-2-layer-requiredHi, We are designed our own Beacon PCB based on nRF51822 Beacon Kit...We followed board size,PCB Antenna Trace width and GND Clearance as per Beacon kit...The difference is NRF51 Package we followed QFN instead of BGA... We have to include FAB detailsen-USTelligent Community 13Thu, 12 Oct 2017 09:09:37 GMThttps://devzone.nordicsemi.com/thread/101796?ContentTypeID=1Thu, 12 Oct 2017 09:09:37 GMT137ad170-7792-4731-bb38-c0d22fbe4515:6a5e1fbf-bc62-40f0-afdc-80d2aca968d0MartinBL<p>Hi,</p> <p>If you have access to Altium or Altium Viewer you can get an overview of the stackup used on the beacon. If you have purchased an nRF51822 Beacon kit and own a key you can find Beacon HW files <a href="https://www.nordicsemi.com/eng/Products/Bluetooth-low-energy/nRF51822-Bluetooth-Smart-Beacon-Kit/(language)/eng-GB">here</a>. This is the beacon stackup:</p> <p><img src="https://devzone.nordicsemi.com/cfs-file/__key/communityserver-discussions-components-files/4/5C4C28C1.PNG" alt="adsfkh" /></p> <p>Regarding the 50 Ohm impedance you can try to copy our reference design as closely as possible, but to achieve optimum performance you <em>will</em> have to tune the antenna. In antenna and high frequency designs, tiny differences in the layout can have huge effects on the impedance. If you have your device placed in a casing you will also have to compensate for that and tune the antenna with the device installed in the casing.</p> <p>Nordic can help you out with tuning.</p><div style="clear:both;"></div>