https://devzone.nordicsemi.com/f/nordic-q-a/14606/basing-my-design-on-pca10028-do-i-need-to-include-both-c6-and-c15I&#39;m basing my schematic and antenna design using the PCA10028 as a reference. I&#39;m not including the J1 RF-connector into my design. Do I still need to include both C6 and C15? In the nRF51822 Product Specification there is only one 1.5pF capacitoren-USTelligent Community 13Mon, 20 Jun 2016 08:57:24 GMThttps://devzone.nordicsemi.com/thread/55739?ContentTypeID=1Mon, 20 Jun 2016 08:57:24 GMT137ad170-7792-4731-bb38-c0d22fbe4515:d48b85f8-ba8e-4221-a376-59683f55b4cc&#216;yvind Karlsen<p>Hi,</p> <p>Have a look at the <a href="https://devzone.nordicsemi.com/tutorials/25/">general PCB design guidelines for nRF51</a>. C15 is part of the antenna circuit, the antenna structure is matched to 50 Ohms using a PI network. In the case of a quarter wave printed monopole the PI network can be simplified by shortening the antenna until it reaches the desired impedance (G=1 circle in the smith chart), then removing the inductance by adding a shunt capacitor, seen by C15 on PCA10028.</p> <p>C6 is part of the output match for the nRF51822 and must be included.</p> <p>Best regards,</p> <p>Øyvind</p><div style="clear:both;"></div>