https://devzone.nordicsemi.com/f/nordic-q-a/15724/layout-design-using-smd-antennaHello I am doing a PCB design using nRF51422-QFAC chip. I did based on nRF51-DK but now I would like to change for a SMD antenna (2450AT18A100 from Johanson Tech.) instead of a microstrip antenna type. I am sending two screenshots, one is the schematicen-USTelligent Community 13Mon, 15 Aug 2016 09:30:26 GMThttps://devzone.nordicsemi.com/thread/60013?ContentTypeID=1Mon, 15 Aug 2016 09:30:26 GMT137ad170-7792-4731-bb38-c0d22fbe4515:e4068b6a-ecd6-4473-b13e-6982667733baH&#229;kon Alseth<p>Hi,</p> <ol> <li> <p>integrated BALUNs are often used for space concerns and ease-of-development (1 component vs. 6). If you follow the reference schematic and layout, the performance is more or less equal in both scenarios.</p> </li> <li> <p>As @Dave_couling says; you will need an <a href="https://en.wikipedia.org/wiki/Antenna_tuner#.CE.A0_network">antenna tuner (pi-network)</a> between the BALUN output and the antenna input. Other than that, it looks to be in order.</p> </li> </ol> <p>Cheers, Håkon</p><div style="clear:both;"></div>https://devzone.nordicsemi.com/thread/60012?ContentTypeID=1Sat, 13 Aug 2016 02:26:55 GMT137ad170-7792-4731-bb38-c0d22fbe4515:f3454ff7-2161-42c5-9b3b-2762781b08c1Dave_couling<ol> <li> <p>You have a discrete balun insteads of a chip balun. Discrete baluns are sensitive to tune, whereas chip Baluns are already done. But they will have greater insertion loss.</p> </li> <li> <p>You need to have a T or Pi network in series with the antenna to tune with a Network Analyzer.</p> </li> </ol><div style="clear:both;"></div>