https://devzone.nordicsemi.com/f/nordic-q-a/7411/custom-board-designHello, I was reading about RF design and some articles say that if the transmission line is short enough, you may not consider impedance-control as the effect is not visible. On my design, I have the nRF51422, a BALUN (Johanson) and a chip antennaen-USTelligent Community 13Thu, 04 Jun 2015 15:54:45 GMThttps://devzone.nordicsemi.com/thread/26361?ContentTypeID=1Thu, 04 Jun 2015 15:54:45 GMT137ad170-7792-4731-bb38-c0d22fbe4515:93e1d899-2aa5-4742-a067-d96e70cac248Hung Bui<p>@Vitor: You may get away with the parasitics on the short transmission line, but there are other factors may affect the impedance which is the ground plane, PCB material, housing of the device.</p> <p>If you just want to have a prototype that works you are fine to have just the balun and the chip antenna with OK RF performance. If you want to optimize the performance a PI tuning network is recommended.</p> <p>Note: we offer free antenna tuning service, you just have to send us your board and housing for tuning.</p><div style="clear:both;"></div>