https://devzone.nordicsemi.com/f/nordic-q-a/59329/nrf24l01-fcc-part-c-band-edge-measurement-failOur product is using NRF24L01+ and PA to transmitter data. It pass all the test of FCC PART C but the BAND Edge measurement. The below 2 pictures is NRF24L01+ Band edge measurement in thelaboratory and in our spectrum analyzer. The RF power of theen-USTelligent Community 13Mon, 23 Mar 2020 11:55:22 GMThttps://devzone.nordicsemi.com/thread/241107?ContentTypeID=1Mon, 23 Mar 2020 11:55:22 GMT137ad170-7792-4731-bb38-c0d22fbe4515:5fee1f89-d467-45ce-a43d-ba27b404df04ketiljo<p>The reason for this is that the skirt of the modulation envelope is too high at the band edge. The only way to handle this is either to lower the output power on the channels near the band edges, or not use these channels at all.&nbsp;</p> <p>There is nothing wrong with the design, it&#39;s just the way the PA work. It will lift the whole spectrum and at some point, you violate the band edge power spec.&nbsp;</p> <p>The main problem is that the nRF24L01+ can&#39;t modulate continuously. When you turn on the PA, you will get a step in power that spreads out in the frequency domain. So the bandwidth of the signal appears to be higher than it actually is.</p><div style="clear:both;"></div>