Forum Post: CC1101/CC1190 EMK Reference design update for 915 MHz

Hi Support,

We are having RF-compliance issues with our product incorporating the CC1101/CC1190 EMK reference design used in the 915MHz ISM band. In short, our 2nd harmonic is violating the FCC limit by a considerable margin.

I noted that rev 2.1 of the 869MHz ref design has a LC-notch filter directly attached to the CC1190 output to attenuate the 2nd harmonic. Can we add a similar notch filter to our 915MHz design to combat our 2nd harmonic problem?

Is the reason this hasn't been added to TI's reference design purely because it already complies with FCC Part 15? Presumably some improvements to the 915MHz ref design could be achieved if it were?

Thanks in advance,

Hayden