ST25R95 EMC 3rd and 7th harmonic failed

[JECKSON]

Hi ST members

I am using the ST25R95, following the application note and matching tool to define LC components for EMC filter and matching circuit. the function test is good, but I have a high pulse at 3rd harmonics 40.8MHz and 7th 94.92MHz, do you have similar case happens with emission issue? 

have any suggestion？

thanks！

[Travis Palmer]

Hello Jeckson,

In general it could be that a ESD diode is saturated and cuts off/limits the sine wave. I would like to ask you to check all the voltages, if they are inline with the datasheet specification.

Could you also share the layout related to the NFC part.

It would also be interesting, if you change supply filtering what the resulting change in the spectrum would be.

BR Travis

[JECKSON]

Hi Travis

Thanks for your help！

I will check all voltage tomorrow， please check my layout first