EG91 spurious problem

I’m having spurious problems on the EG91 moduel , especially when using GSM900.
The spurious i have is the 2nd harmonic (1800 MHz).
Do you have any idea to supress this suprious ? actually my product doesn’t pass the certification !
Thank you

Dear Ahjaouadi,
Thanks for your inquiry in Quectel forum.
You mean the module have such 2nd harmonic problem ?
If you can confirm it is the module issue, please help to provide more information, and our module have passed many certifications. And could you tell us what certification you are pass now ? Thanks!

Thank you kyson for your answer ,

Ok let me explain : we are doing a radiated transmission test. The spurious level should be less than -30 dBm.
On our device, the radiated spurious is around -30dBm (more or less , depending on the sample).
I have tried a conducted mesurement with a dev board + EG91-E module.

On our setting , we are using a 30dB attenuator + 1dB of path loss. We also have a high pass filter to supress the 33dBm GSM900 signal. As you can see on the photo below , the H2 level is quit high (-61.89 + -31 = -30.89 dBm) .

If i could reduce the conducted spurious , it would reduce the radiated spurious probably too.
Do you have any recommandations to reduce it ?

Dear Ahjaouadi,
Thanks for your updating.
How about the test results with dev board +EG91E module ? The test results still cannot pass the certification ?
If it is failed on conducted spurious, it is better to confirm whether the test environment is correct, whether there have any interference on your main board.
And about your issue, we may need to check it on site. Please email to to get the local support. Thanks!

This result is with the dev board .
It actually passes the certification, but with 1db of margin, which is quite low and risky.


If it can pass the certification, it may have no problem. We will try to improve and optimize the RF performance. If the module have any issue, you can contact us or email to to get local support. Thanks!