How to measure the GSM 900band signal

I am currently conducting a test on the WP7702 module, measuring the output signal spectrum of the WP7702 in the GSM 900MHz band. The issue I am encountering is the presence of a significant harmonic at the frequency of 1800MHz, which poses a problem for European certification. I wish to determine whether this harmonic is originating from an error in my PCB design or from the module itself. I conducted the same test on the MangOH Yellow platform where the same module, WP7702, is present, and the harmonic was also present on the MangOH Yellow. Therefore, if you have any suggestions on how to reduce this harmonic, I would greatly appreciate

Hi @bilal.kassem,

Currently, there is no official documentation on the source page guiding how to minimize harmonic. In this case, it is best to send an email to technical support at for further assistance.