NFC Antenna's Waves were not fluently

[chenyuxiang]

Hi  Supporters:

    I used the St25r3911b IC to design NFC Module. Then, the new module could work.
    However, the waves at the Antenna side are not well, please check the picture at the end.
    I think maybe the matching circuit parameters do not match antenna? Please help me, thanks!

[Ulysses HERNIOSUS · Accepted solution]

Hi,

hard to judge but it seems more like a 50Hz signal (from the mains) being superimposed here. Maybe through the supply or on the antenna or probe lines. Is that a lab supply next to the scope?

On a first glimpse likely more a measurement setup issue. Please try to vary that and analyze in more detail.

If not solved by this hints: Please share pictures of the complete setup, antenna, matching, etc....

Regards, Ulysses