The antenna stub?

Hi, I don’t know what the antenna stub do? Who can tell me? thanks!

Hi there,

This antenna stub forms part of the antenna. Without it, the performance would probably be worse. You should include this stub copper in your PCB layout as part of the component footprint.

Thank you very much! :smiley:

Also keep in mind that the board layout given in the datasheet is for a 2 layer 1 mm thick PCB. If your PCB is a different thickness or stackup then you need to change the track width or spacing to maintain 50 ohms impedance.
e.g. for a 1.6 mm thick PCB (the standard thickness) if you want to keep the signal trace as 1 mm wide then the space between the antenna input trace and ground plane should be decreased from 0.2 to 0.15 mm

Thank you for your help!