Hi @kas_boot ,
Not sure but [https://www.ebay.com/itm/Genuine-Samsung-Galaxy-A5-2017-A520-Main-Antenna-Intenna-GH42-05890A-/401268089003|this] is either the GSM antenna or the WiFi antenna (supplier example only to show what it looks like).
The part number is ''GH42-05890A''.
The part location can be seen ~3:00 minutes into this [https://www.youtube.com/watch?v=t06_rLWAZTM|video].
Hopefully this is of some help.