My printer sometimes disconnects from my wifi and has a general bad connection due to the distance to my access point. I wanted an easy way to improve the RF performance of the prusa wifi module, because other smart Home stuff works at this distance. I found an blog article to add a wire antenna to an esp32. The wire antenna is glued on top of the integrated PCB antenna and is coupled by inductance and capacitance. 

The wire should be 58mm long with a solid core 0.5mm in diameter. 

Just follow the pictures or read the blog article. Performance gain is about +4dB

I also added wifi performance pictures before and after the upgrade. After the upgrade there was not one disconnect from my access point. 

Blog article: https://peterneufeld.wordpress.com/2021/10/14/esp32-range-extender-antenna-modification/