How to make AWUS1900 work in Kali, Debian or Ubuntu?
22/04/2018To make this amazing usb wifi card work, just install the following driver:
sudo apt-get install linux-headers-`uname -r`
sudo apt-get install dkms
sudo apt-get install realtek-rtl88xxau-dkms
reboot
Sources:
https://forums.kali.org/showthread.php?36296-EXTREME-WIFI-SUPPORT-Alfa-Networks-AWUS1900-WORKING
https://underc0de.org/foro/dudas-generales-121/(solucionado)-alfa-awus1900/
Edit 2025: updated wayaround to install this driver and make it work at Virtualbox: https://bytebreach.com/posts/alfa-kali/
Desarrollo Linux y software libre 
The package realtek-rtl88xxau-dkms is not available in Debian repositories.