No WiFi adapter found in Ubuntu 18.04


 When you install Ubuntu 18.04 on your system, you may notice your wifi network is not found. To resolve this follow below steps:

Step 1: Connect your system with wifi adapter(external data card)/network cable

Step 2: Execute below commands

$ sudo apt remove bcmwl-kernel-source && sudo apt install git dkms
$ git clone -b extended
$ sudo dkms add ./rtlwifi_new
$ sudo dkms install rtlwifi-new/0.6
$ sudo modprobe -r rtl8723de && sleep 5 && sudo modprobe rtl8723de ant_sel=1