Você pode definir isso permanentemente, executando no terminal
sudo tee /etc/modprobe.d/rtl8723be.conf <<< "options rtl8723be ant_sel=1"
koolhussain@koolhussain-Notebook:~$ modinfo -p rtl8723be
swenc:Set to 1 for software crypto (default 0)
(bool)
ips:Set to 0 to not use link power save (default 1)
(bool)
swlps:Set to 1 to use SW control power save (default 0)
(bool)
fwlps:Set to 1 to use FW control power save (default 1)
(bool)
msi:Set to 1 to use MSI interrupts mode (default 0)
(bool)
debug:Set debug level (0-5) (default 0) (int)
disable_watchdog:Set to 1 to disable the watchdog (default 0)
(bool)
ant_sel:Set to 1 or 2 to force antenna number (default 0)
(int)
koolhussain@koolhussain-Notebook:~$ sudo modprobe -r rtl8723be
[sudo] password for koolhussain:
koolhussain@koolhussain-Notebook:~$ sudo modprobe rtl8723be ant_sel=1
koolhussain@koolhussain-Notebook:~$
Você pode definir isso permanentemente, executando no terminal
sudo tee /etc/modprobe.d/rtl8723be.conf <<< "options rtl8723be ant_sel=1"