Wi-Fi speed on my laptop with RTL8723DE is a bit slow and its range is also very low, what to do?
Solution 1:
Quite often, the weak signal is a symptom of the antenna wire being connected to connection #1 on the card when the default driver is expecting to see the signal at connection #2. Of course, you could open the laptop and switch the wire or you could try a driver parameter that permits antenna selection at the driver level.
From the terminal:
sudo modprobe -r rtl8723de
sudo modprobe rtl8723de ant_sel=2
Any improvement? If so, we'll write one conf file and make it permanent.
If there is no improvement, try the sequence again with ant_sel=1
and report the result.
EDIT: Since you have determined that 2 is helpful, create a file that will make the parameter permanent:
sudo -i
echo "options rtl8723de ant_sel=2" > /etc/modprobe.d/rtl8723de.conf
exit
You should be all set.