need to strengthen wifi signal?

I had the very same issue, my house is very old and has thick stone walls which killed the wifi signal, I bought a TP-Link powerline wifi kit which consists of two plugs, one that connects to the router via an ethenet cable and just plugs into a power outlet then the other one you plug into a power outlet in the low signal area, the signal then travels through the house wiring and out of the plug, the signal strength where the plug is is now as good as being next to the router.

You can get a booster or a repeater. Something you can try before spending money, try using some heavy foil as a mirror. Put the foil or even a mirror on the side away from where you want the signal to go ...

You can also look in the router software to see if there is a power setting, in which case you might be able to increase the power level. If your router software doesn't have such a setting, you could upgrade your router with the DD-WRT or Tomato firmware which do offer such a power setting.

Your existing router sounds find but in case if it is still not fulfilling your needs then I would suggest to go for an extra WiFi repeater. This shall not only boost your signal but will also increase your coverage are in order to have better signal strength. Good Luck

Raise your wi-fi router so it is at least three feet above floor level.

maybe just get a new router