
DIY Wi‑Fi Reflector: Foil Behind the Router Focuses Signals—With Important Tradeoffs
A Dartmouth study showed curved, precision-shaped aluminum reflectors can steer Wi‑Fi and boost signal in a specific direction by up to about 50%, but DIY foil behind a router yields smaller gains (roughly 10–20%) and concentrates existing power rather than increasing total output. It can cause overheating and is not a substitute for proper router placement, extenders, or mesh systems; regulatory limits mean this is a temporary, directional tweak rather than a fix-all.


