Can I enhance Wi-Fi with a parabolic reflector?
Maybe, but there are lots of details about digital signal processing that are more complicated than just using a reflector.
Luckily, one of them is a simple off-the-shelf solution: your antenna. Most consumer wifi equipment uses an omni-directional antenna, so it can receive and send in any direction. For a fixed power you can imagine that some of your signal goes off in a direction you don't care about.
Instead your could try directional antennas (which may include a dish) and point then directly at their stationary target. A web search for &quot;directional wifi antenna&quot; will get you started.