If you use this cone in the above post, you can then redirect it using double slits(young's experiment). The slits being half the wavelength(3 cm in the case of 5GHz). You will then get 3 or more "beams" in 3 or more directions(see young's experiment) at the cost of signal strength. You can then block the beams you do not want "go on" with and continue directing the waves is this way to your desired location. it would be kind of like using a cable(a bad cable at that) though, but still, it would be kinda cool. You could allso use reflectors for the same purpose, but then you would get a wider "beam". It would be kinda like a laser beam with mirrors, but in this case where you have a cone to direct the beam, it would be more like a flashlight with mirrors. Don't know if this can have any practical application, but its a fun thought experiment

btw, you can reduce the signal strength with various materials, like solid plastic. Depending on the material and how you place it you can also cut off the signal in some directions(EM-waves travel faster in air than in most materials, so if you cover half the "beam" you have, with the right material and right thickness, you will get destructive interference at the receiver). Might be too far in to the realm of physics, but it should work
