"Drawing" signals with antenna
The idea you are referring to is know as beam forming. Some high end WiFi routers have been using it for several years now. The idea is by transmitting the same signal from multiple antennas (usually 4) and imposing different delays on 3 of them the signal forms paths of interference. Some being destructive and some being constructive. By pointing a channel of constructive interference in the direction of a client (a laptop for example) the signal strength is boosted in that direction.