You need to educate yourself on mesh wifi systems or distributed wifi systems.  I'm partial to Unifi wireless because it is not difficult to setup and not expensive in the realm of commercial wireless products.  A single antenna will not do what you want for several reasons but the biggest is that smaller radios (phones, laptops, etc) are not powerful enough to send data back to the large radio.  They will probably see the signal but not actually be able to talk to it.  Newer, faster frequencies also have less ability to penetrate trees, walls, buildings, etc.

If you attempt to do something yourself you'll need to decide if you want point to point links between buildings with access points in each building or a complete mesh system.  Each has its own advantages and disadvantages but both will allow you to have a single SSID/password that your devices connect to seamlessly.