This paper presents an evolvable antenna architecture which allows the radiation pattern and gain of the antenna to be adapted in real time. The antenna can be implemented at a much lower cost than traditional antenna arrays, is simpler to construct, and is very robust. The architecture is also highly amenable to closed-loop control techniques that interface directly with the antenna hardware. A control scheme known as self-phasing was implemented using evolutionary algorithms and integrated with the antenna hardware. It enables the antenna to lock onto and track changes in incoming signal without any prior knowledge of the transmitter's location. It can also automatically reconfigure the antenna hardware to deal with environmental effects and faults in the array hardware. The design of a medium scale evolvable antenna system prototype is presented along with experimental results illustrating the retro-reflection capabilities of the antenna and controller.