Fleet beacon

The fleet beacon is a protoss advanced building. Easily recognizable, the fleet beacon is built around a huge sphere carved from the largest and purest of khaydarin crystals. The beacon focuses psi through this sphere to strengthen and magnify the warp rift created by the stargate, allowing to teleport the largest of protoss warships (e.g. the carrier). It also provides upgrades to most protoss air units.

StarCraft II
The fleet beacon plays a similar role in StarCraft II. It is a requirement for production of carriers and motherships.

Development
The fleet beacon used to research Apial Sensors (enhanced vision) and Gravitic Thrusters (enhanced speed) for the Phoenix. This has since been canceled.