Once fired, these missiles will locate and track toward the nearest airborne target and explode within close proximity."
— In-Game Description
Active Radar is a vehicle specialization for Mobile Anti-Airs and stealth jets featured in Battlefield 4. It provides the player with a dumb-fire missile that will automatically guide itself toward nearby enemy aircraft. The only thing the player needs to do is to lead the target properly; the Active Radar missile will not guide itself if the target is too far away from player's aiming point.
The operator does not need to maintain weapon lock on the enemy aircraft. An enemy will be unaware of the missile until the last moment, as there are no lock warning until the missile is very close. This is similar to the scheme for the STAFF Shell for the MBT and the MBT-LAW used by Engineers.