Phase Array Radar
Understanding Phased Array Radar
Phased array radar represents the most advanced radar technology in operation today. By eliminating mechanical scanning, PARs achieve scan rates and flexibility impossible with rotating antennas. They are essential for air defense, missile defense, weather monitoring, and air traffic control.
PAR Types
- PESA (Passive ESA): Single transmitter, phase shifters at each element. Simple but limited flexibility.
- AESA (Active ESA): T/R module at each element. Maximum flexibility, graceful degradation, multiple simultaneous beams. Dominant modern type.
PAR Advantages
- Scan speed: Microsecond beam repositioning vs seconds for mechanical rotation.
- Multi-function: Simultaneous search, track, and missile guidance on different beams.
- Reliability: AESA continues operating with some failed elements (graceful degradation).
- Low observability: Frequency agility and low sidelobes reduce detection by ESM.
Frequently Asked Questions
What is a phased array radar?
A PAR uses an antenna array with electronic beam steering for target detection and tracking without mechanical rotation. It can scan in microseconds, track hundreds of targets simultaneously, and adapt its beam pattern in real-time.
What is AESA vs PESA?
PESA uses one transmitter with phase shifters at each element. AESA has a T/R module at every element (each with its own transmitter and receiver). AESA provides maximum flexibility, higher reliability, and multiple simultaneous beams.
What are examples of phased array radars?
Military: AN/SPY-6 (Navy ship defense, AESA), AN/APG-81 (F-35 fighter, AESA), THAAD radar (missile defense). Civil: Nextrad (weather, PESA), airport surveillance. Space: Starlink ground terminals (flat-panel AESA).