High power tube-driven Mechanically Scanned Antenna (MESA) RADARs ruled the skies for decades. They were the backbone of the weapon systems on board the F-16, F-15, F-18, and were produced by the thousands. But where have they gone and why? Have Actively and Passively Scanned Electronic Array (A/PESA) RADARs forced the MESA RADARs the way of the 8 track and VHS tape? Or are MESA RADARs ready for a renaissance in Western North Carolina?
Duotech Services, Inc., based in Franklin, NC, and the DELTA and NEMESIS RADARs are taking mechanically scanned systems to the next level. Whereas the AN/APG-66 / 68 / 70 / 73 leaned on cutting-edge signal processing technology pioneered in the 1970s and 1980s and largely relied on much older technology in the form of tube-based transmitters (circa 1940’s), the DELTA and NEMESIS RADARs employ modern signal processing techniques combined with start-of-the-art solid-state transmitters. While keeping the same aperture of one of the aforementioned RADAR’s flat plate antennas, but utilizing Duotech’s modern techniques for RF power amplification and signal processing, the range of the RADAR can double. With fewer up/down conversions as well as less noise being amplified throughout the system, the RADAR can detect and track targets at a greater distance and with higher fidelity than older legacy systems.
The ability to repurpose space on an aircraft already designed to house a MESA provides a significant budgetary advantage over the acquisition of an AESA RADAR and retrofit. Compared to an AESA, the DELTA and NEMESIS RADARs are one third to one half the price, require no structural modification to the aircraft, and use no more power or cooling than is already available on board. Line Replaceable Units (LRUs) can conform to the space available. Whereas older MESA RADARs had a relatively low Mean Time Between Failure (MTBF), the DELTA and NEMESIS RADARs have calculated MTBF’s often times 10X higher than their predecessors. Furthermore, the new solid-state amplifier relies on graceful degradation. This means the power amplification source has built-in redundancy so there is no single point of failure, only minute losses in overall power, which means the system can continue operating with these failures, unlike single-point failure tube-based amplifiers.
Overall, AESA will someday fully supplant MESA on all fighter aircraft; that fact is inevitable. Economies of scale will bring down the price of AESAs and will make the MESA no longer viable. However, that day is not today nor will it be 20 or even 30 years from now. As technology continues to advance and demand for a low cost, but high performance, airborne RADAR continues to grow, MESA systems will remain a viable option. MESA RADARs can and will continue to grow capabilities at the same rate as their AESA counterparts. Upgrade or even replacement advanced MESAs will keep these types of RADARs in the sky for decades to come.