Late 60s & early 70s US Phased Array Airborne Radar designs

[JFC Fuller]

I was trying to work out what sort of radar the USN had in mind for the F-14C (Link), Congress was told that:

The multi mode radar will feature an [deleted] electronically scanned array radar with [deleted] nautical mile detection range and organized through a central multi processor. The track-while-scan mode is significantly improved by increased data rates, dual confirm detection logic and adaptive tracking. All target aspect detection [deleted].
Improved lighter defensive ECM sensors will also be provided including [deleted]. Improved air-to-ground accuracy including all weather delivery will be a fall out of the multi-mode radar technology.

I then started looking for evidence of contracted development work for multi-mode electronically scanned array radars undertaken for the USN in the 1968-71 timeframe. I came across the Hughes Electronically Scanned Airborne Intercept Radar Antenna (ESAIRA). The following text appears to be a generic blurb that was used in various forms by multiple publications:

A new electronically scanned airborne radar antenna, the US Navy's first-high performance, X-band multimode, phased array system is now undergoing evaluation at Hughes. It has a 36-inch-diameter flat reflecting surface with 2400 radiating elements, and offers distinct advantages over mechanically-scanned gimballed antennas. It is designed for air-to-air search, multiple target tracking, terrain following and avoidance, and ground mapping

The navy also funded, though at just $70,000 for each team, the Molecular Airborne Intercept Radar (MAIR). The two teams consisted of Westinghouse and Texas instruments in one and Raytheon and Microwave Associates in the other. Good contemporary article available here (Link).

I am not saying this, or the MAIR work, would have been the radar for the F-14C, rather that this was te foundational R&D that would have eventually informed a set for the F-14C.

 

[overscan (PaulMM)]

Renamed and broadened topic for unbuilt US phased array righter radar proposals of the 1960s and early 1970s.
late

Westinghouse experimental airborne phased-array radar, shown installed aboard a McDonnell Douglas F-4J, is one candidate for use on USAF's proposed F-15 air superiority fighter. Photo by Charles F. Hickey, Westinghouse Aerospace Div.

AWST 10 Nov 1969

 

[overscan (PaulMM)]

A very interesting article on phased-array radars from Electronics 2nd September 1968

 

[overscan (PaulMM)]

As far as I can see, every radar manufacturer and their dog made phased array airborne radar designs, with a great spread of different technologies.

 

[F-2]

As far as I can see, every radar manufacturer and their dog made phased array airborne radar designs, with a great spread of different technologies.

It’s basically a mechanical scan radar with a unique antenna design, even going back to WWII different electronic beam scanning was experimented with. I guess it’s just a natural evolution.

 

[F-2]

The APQ-164 (shown in figure 15) was built upon the foundation
of existing hardware. The APG-68 provided the transmitter, LPRF,
and PSP designs while the two-axis electronically scanned antenna
was a direct result of the Electronically Agile Radar (EAR) radar
developed and flight tested by Westinghouse for the Air Force
Avionics Lab. The two principal modes, TF/TA and SAR, were
demonstrated as part of the EAR flight test on the B-52 A/C.
The modes of operation for the APQ-164 are shown in figure 16.
The two principal modes of operation are TF/TA and SAR. In
addition the APQ-164 radar provides noncoherent mapping
modes, ground moving target indication and ground moving target
track, precision position update, precision velocity update, and
beacon weather modes.

The key feature of the APQ-164 radar is its use of a two-axis
electronically phased array antenna. The chief benefits are shown
in figure 17. Better performance arises because of the rapid beam
switching times permitting interleaving of the various air-to-ground
modes with TF/TA. The MTBF of the antenna is estimated to be
in excess of 10,000 hrs, a number demonstrated on the EAR and
High Energy Laser Radar Acquisition and Tracking (HELRATS)
programs. More importantly the design permits graceful degrada-
tion in performance in the event of an antenna module failure.
The modes of operation for the APQ-164 are shown in figure 16.
The two principal modes of operation are TF/TA and SAR. In
addition the APQ-164 radar provides noncoherent mapping
modes, ground moving target indication and ground moving target
track, precision position update, precision velocity update, and
beacon weather modes.