1940s

Raytheon’s connection with tactical fighter radars began during World War II when renowned aviator Howard Hughes’ new aerospace company gained a reputation for innovation in the defense industry. Concurrently, Raytheon Company was developing radar technology for anti-aircraft air defenses and gun control systems for bomber aircraft. After the war, Hughes Aircraft Company, which would later merge with Raytheon, won a contract to develop the E-1 Fire Control System for fighter aircraft—including the F-89 Scorpion and the F-94C Starfire—of the new U.S. Air Force. The system used the APG-33 radar to continuously measure the range, azimuth and elevation of the identified target and allow the observer to take control if the “blip” was identified as unfriendly. By the end of the decade, Hughes had completed production on 25 such systems. Along with its work on the E-Series systems, Hughes began development on the MA-1, a fire control system that incorporated the new Falcon missiles.

A Convair F-106 Delta Dart with the Hughes MA-1 Weapon Control Radar incorporating the first airborne digital computer.

Lockheed F-94C Starfire cockpit with E-5 radar installed.

Hughes MA-1 Weapon Control Radar.

An APG-40 radar antenna is inspected during routine maintenance on board a Lockheed F-94C Starfire Interceptor. Part of the Hughes E-5 fire control system, the increased dish diameter and transmitter power produced more than twice the range of earlier radars.

An APG-40 radar antenna is inspected during routine maintenance on board a Lockheed F-94C Starfire Interceptor. Part of the Hughes E-5 fire control system, the increased dish diameter and transmitter power produced more than twice the range of earlier radars.

1950s

New conflicts in Korea and elsewhere during the 1950s demanded rapid developments in fire control radars, including increasingly automated functions such as search and “collision-course” automatic interception. Hughes’ engineers worked to improve the systems’ seek-out and shoot-down capabilities, adding such innovations as an artificial horizon and range trace marker to later E-Series systems. These markers displayed on the scope until the radar could lock on to the target. By the mid-1950s, Hughes was the sole source of fire control systems for the U.S. Air Force Interceptor program and radar-guided Falcon series air-to-air missiles. After WWII, Raytheon had begun development on the APG-43, a continuous wave radar used in anti-aircraft missiles that was immune to interference from large stationary objects and slow moving clutter. This radar was at the core of Raytheon’s Lark Missile guidance system—the first missile-mounted system capable of intercepting moving objects.

North American F-86D Sabre Interceptor with Hughes E-4 Fire Control System. 

The APG-33 radar for the E-5 Fire Control System.

A Northrop F-89D Scorpion displaying the Hughes E-6 Fire Control System.

The Hughes E-6 Fire Control System with APG-40 radar.

The Hughes E-6 Fire Control System with APG-40 radar.

1960s

After the Korean War, the Vietnam War raged against a backdrop of ongoing Cold War posturing. Hughes continued to manufacture high performance E-Series fire control radar systems for tactical fighters in both America and Canada, including those that flew on the U.S. Navy and Marine Corps F2H-4 Banshee and the F3D Skyknight. The ASG-18 was the first Pulse Doppler radar in the U.S. This new system had look-down/shoot-down capability, an infrared search-and-track system, and a range of more than 200 miles. This system was first designed for the F-111 Aardvark and tested on the “Snoopy” B-58 bomber, so called because of the shape of its reconfigured nose to fit the radar. However, after cancellation of the F-111 program, the ASG-18 was installed on the YF-12A Blackbird Interceptor.

ASG-18 Pulse Doppler Radar.

The U.S. Navy's F2H-4 Banshee equipped with the Hughes E-10 high-power Fire Control System.

AIM-47 missile waiting to be loaded into the Lockheed YF-12A Blackbird.

Lockheed YF-12A Blackbird Interceptor with Hughes ASG-18 Pulse Doppler Radar.

Lockheed YF-12A Blackbird Interceptor with Hughes ASG-18 Pulse Doppler Radar.

1970s

The 1970s ushered in a new era of radar technology, as tactical fighters came to rely on newly developed mechanically scanned array radars. Hughes developed the all-weather, multimode APG-63 radar in the early 1970s, which was installed on all F-15s. This radar was upgraded to the APG-70 in 1979 to incorporate the first software programmable signal processor. This upgrade allowed engineers to modify the system by reprogramming the software rather than retrofitting the hardware—a development so significant that it distinguishes the F-15A/Bs from the C/Ds that remain in service in the U.S. Air Force and the air forces of several other countries. Other radar advancements during the 70s included velocity search, range-while-search capabilities, track-while-scan, and single target track operating modes.

An F-15 Eagle with open radome revealing the APG-63 radar.

All F-15s were equipped with Hughes APG-63 or APG-70 radars.

An APG-63 undergoing radar cross section performance measurements in an anechoic test chamber.

The APG-70 mechanically scanned array radar featured the first software programmable signal processor in the late 1970s.

The APG-70 mechanically scanned array radar featured the first software programmable signal processor in the late 1970s.

1980s

With the latest advancements still making waves, Hughes and Raytheon launched a new round of radar designs in the 1980s that incorporated gate array technology with additional modes, enhanced operational capabilities and greater reliability. Similar to the APG-63, the APG-65 was developed for the U.S. Navy’s F/A-18 Hornet, the McDonnell Douglas AV-8B Harrier II and the Douglas F-4 Phantom. The AWG-9 and APG-71 fire control systems offered a complete all-weather, multimode digital radar system for the Grumman F-14 Tomcat. This new system improved not only the digital processing speed of previous radars but also the mode flexibility and detection range, and it proved less vulnerable to jamming. In the late 80s, Hughes engineers upgraded existing radars to incorporate the JOVIAL programming language, allowing them to adapt software written for earlier radars. They also improved the motion-sensing subsystem and stretch waveform generator resulting in higher-resolution ground maps.

Gate array waveguide (foreground) and slotted plate antenna (background).

The Grumman F-14 Tomcat featured the AWG-9 Fire Control System and later the APG-71 radar system.

The APG-65 mechanically scanned array radar for the McDonnell Douglas F/A-18 Hornet.

The APG-65 radar adapted to fit the U.S. Marine Corps AV-8B Harrier II.

The APG-65 radar adapted to fit the U.S. Marine Corps AV-8B Harrier II.

1990s

By the 1990s, with Hughes/Raytheon serving as industry leaders in tactical fighter radars, the APG-63 series was still in use on the F-15C/D and the Slam Eagle aircraft. New hardware designs for that radar increased its reliability tenfold, allowing Raytheon’s improved radar to track 14 targets simultaneously. The APQ-180—a modified APG-70—saw improvements to its gimbaling scheme for the planar array and incorporated new air-to-ground modes. The new and improved radar was soon installed on the AC-130 gunship. Along with significant radar enhancements and enabling technologies, the 1990s saw the alignment of Raytheon and Hughes capabilities when Raytheon acquired Hughes in 1997.

An APG-73 fire control radar is installed into anF/A-18 Hornet. The radome swings open and the radar glides forward on rails to allow access to the entire system.

An APG-73 fire control radar is installed into anF/A-18 Hornet. The radome swings open and the radar glides forward on rails to allow access to the entire system.

A technician inspects the APG-70 radar installed into one of the first F-15E Strike Eagles.

The AC-130 gunship uses the APQ-180 radar system adapted from the APG-70.

2000s

The new millennium brought with it incredible advancements in tactical fighter radars—active electronically scanned arrays—quickly replacing the older mechanical scanning technology. The enabling technology for these new AESAs was the Gallium Arsenide Microwave Monolithic Integrated Circuit (GaAs MMIC) on a single chip. Raytheon first implemented the new AESA technology through upgrades to existing APG-63 radars, which allowed pilots in the retrofitted F-15C Eagle and other fighters to take advantage of the latest tracking capabilities and situational awareness. The first operational tactical AESA radar—the APG-63(V)2—was flown in an F-15C December 2000 out of Elmendorf Air Force Base, Alaska.Raytheon provided further enhancements for the U.S. Navy’s F/A-18E/F Super Hornet and EA-18G Growler aircraft with its APG-79 AESA radar. This radar’s active electronic beam scanning allows pilots to steer the radar beam at nearly the speed of light, optimizing situational awareness and providing superior air-to-air and air-to-surface capability. Other features of Raytheon’s line of AESA radars include cooling systems and radio frequency tunable filters that enable the radar and the electronic warfare hardware to operate simultaneously without degrading each other. In 2007, Raytheon was selected by the U.S. Air Force for the F-15E Strike Eagle Radar Modernization Program which became the APG-82(V)1 radar. Aircraft equipped with this AESA can simultaneously detect, identify and track multiple air and surface targets at longer ranges than ever before. The longer standoff range facilitates persistent target observation and information sharing for superior battlespace awareness.

The first operational tactical AESA radar, the APG-63(V)2 on an F-15C.

APG-79 AESA line replaceable units (LRUs) can be exchanged in thefield adding new modes quickly.

The F/A-18 Super Hornet ushers in a new era for the multirole strike fighter.

The APG-63(V)3 AESA radar for the Boeing F-15C Eagle and F-15E Strike Eagle aircraft.

The APG-79 AESA radar for the Boeing F/A-18E/F Super Hornet and EA-18G Growler.

2010s

Raytheon's technology experts know that today's multirole aircraft require multirole technology to maintain combat superiority. With extended detection ranges and simultaneous air-to-air and air-to-ground capabilities, Raytheon’s line of advanced combat radars was specifically designed for the global fighter upgrade market. These radars—including the APG-79(V)X and the APG-84—are designed to slip easily into an aircraft’s nose cone. The simple retrofit can be performed in the field and takes less than an hour to complete. The significantly upgraded radar capability helps countries extend the tactical relevance of their existing F-16, F-18 and other aircraft in a time of tighter budgets, ensuring combat effectiveness for years to come. Raytheon delivered its 500th AESA radar system in 2013 and the 500th APG-79 AESA November 2014.

The Raytheon family of advanced combat AESA radars.

Black and white images are from the Hughes Aircraft Company historical photo archives. Boeing F/A-18 Super Hornet photo in decade 2000 courtesy of Boeing Company. Use of U.S. Department of Defense (DoD) visual information does not imply or constitute DoD endorsement. All other images Raytheon Company.