The U.S. Air Force and the F-35 Joint Program Office (JPO) are mum on the service’s fiscal 2024 budget request for and the testing of the Northrop Grumman [NOC] AN/APG-85 Active Electronically Scanned Array radar, which is to replace the company’s AN/APG-81 radar for the Lockheed Martin [LMT] fighter.
Last week, Air Force Lt. Gen. Richard Moore, the service’s deputy chief of staff for plans and programs, said that “we are getting very close to the new radar on the F-35” and that the APG-85 would be “a dramatic increase in our ability to operate with electronic warfare and electromagnetic spectrum operations kinds of things.” but he demurred when asked about the amount that the Air Force requested in fiscal 2024 for the APG-85 (Defense Daily, July 20).
The Air Force then referred that question to the F-35 JPO.
“Funding information associated with this [APG-85] effort is not available for release at this time,” the F-35 program wrote in a July 25 email. “Test program details are not available for release at this time.”
A Mitchell Institute for Aerospace Studies’ report last month said that the APG-85, which is to field in F-35 Lot 17 under the Block 4 upgrade, will have twice the capability of the APG-81 and “is a powerful cornerstone of the F-35’s sensor suite.”
“The difference from an operational perspective is comparable to switching from 1990s-era dial-up to 5G internet,” the report said.
The APG-85 “can suppress, defeat, and deny the enemy’s use of the broad electromagnetic spectrum,” the study said. “This also enables better targeting of surface or airborne radars at further ranges. Additionally, standoff threat suppression operations will be significantly more effective in the support of a strike package and improve the survivability of terminally guided weapons being employed against high-value surface-to-air missile sites.”
In addition, “with fidelity improvements realized from the AN/APG-85 in reducing target location errors, and a significant [sic] increased jamming capability against targeted threat radars, the aircraft will gain improved weapon delivery accuracy and can attain an increased probability of kill,” Mitchell said. “That means a more efficient use of weapons per aircraft and the ability to service more single weapon targets per sortie. This is a big deal when commanders will need to expand the number of aim points that can be hit in a concentrated period of time.”
In January, Northrop Grumman disclosed the development of the APG-85, but the company and the F-35 program did not reveal funding levels nor contract details for the radar (Defense Daily, Jan. 11). Northrop Grumman builds the APG-81 at the company’s Linthicum Heights, Md., plant.
The F-35 JPO has said that the APG-81 has 1,676 Gallium Nitride (GaN) transmit/receive modules, but the F-35 JPO and Northrop Grumman declined to say whether the APG-85 will also be a Gallium Nitride-based radar.
Early this year, retired Air Force Lt. Col. Mike “Pako” Benitez, the former director of staff for the Air Force 53rd Wing, the service’s primary operational test wing, suggested in his newsletter, The Merge, that the APG-85 is likely a GaN radar.
“GaN chips have three times the bandgap width as a silicon chip, meaning they can move more electrons with less energy loss (i.e. heat), and they can sustain higher temperatures than silicon,” he wrote.
The benefits of GaN radars include “increased detection range (read: small and stealth targets); smaller package (read: mobile and multi-domain use cases); [and] wider range of operating frequencies (non-traditional spectrum operations, harder to jam, etc.),” Benitez wrote.
Northrop Grumman, Lockheed Martin, and RTX [RTX] have invested funds in GaN radars.