The UK and Japan will work together on a joint sensor research project, combining their sixth-generation fighter jet radar programs.  

The countries signed a Letter of Arrangement (LOA) on February 15, 2022, according to a UK Ministry of Defence press release.  

The statement says the aim of the project is the development of a “universal radio frequency sensor technology” known as ‘JAGUAR’.  

“Designing, building and evaluating the JAGUAR system will take around five years, involving input from Leonardo UK and Japanese industry. Two demonstrators will be built within the project, one in each country, with the work and learning shared to maximise national expertise,” the statement explains. 

JAGUAR is described as able to detect threats in the air, on land and on sea, and to locate targets while avoiding detection by adversary surveillance systems. 

Further details remain unknown; thus, it is unclear if the new radar will be based on active electronically scanned array (AESA) technology currently featured in fifth-generation fighter jets. 

Work on the project is slated to begin in April 2022 and create 75 new jobs across the UK. 

The UK and Japan are both working on their sixth-generation fighters: the Tempest (developed jointly with Italy and Sweden) and the F-X (developed by a conglomerate of companies led by Mitsubishi Heavy Industries). 

In December 2021, the two countries agreed to jointly develop an engine demonstrator for the jets.