Britain and Japan agreed to jointly develop a new design for Jaguar, a multi-function radar sensor antenna. This project comes after British jet engine manufacturer Rolls-Royce and Japanese counterpart IHI began developing a new jet engine for the British Tempest and Japanese FX stealth fighters. The radar sensor can be used in any jet fighter and the two partners believe they can complete the work within five years. The new engine is more complex and will take ten years to reach the prototype stage.
Jaguar can be used to update existing Japanese and British fighters, including the F-35s both nations have bought. The sensor will be manufactured in Japan and Britain and both will seek export customers. Jaguar will not use any American tech or components and be exportable to nations without American permission.
Jaguar is a passive sensor as it does not emit any signals revealing its presence and is designed to better detect stationary and moving targets, including stealth aircraft. Jaguar will use software developed primarily by the Japanese, who have a reputation for developing effective and reliable software for consumer and industrial products. Because of that Japanese software firms are already developing systems comparable, and in some cases, superior to those used in the F-35. There may be future collaboration with Britain on this since such software will be essential to making Tempest competitive. Tempest already has some European partners and having Japan involved in developing some of the needed components is seen as beneficial for the FX project as well.
Japan changed its post-World War II constitution in 2014 to allow weapons exports for nations that are not at war or under weapons sanctions. This move was caused, in part, by the high cost of developing modern military systems that are only for Japanese forces. Over the last two decades South Korea has been successfully exporting similar systems, which means South Korean systems were much less expensive than comparable Japanese ones. Without exports some Japanese manufacturers were refusing to build systems just for the Japanese forces because that manufacturing capacity was needed for more profitable export items. There was also an element of national pride in this as Japanese long regarded Koreans as less capable neighbors who had now caught up with Japan economically and militarily.