India and Japan are nearing the finalisation of an agreement for the co-development and co-production of the advanced UNICORN radar system, marking a major milestone in strengthening bilateral defence cooperation. The update was shared by Japan’s Ambassador to India, Ono Keiichi, during the International Conference on India-Japan Cooperation in the Indo-Pacific held in New Delhi.
The UNICORN (Unified Complex Radio Antenna) mast is among the most advanced naval sensor integration systems currently in service, combining multiple radar arrays and communication antennas into a single enclosed structure. This configuration significantly reduces a warship’s radar cross-section (RCS), enhancing stealth while improving sensor efficiency and electromagnetic spectrum management.
Ambassador Ono noted that India-Japan defence collaboration has already reached a mature stage in the maritime domain, with the next phase focused on expanding interoperability across land, air, sea, and emerging domains such as cyber and space. This integrated, multi-domain approach aims to enable seamless joint operations in increasingly complex Indo-Pacific environments.
The foundation for this partnership was laid in November 2024, when both countries signed a memorandum of understanding for the joint development of UNICORN masts. With this agreement, India became only the second Asian nation, after the Philippines, to secure such a strategic collaboration with Japan. The initiative is regarded as a flagship project under their broader defence technology cooperation framework.
The UNICORN mast integrates radar, communication, and electronic warfare systems into a single stealth-optimized unit, eliminating the need for multiple exposed antennas. This enhances survivability in contested environments, improves situational awareness, and minimizes electromagnetic interference—an essential factor in modern naval operations.
India-Japan defence ties have steadily evolved since the signing of the 2015 Agreement on the Transfer of Defence Equipment and Technology, which has facilitated joint development and technology-sharing initiatives in advanced defence systems.
The UNICORN program was also a key topic during discussions between India’s External Affairs Minister S. Jaishankar and Japan’s Foreign Minister Toshimitsu Motegi during the latter’s visit to New Delhi in January. These engagements have helped accelerate progress and align strategic priorities, bringing the agreement closer to completion.
