India and Japan signed an agreement for the co-development of a naval radio antenna based on Japan’s UNICORN system. The announcement occurred during the visit of Prime Minister of Japan Sanae Takaichi to India.
Prime Minister of India Narendra Modi revealed the development during a joint press briefing, stating:
In the field of defence, today we have signed an agreement for the first-ever co-development project between India and Japan. This Naval Radio Antenna project will open a new chapter in our defence technology partnership. Going forward, we will jointly develop defence technologies that will strengthen regional peace, maritime security, and a rules-based order.
This is among the most tangible outcomes of India – Japan defence cooperation, which has been limited to joint exercises and other activities so far. Earlier, Indian procurement of the Shinmaywa US-2 seaplane was discussed for years before being shelved. DRDO and ATLA had also jointly researched Visual SLAM based GNSS Augmentation Technology for UGVs.
As early as 2022 India and Japan were in discussions regarding the UNICORN. In 2024, the foreign and defence Ministers of both nations “appreciated the progress made for the transfer of Unified Complex Radio Antenna (UNICORN) and related technologies and early signing of related arrangements.”
UNICORN is currently used on the Mogami-class frigates of the JMSDF. The Indian Navy is likely to equip its next generation warships with the UNICORN derivative. In 2025, Indian shipyard MDL had also indicated preliminary discussions regarding a common destroyer designed between India and Japan.
UNICORN integrates various antennas into a single mast to improve stealth. From top to bottom this includes an ES-R antenna, ES-C antenna, WiFi band antenna, LINK-16 antenna, UHF antenna, IFF antenna, U/VHF antenna and TACAN antenna. UNICORN was jointly developed by three Japanese companies: NEC, Sampa Kogyo and Yokohama Rubber. The prime contractor NEC provided hardware integration and Tactical Air Navigation (TACAN) systems. Sampa Kogyo provided antenna technologies and maintenance experience while Yokohama Rubber developed the frequency selective radome. Saab had recently pitched its SLIM integrated mast solution.
During DefExpo 2022, Indian Navy’s Directorate of Electrical Engineering had showcased a project for two phase development of an Indigenous Integrated Mast (IIM) with Bharat Electronics Limited (BEL) as the production partner. The current status of the project remains unclear. It is likely that the project will be progressed or merged with the localized adaptation of UNICORN.
IIM Phase-I was required to have a height of 11m without a radome, involving the “integration of R-ESM, COMINT, V/UHF communication and Data Link Antenna on a single mast without Radome. The final design envisages installation of data Link (L Band) antenna on top most part of the IIM, thereafter COMINT and ELINT antenna would be installed. The bottom most antenna will comprise Rhode and Schwarz make antenna for V/UHF communication.” IIM Phase-II envisaged the development of a shorter mast with a height between 8 – 11m with a frequency selective radome, integrating R-ESM, COMINT, L Band Data Link, two sets of V/UHF communication antenna and an optional WiFi antenna.
