On August 21, the Japan Ministry of Defense (JMOD) and Ministry of Foreign Affairs (MOFA) indicated that further progress had been made to transfer to India a number of Japan’s indigenously-developed ‘Unified Complex Radio Antenna’ (UNICORN). The move would mark Japan’s first transfer under a bilateral defense equipment and technology agreement signed by the two countries in 2015.
At last week’s Japan-India Foreign and Defense Ministerial Meeting (“2+2”) in New Delhi, the third held within the last five years, Japan’s Minister of Foreign Affairs KAMIKAWA Yoko and Minister of Defense KIHARA Minoru and their Indian counterparts S. Jaishankar and Rajnath Singh also announced that the two countries had successful completed joint cooperation on Unmanned Ground Vehicles (UGVs) and Robotics.
The UNICORN, also known as the ‘NORA-50’ and co-developed by Japan’s NEC Corporation, Sampa Kogyo K.K. and Yokohama Rubber Co., Ltd., is a state-of-the-art integrated antenna system currently in use by the Japan Maritime Self-Defense Force (JMSDF) for its fleet of Mogami-class ‘30FFM’ multi-mission stealth frigates. Japan’s Acquisition, Technology & Logistics Agency (ATLA) explains that the UNICORN mast constitutes advanced stealth technology as it features an integrated antenna array covered with a low radar cross section (RCS) radome (radar and dome).
This NORA-50 stealth antenna system combines innovative technology accumulated by the three Japanese companies. NEC leverages its expertise in Tactical Air Navigation Systems (TACAN) and hardware systems integration, Sampa Kogyo its naval antennae design and maintenance, and Yokohama Rubber its radome manufacturing technology for lightning resistance and high radio wave transmittance.
UNICORN was developed with the aim of combining the array of individual antennae that are conventionally situated in exposed locations on the mast-tops of naval vessels into a single mast while also balancing the need to achieve an optimal configuration for the integrated antennae to preclude mutual interference. The mast also needed to have reduced RCS, lightning resistance, as well as easy installation and repairability.
A unique TACAN unit, which adopts a hollow donut rather than conventional disc shape, is placed at the bottom rather than top of the vessel’s mast in order to reduce detectability but it is able to nevertheless maintain smooth multi-directional transmissions. Each of the integrated antennae has a low RCS and improved stealth performance while the entire UNICORN unit is covered with a radome to provide weather resistance.
Preliminary studies for the UNICORN antenna systems were first conducted by NEC Corporation, Sampa Kogyo K.K. and Yokohama Rubber Co., Ltd in 2015 and 2016. The three companies subsequently signed a mass production contract with ATLA in 2018, whereupon the first UNICORN unit was delivered to the JMSDF in 2020. Two units per year have since been produced per year for use on Mogami-class frigates and the UNICORN is expected to continue production well into the future.
Japan and India have sought to strengthen their security and defense ties in recent years. Both nations are participating in Quad security meetings with Australia and the United States to strengthen the rules-based international order, and Tokyo sees New Delhi as an important partner with which to strengthen naval cooperation.
