Stealth Antenna Deal Marks a New Watershed for India-Japan Defense Cooperation

In an epoch-making development, Japan and India have signed a Memorandum of Implementation (MOI) for Tokyo’s planned export to New Delhi of an advanced integrated stealth antenna system that is currently used for the Mogami-class multirole frigate of the Japan Maritime Self-Defense Force (JMSDF).

Once implemented, this would be Japan’s first export of defense equipment to India under the bilateral agreement on defense equipment and technology transfer signed in December 2015.　

This would also be Japan’s second export of finished defense equipment to a foreign country, following the transfer of air surveillance radar systems to the Philippines.

At a ceremony at the Embassy of India in Tokyo on November 15, Sibi George, the ambassador of India to Japan, and Ishikawa Takeshi, commissioner of the Acquisition Technology and Logistics Agency (ATLA) under the Japanese Ministry of Defense signed the MOI.

“The signing of this MOI is a very significant milestone for both Japan and India towards the realization of the transfer of the UNICORN,” Japan's new Defense Minister Nakatani Gen said at a press conference on November 15.

“Japan and India have a special strategic and global partnership. It is extremely important for the peace and stability of Japan and the region that defense cooperation with India develops into defense equipment and technology cooperation as part of regional defense cooperation,” Nakatani stressed.

The move came after foreign and defense ministers from the two nations agreed on a series of measures to enhance their bilateral cooperation in defense equipment and joint exercises at the third 2+2 ministerial meeting in New Delhi on August 20.

What is interesting is that, while Japan has so far explained that it will transfer, or export, the finished UNICORN to India, India said the agreement is for co-development of the UNICORN mast to be equipped onboard ships of Indian Navy.

“The Indian Navy is pursuing the induction of these advanced systems which will be co-developed by Bharat Electronics Limited in India with Japanese collaboration,” India’s Ministry of Defense said in a statement.

“When implemented, this would be the first case of co-development / co-production of Defence Equipment between India and Japan,” the statement added.

The advanced naval ship communication antenna system, which is set to be transferred to India, is called “UNICORN.” The name stands for “Unified Complex Radio Antenna.”

UNICORN was jointly developed by three Japanese companies, namely NEC Corporation, Sampa Kogyo K.K., and the Yokohama Rubber Co., Ltd., with NEC as the main contractor.

Yokohama Rubber said it was in charge of developing the antenna cover, or radome, that covers the entire UNICORN. Utilizing the technology it has cultivated in developing radomes for aircraft, it maximizes radio wave transparency while also providing basic weather resistance and lightning resistance to protect the antenna from lightning strikes.

By stacking multiple antennas one on top of the other and covering the entire system with the radome, UNICORN can reduce the radar cross section (RCS) of the antennas, which increases stealth by making it more difficult for any enemy to detect naval vessels.

In contrast, conventional ships have had multiple antennas mounted individually on their masts.

UNICORN (in its NORA-50 variant) is currently fitted on Mogami-class frigates exclusively.

The JMSDF plans to build a total of 12 Mogami-class frigates, with plans to acquire a new class of 12 FFMs from fiscal year 2024 until 2028. The new frigates will essentially be improved large Mogami-class ships that are set to be built to the design proposed by Mitsubishi Heavy Industries.

As part of the Royal Australian Navy’s Tier 2 / SEA3000 requirement, Australia has listed the Mogami-class frigate of the JMSDF and Germany's MEKO A-200 as the final two candidates for the navy’s next frigate ahead of a final selection next year.