In this fortnightly online column, ADM journalist Corey Lee Bell covers defence news across Japan and the Republic of Korea.
Hitachi Kokusai Electric has won a contract from Japan’s Ministry of Defense (MoD) to develop high-power microwave (HPM) technology.
According to a document recently released by the Acquisition, Technology & Logistics Agency (ATLA), the company was awarded a tender worth ¥1.3 billion (approx. A $12 million) on 31 March for a study on “enhanced efficiency and performance” HPM equipment.
The optional (i.e. non-competitive) contract followed on from Hitachi’s successful bid for a ¥30 million (approx. A $270,000) scoping study on the same theme in March 2025.
Little information on the project has been made public. However, a summary of ongoing research on “high efficiency and high performance HPM equipment” is contained in a November 2025 brochure from ATLA’s Defense Innovation Science & Technology Institute (DISTI).
Key features listed for this technology are the use of a distributed array antenna, the capability to immobilise airborne objects at 10 times the range of current systems, and a facility for delivering wireless charging to high-altitude platform stations (HAPS).
MoD plans for developing HPM technology were first presented in a policy evaluation report in 2013, which proposed research on a new missile defence HMP system featuring active phased array technology.
Following a series of promising preliminary tests, the development of HPM was listed as a priority in the MoD’s 2019 “Research and Development Vision” document.
Citing this document, new roles and a heightened emphasis for HPM equipment were introduced in a 2022 policy evaluation report compiled by ATLA’s Department of Technology Strategy.
This highlighted the advantages of HPM systems’ capacity to immobilise multiple targets simultaneously, presenting a more effective and economical alternative to kinetic weapons for countering modern tactics such as saturation attacks employing low-cost drones.
It also noted the importance of Japan both capitalising on its research breakthroughs to become a HPM defence technology leader, and accelerating further progress through international cooperation.
Recognition of Japan’s achievements in this field led to the United States Department of Defense (now Department of War) and Japan’s MoD signing the Project Arrangement concerning Cooperative Research on High-Power Microwave (HPM) Systems in July 2024, which paved the way for joint tests and the sharing of test data.
In recent years ATLA has continued to offer research and testing tenders focusing mainly on anti-drone HPM systems, with one document from the Ground Self-Defense Force’s (JSDF) Air Defense School published in April identifying targets for preliminary tests as nano (13-14cm long) to medium sized (90-95cm long) drones.
A main winner has been wireless electronics provider Japan Radio, which since 2023 has won a series of study and demonstration contracts totalling ¥9.7 billion won (approx. A $87 million).
Japanese research on microwave power transmission technologies began in the mid-1990s, but has until recently been primarily orientated towards civil uses including non-military satellites, with key contributors including the Japan Aerospace Exploration Agency (JAXA), Panasonic Holdings, Mitsubishi Research Institute and public universities.
Military uses of this application have accelerated in recent months, with an April report indicating that Chinese scientists have successfully trialled wireless charging for an airborne drone via a ground-based microwave emitter.