SEKISUI CHEMICAL Develops Transparent and Flexible Radio Wave Reflection Film for 5G Communications

SEKISUI CHEMICAL CO., LTD. is pleased to announce that its High Performance Plastics Company has developed a transparent and flexible type of radio wave reflection film for 5G communications by combining SEKISUI's distinguished film and optical adhesive technologies with the metamaterial technology of Meta Materials Inc. headquartered in Canada.

SEKISUI verified the radio wave environment of the film with collaboration from DOCOMO Innovations, Inc. headquartered in the U.S. and confirmed that the product, having unprecedentedly high transparency and radio wave diffusion characteristics, provides wide frequency coverage useful for 5G and 6G communications.

Background of the development
In 5G and 6G radio wave communications, higher frequency ranges than conventional LTE (4G) services are used: Sub-6 and millimeter wave ranges. Millimeter waves feature a high transmission capacity but have strong directivity; when reaching a shielding object such as a building, they attenuate, deteriorating communications quality. Installing a base station or relay station may resolve the deterioration, but such a solution involves a high additional investment, and a more reasonable cost solution was demanded.

While millimeter wave reflection plates, which have a metamaterial copper pattern processed on the printed circuit board, have been developed as a possible measure for solving such a challenge, SEKISUI directed attention to transparent and flexible radio wave reflection film that would have a metamaterial structure and would not spoil the landscape. Believing that it would be able to provide a solution by incorporating its film and optical adhesive material technologies into such a transparent, flexible plate, SEKISUI has been committed to research and development efforts.

The company has realized a transparent and flexible type of high-frequency radio wave reflection film, which can be used for not only millimeter wave ranges but also a wide band ranging from 2 GHz to 60 GHz while featuring a total luminous transmittance of 95% by integrating SEKISUI's technologies with Meta's world-leading nano-patterned transparent metamaterial technology NANOWEB (R) (*1) and its manufacturing technology RML (R) (*2).

Product outline
This film consists of a metamaterial layer that has a high-frequency radio wave reflection structure, highly transparent adhesive, special coating that protects the film surface, and a special adhesive layer. When placed on a surface such as a wall or ceiling, the film reflects radio waves, enabling them to reach shielded areas. This technology can improve a communications environment at a lower cost and in a shorter period of time, compared with the installation of a base station or relay station. The film, which is transparent and flexible and does not require a power connection, can be installed anywhere, on a surface of whatever shape, without spoiling the appearance of a place where it is installed.

Effect demonstration experiment
Using the simulation technology of DOCOMO Innovations, Inc., SEKISUI verified the effects of the product at the planning stage and confirmed the effects indoors in the Solution Co-creation Lab of MIRAIT Corporation headquartered in Tokyo. The demonstration experiment confirmed that a sheet of reflection film placed 30 meters away from the base station properly controls the reflection of radio waves, thus improving the communications infrastructure across a wide area.

Future plans
Using the advantages of transparency, flexibility, light weight and operation without power connection, SEKISUI plans to distribute the product for use in office buildings, factories, shopping malls, medical and care facilities, various sports facilities, farms, ranches, smart cities, underground shopping streets, rolling stock and roadway infrastructure while exploring other applications, including temporary or emergency sites providing first-aid services, construction sites, and camping areas. SEKISUI plans to start distributing sample products in fiscal 2022, aiming to achieve a sales target of 6 billion yen by fiscal 2026.