SEKISUI CHEMICAL CO., LTD. announced that its High Performance Plastics Company has recently developed a transparent and flexible radio wave reflection film for 5G communications by combining the SEKISUI’s distinguished film and optical adhesive technologies with the metamaterial technology of Meta Materials Inc.

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

SEKISUI's newly developed transparent, flexible radio wave reflection film for 5G communications.

Background of the development

In 5G and 6G radio wave communications, higher frequency ranges than conventional LTE (4G) services are used: Sub-6 (3.6 GHz or higher) and millimeter (24 GHz or higher) 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 recently been developed as a possible measure for solving such a challenge, SEKISUI directed attention to a transparent and flexible radio wave reflection film that would have a metamaterial structure and would not spoil the landscape.

Film structure.

The company has realized a transparent and flexible high-frequency radio wave reflection film, which can be used for not only millimeter wave ranges but also a wide range from 2 GHz to 60 GHz while featuring a total luminous transmittance of 95%

The film was developed integrating SEKISUI's technologies with Meta’s world-leading nano-patterned transparent metamaterial technology NANOWEB and its manufacturing technology RML.

Outline of the developed product

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 special adhesive layer.

Representation of wave reflection.

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 where it is installed.

Effect demonstration experiment

Moreover, using the simulation technology of DOCOMO Innovations, Inc., SEKISUI verified the effects of the product in the planning stage and confirmed the effects indoors in the Solution Co-creation Lab of MIRAIT Corporation.

Indoor radio wave environment improvement experiment simulated by DOCOMO Innovations, Inc.

Indoor radio wave environment improvement demonstration experiment with assistance provided by MIRAIT Corporation (28 GHz).

The demonstration experiment confirmed that a reflection film placed 30 meters away from the base station properly controls the reflection of the radio waves, thus improving the communications infrastructure across a wide area.

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, rolling stock and roadway infrastructure while exploring other applications.