Toray Creates Thinnest mmWave Absorption Film for 5G Device

Toray Industries, Inc. has developed a film that can efficiently absorb millimeter wave (note 1) band electromagnetic waves employed in 5G communications and other applications. The film delivers an absorption capacity of at least 20 decibels (99%) for millimeter waves and makes it possible to select absorption frequency. Also, it is one-fifth the thickness and one-tenth the weight of conventional counterparts (note 2). Specifically, the film eliminates electromagnetic interference in 5G devices incorporating millimeter wave modules. It also helps lighten devices and enhance design flexibility.

Recent years have witnessed intensive technological development to materialize a smart economy. Efforts have included rollouts of smart factories using millimeter wave-based local 5G networks and millimeter wave radar communications for automated driving. Specifically, millimeter wave technology offers several benefits. Among them are a 100-fold boost in speed and capacity over conventional setups, a latency one-twentieth of 4G setups, and multi-point simultaneous connections. However, there are also downsides. Notably, electromagnetic interference from reflections and interference from the strong linearity of millimeter waves are a problem.

Electromagnetic sheets absorbing millimeter waves can resolve those issues. The problem with regular sheets is that they are heavy from extensively using metal particles to absorb these waves. Specifically, they should be several millimeters thick to ensure absorption. Deploying such sheets with 5G devices has been challenging because of design flexibility and handling ease tradeoffs.

PICASUS nano-multilayer film by Toray

Accordingly, Toray resolved these issues by applying its proprietary nano-multi-layer film technology. It created a millimeter-wave absorption film with alternating low- and high-dielectric layers. That multilayer structure streamlines millimeter-wave absorption. The sheet is far thinner than conventional counterparts despite its absorption capacity of at least 20 decibels, making it far lighter. Changing the film’s thickness has made it possible to absorb frequencies between 20 and 100GHz.

Mainly, applying this film around millimeter wave modules can eliminate electromagnetic interference without undermining product design flexibility. Toray’s film is easy to install in smart factories and other sites and resolve malfunctions between devices.

Toray will keep researching and developing innovative materials and technologies to help create a smart economy in line with its corporate philosophy of contributing to society by creating new value through innovative ideas, technologies, and products.


1. An electromagnetic wave with a wavelength of 1 to 10 millimeters, for a frequency of 30 to 300 gigahertz.

2. Based on comparisons between commercially available products absorbing 77 gigahertz and weights of 10-square-centimeter samples.