Signal-permeable windows for easy penetration by radio waves

High-performance materials, multi-layered window glass and Low-E glass are being used more widely to improve the insulation of homes and offices for energy efficiency. As a consequence, however, it is becoming more difficult for high-frequency radio waves used by mobile phones and other applications to reach indoor spaces.

In response, DOCOMO and YKK AP are developing windows that allow radio waves to pass through easily while still maintaining high-performance thermal insulation. The plan is eventually to install such windows in the ceilings and walls of existing as well as new homes and offices.

DOCOMO and YKK AP will now test a prototype window made with aerogel, a high-performance thermal-insulation gel-like material, to confirm its radio-wave penetration characteristics. Aerogel is known to have a dielectric constant close to that of air and allows radio waves to penetrate easily. The demonstration will enable DOCOMO to test materials, shapes and window structures that best allow radio waves to pass through.

Going forward, DOCOMO will continue to work toward 5G Evolution & 6G by researching and developing technologies including windows easily penetrated by high-frequency millimetre and terahertz radio waves for high-quality indoor connectivity.

The initiative will be introduced during "docomo Open House '23," which will be held online from Thursday, February 2 2023 through the rest of the month.