A collaborative research team, including Institute of Science Tokyo (formerly Tokyo Institute of Technology), has developed wide-incident-angle radio-wave absorbers for millimeter-wave and terahertz applications. These absorbers demonstrate wideband frequency absorption up to an incident angle of 60 degrees, made possible through the use of frequency selective surface (FSS) patterns. This innovation greatly improves the absorbers' efficiency in advanced communication systems, such as 5G and Beyond 5G networks. Notably, the absorbers also allow low-frequency signals, like Wi-Fi, to pass through, distinguishing them from conventional absorbers. This dual functionality makes them highly versatile and suitable for modern communication systems that demand both high-frequency signal absorption and low-frequency transmission.