5G wireless communication services leverage millimeter-wave (mmW) frequencies in the 24 GHz to 71 GHz range (frequency range 2, or FR2). Beyond 5G and 6G services could offer ultra-fast connectivity exceeding 100 Gbit/s in the next decade. Frequencies ranging from 150-GHz to 300-GHz are potential candidates for these future networks but radio-wave absorbers, needed for packaging and modularization, must still be developed.
The absorbers reduce unwanted reflections and emissions from chips and modules across broad bandwidths spanning tens of gigahertz. Modern mmW and terahertz (THz) absorbers must perform strongly at wide incident angles to support integration with advanced antenna technologies, including beamforming and steering.
Researchers from the Institute of Science Tokyo (formerly Tokyo Institute of Technology), Hiroshima University, Tokyo University of Science, the National Institute of Information and Communications Technology (NICT), and Maxell, Ltd. developed wide-incident-angle radio-wave absorbers for mmW and THz applications. They introduced radio-wave absorbers using loop-shaped frequency-selective surfaces (FSS) that enhance co-design with antenna beamforming and steering based on wide-incident-angle absorption properties.
The absorbers can be applied to lower frequency bands such as 4G LTE, 5G, Wi-Fi, and Bluetooth because of the loop-shaped FSS. Transmission loss is reduced to below 7dB at 2.4 GHz. The absorbers achieve 90% wideband absorption across the 26.5 GHz–40 GHz range (for 30-GHz absorbers) and 95.4 GHz–181 GHz/328 GHz–431 GHz (for 150-GHz absorbers) at incident angles up to 60 degrees.
Why it matters
For engineers, the development of wideband radio-wave absorbers represents a major leap forward in designing and deploying next-generation communication networks. As 5G evolves and future 6G networks push into even higher frequencies, managing signal integrity becomes increasingly challenging. These absorbers address that need by reducing unwanted signal reflections and emissions, which can interfere with performance. By supporting wide-angle absorption and enabling smooth integration with advanced antenna technologies like beamforming and steering, these absorbers are essential for achieving the ultra-fast, reliable connectivity that future networks demand. Their adaptability across a range of frequencies, from 4G and Wi-Fi to emerging THz bands, offers engineers a versatile solution for current and future wireless designs.
Article Source: Wide-incident-angle wideband radio-wave absor | EurekAlert!
