A transparent and flexible microwave absorber covering the whole WiFi waveband

Abstract

The WiFi technology has become a world-wide everyday service, and the accompanying electromagnetic pollution has attracted more and more attentions. This paper presents a transparent and flexible broadband metamaterial absorber (MMA) covering the whole WiFi waveband. The transparent and conducting material Indium Tin Oxide (ITO) was used for both the frequency select surface and the backplane ground layer, and polydimethylsiloxane (PDMS) was used as the dielectric layer for the microwave MMA. The absorber featured >80% absorption covering a wide frequency range of (2.2-5.85) GHz, which includes all the frequency bands of WiFi signal. The absorber was insensitive to the polarization angles and dropped little for incident angles less than 30°. Signal shielding experiments in 2.4 GHz and 5 GHz were carried out to demonstrate the application potential of the absorber. With additional advantages of optical transparency and mechanical flexibility, the broadband MMA can be useful in WiFi related applications in the future.

WiFi Signal Strength Degradation Over Different Building Materials

“…We can do several ways to increase the strength of the WiFi signal, one of which is to use an aluminium reflector that is focused in one direction (Gorade, S., et al, 2018). But it is also good if we avoid factors that can reduce the strength of WiFi signals, such as (1) human activity (Damodaran, N., et al, 2020;Thewan, T., et al, 2019), (2) electromagnetic waves (Valadares, D. C., et al, 2020), (3) magnetic fields (Wu, Y., et al, 2019), (4) distance between signal transmitter and receiver (Brinkhoff, J. & Hornbuckle, J., 2018;Zhang, S., et al, 2018), ( 5) water (Mei, X. et al, 2020).…”

High‐Performance Transparent Broadband Microwave Absorbers

“…[ 18–20 ] Meanwhile, various schemes based on patterned indium tin oxide (ITO) or other transparent conducting film structures have demonstrated the capability to broaden the microwave absorption by rationally designing resonant modes with different unit cells. [ 21–23 ] These artificial structures require complicated fabrication procedures involving multiple steps of photolithography and etching, and the low visible transparency of the ground layer further hinders their optical applications.…”

Transparent metamaterial absorber with broadband radar cross‐section (RCS) reduction for solar arrays

“…With the development of metamaterial absorbers (MMAs), several researchers were enlightened by the electromagnetic properties of water to design a novel metamaterial microwave absorber with a composite water-based structure based on random distribution [18,19], which can achieve a variable absorption band. Furthermore, the ground metal plate was also replaced by the transparent conductive film, enabling the absorber to be used in window applications [20][21][22][23]. To realize lightweight, low profile and wideband, a series of MMAs are proposed [24,25].…”