Publication – Ultra-Wideband Textile-Based Metamaterial Absorber for mm-wave Band energy harvesting applications

Outline the paper

The absorber is a radio frequency circuit that is utilized to absorb electromagnetic waves when it impinges its surface. They are used extensively in energy harvesting, infrared camouflage and sensors applications. The merits of the absorber are its operation band width and absorption coefficient. Conventional absorbers use normal substrates such as FR4 material. These traditional absorbers suffer from low operation bandwidth and small absorption coefficient. Moreover, they do not work effectively in the ever-growing mmWave band. Furthermore, there is a need to build flexible absorbers to be used, for example, in the context of wearable sensors. The designed circuit harnesses left handed material to build a higher performance metamaterial absorber to work in the mm Wave band.

This work presents a state-of-the-art development of an ultrawide absorber for wearable smart electronic textile applications. The design is based on a novel cell geometry that was previously developed and applied to RF energy harvesting applications. Different textile types were considered in this study, including Felt, Denim and Polyester, and the achieved -10 dB reflective fractional bandwidths were about 42.828%, 43.65%, and 42.834% respectively.  Compared to traditional absorbers, this new absorber is lighter, more compact, and more efficient in terms of absorptivity. The current results can be considered as initial promising steps for the development of ultra-wideband electronic textiles-based applications such as energy harvesting, health monitoring, smart materials, sensors, and infrared camouflage.

Who will it help?

Smart electronic textiles are being continuously integrated in the services ecosystem, and is a very promising sector which requires the development of light, efficient and flexible system components. Powering smart wearable electronics and sensors usually requires batteries which poses several constraints on the system. Energy self-consistent systems, including their sustainability and impact on the environment, is another important aspect of wearable electronics, which still requires more research and development. In order to overcome the need for batteries, harvesting energy from radio frequency (RF) resources shows promising green, alternative energy sources for low power consumption systems and for smart textile-based applications. Absorbers are used in energy harvesting systems, therefore the development of a high performance absorber is a truly great achievement for this.

What is the future of this research?

The next steps in this research are:

• Further enhance the bandwidth and absorption coefficient.
• Increase the operation frequency for higher bands to be able to absorb more power from for instance 6G network.
• Trialing different textiles to optimize performance.
• Trialing different unit cells shapes to minimize the circuit footprint.

Publication Title: Development of Ultra-Wideband Textile-Based Metamaterial Absorber for mm-wave Band Applications
Authors: Gökberk Akarsu, Hany Taher , E. Buse Zengin, Mohammed Farouk Nakmouche, A.M.M.A Allam, Diaa E. Fawzy, Frances Cleary  
Publication Date: 27^th March – 1st April
Conference: 16th European Conference on Antennas and Propagation (EurAAP 2022)