Metasurfaces: physics and applications in wireless communications

The ever increasing number of wireless devices and systems has led to a crowded spectrum and increased the demand for versatile and multi-functional wireless apparatuses. Recently, metasurfaces have been explored as a prominent technological solution to the current paradigm of spectrum scarcity by opportunistically sharing the spectrum with various users. In general, metasurfaces are passive/dynamic, ultra-compact, multi-functional and programmable structures that are capable of both reciprocal and nonreciprocal signal-wave transmissions. The controllability and programmability of such metasurfaces are governed through DC bias and occasionally a radio-frequency modulation applied to the active components of the unit cells of the metasurface, e.g. diodes and transistors. This article overviews some of the recently proposed passive and dynamic metasurfaces and shows that metasurfaces can enhance the performance of wireless communication systems thanks to their unique physical features such as real-time signal coding, nonreciprocal-beam radiation, nonreciprocal beamsteering amplification and advanced pattern-coding multiple access communication. Metasurfaces can enable faster and more reliable wireless communications in the future through their emerging capabilities to effectively manipulate electromagnetic waves in space and time.

Automated summary

The increasing number of wireless devices has led to a crowded spectrum and increased demand for versatile wireless apparatuses. Metasurfaces have emerged as a technological solution to the spectrum scarcity problem by opportunistically sharing the spectrum. This article overviews passive and dynamic metasurfaces and shows their potential to enhance wireless communication systems through real-time signal coding, nonreciprocal beam radiation, nonreciprocal beamsteering amplification, and advanced pattern-coding multiple access communication.