Miniature chips use sound and light to improve Wireless communications

For current and future wireless communication networks, various beams would need to be steered from one user to another using the concept of phased array antennas. These typically require multiple antennas with elements known as phase shifters. However, as the required bandwidth, and frequencies of operation rises, current electronic phase shifters cannot keep up with the required demands.

Prof Amol Choudhary from the Department of Electrical Engineering at the Indian Institute of Technology Delhi, in collaboration with Researchers at the University of Sydney, University of Twente and industrial partners have used optical techniques to demonstrate phase shifters over wide bandwidth using low optical powers.

The advantage of using optics for wireless communications rather than using conventional electronics is the inherent massive bandwidth that optics delivers, low losses and immunity to electromagnetic interference. This broader area of research known as microwave photonics is getting increasingly important, considering that the consumer’s requirement for bandwidth is rising.

They demonstrated a compact photonic chip that manipulates sound waves to perform phase shifting. This ultracompact and low-power phase shifter can have applications in phased array antennas, that for modern communication systems including 5th Generation (5G) networks, satellite communications, RADARs, sensing and medical imaging.

This device was realized on silicon, the most common platform for microelectronics and also an important photonic material, thus having the capability for low-cost mass-production. An optical process known as stimulated Brillouin scattering was used in the silicon device to create sound waves using intense light beams. This light-sound interaction creates a phase shift which is imparted to the applied electrical signal, thus generating a phase shift. The researchers also use a novel power-efficient scheme that delivers a full 360-degree phase shift making such a device very exciting for real-life applications.

Prof Choudhary said, “This is an exciting result since we use the interaction of light and sound in a material to demonstrate results that are important for wireless communication applications, thus combining 3 diverse areas of research to solve a real-life problem.”

Prof Choudhary said, “This is an exciting result since we use the interaction of light and sound in a material to demonstrate results that are important for wireless communication applications, thus combining 3 diverse areas of research to solve a real-life problem.”

This paper was recently published in the Optical Society (OSA) ‘s high-impact journal Optica.

https://www.osapublishing.org/optica/abstract.cfm?uri=optica-6-7-907

This paper was recently published in the Optical Society (OSA) ‘s high-impact journal Optica.

9th Oct, 2019