Christopher Merola, a PhD student of Associate Professor Marinos Vouvakis, won the Best Student Paper Award at the 2019 Institute of Electrical and Electronics Engineers (IEEE) Phased Arrays Systems and Technology conference (http://array2019.org/). His paper was entitled: “An RF beamforming Architecture for UWB continuous Time-Delay Control” by Merola and Vouvakis. The conference was held from October 15 to 18 in Waltham, Massachusetts. See Merola’s winning poster: https://drive.google.com/a/umass.edu/file/d/1sk9YTEYYjN_9kzU_YeOy7Wp_kIAW-gfG/view?usp=drive_web;
As Merola explains the practical relevance of his groundbreaking paper: “This work presents a simple, efficient, low-cost network for rapid and precise scanning of a broadband signal; for example, when communicating with Low-Earth-Orbit satellites in proposed high-speed, low-latency Internet links (such as Project Kuiper, Starlink, OneWeb, Telesat LEO).”
Merola says that in his winning paper, “A radio frequency beamforming architecture is proposed that provides ultra-wideband continuous true-time delay for timed array beam-steering.”
According to Merola, the elegant architecture relies on a unique Rotman lens multi-beamformer core and a simple electronic network consisting of a few power dividers, switches, and variable attenuators (or amplifiers), which are responsible for moving the beam-port phase center around the lens beam arc.
“This continuous movement,” says Merola, “is translated into true-time-delay control at the array ports by the optics of the lens.”
As Merola says, describing the background of his paper, electronic scanned arrays rely on beamforming hardware to provide precise time delays between element excitations. Varying these time delays has the effect of changing the direction in which the signals add coherence and result in beam-steering. Various approaches for realizing this time delay network can be employed.
“In terms of space, weight, power, and cost, each approach offers advantages and shortcomings that depend on application-specific metrics such as dynamic range, bandwidth, frequency range, to name a few,” says Merola. “Radio frequency beamforming is favored for electronic scanned arrays deployments in interference-rich or jammer-rich environments….”
Merola observes that his “proposed beamforming architecture offers continuous wideband true-time delay without resorting to tunable materials or loaded delay-lines. Instead, it relies on a novel ultra-wideband Rotman lens multi-beamformer core and a few passive electronics, such as power dividers, switches, and attenuators, for beam-steering control. The network converts amplitude weighting, which is easy, into true-time delay, which is hard.”
Merola was also the winner of the 2018 IEEE Antennas and Propagation Society Student Paper competition at the 2018 IEEE International Symposium on Antennas and Propagation and USNC-URSI Radio Science Meeting in Boston. Merola’s winning 2018 paper was titled, “A Class of Cavity-Based UWB Multi-Beamformers with Applications to Sub-6 GHz 5G,” and his advisor was also Vouvakis. See Merola’s poster summarizing his 2018npaper: https://drive.google.com/open?id=1haMJ6d21U8cpeqfb-3Ky95r9E4nTpmN7.