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Cheng Qi-led Team wins 3rd Place Nokia Bell Labs Prize

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Nokia held a virtual awards ceremony on December 3 and announced the winners of the 2020 Bell Labs Prize, a competition that recognizes disruptive innovations that will define the next industrial revolution. Proposals were received from 208 academics in 26 countries, and a team from the Georgia Tech School of Electrical and Computer Engineering (ECE) consisting of GTPG member Cheng Qi, Francesco Amato, and Greg Durgin was presented with the third-place prize.  Read more here.

Motion Capture Through Walls, Long Distances

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Fine-scale Through-Wall Positioning Using Tunneling RFID Tags
Cheng Qi;Francesco Amato;Billy Kihei;Gregory D. Durgin
2020 IEEE International Conference on RFID (RFID)

It has been shown that Tunneling Tags enable long-range communications and localization in line-of-sight (LoS) with an RFID reader operating in the 5.8 GHz band. This paper demonstrates how a received signal phase-based positioning method can be applied to localize tags in a non-line-of-sight (NLoS) scenario. In particular, a Tunneling Tag provides 20.0 dB more received signal strength than a Semi-passive one when they communicate through a plaster wall. Moreover, when calibration is applied, average distance estimation accuracies of 12.1 cm (percentage error: 2.1%) and 9.2 cm (percentage error: 1.4%) are achieved in LoS and NLoS, respectively. The low-power requirement of the Tunneling Tag and the low EIRP of the reader suggest that these tags can significantly contribute to developing new and low-powered indoor positioning applications.

Foundational Paper on How to Model a Really Complicated Multi-Loop/Coil Inductive System

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Theoretical Modeling of Complicated Inductive Wireless Power Transfer Systems
Scott Roman, Gregory D. Durgin
2020 IEEE International Conference on RFID (RFID)

Inductive RF power transfer designs can be incredibly versatile, designed with a multiplicity of geometries and current paths to focus and enhance the transfer of power. However, most inductive systems in engineering practice are limited to either two-flat-loop systems or several basic coils with simplifying symmetry aspects. Complicated loop designs are largely ignored or untried by engineers because they are notoriously difficult to understand and model. This paper presents a foundational model for inductive systems with an arbitrarily large number of mutually-coupling loops. For the first time, comprehensive first-principle expressions for calculating voltage gain, s-parameters, and transfer efficiencies for these arbitrarily complicated inductive systems are presented and compared to measurements. The final result is a set of tools for designing the next-generation inductive RFID and wireless power transfer systems.