Shape-Changing Phased Arrays

Author: Williams, David Elliott

Year: 2022

Degree: Dissertation (Ph.D.)

Advisor: Hajimiri, Ali

Committee Members: Emami, Azita; Bhattacharya, Kaushik; Weinreb, Sander; Hajimiri, Ali

Option: Electrical Engineering

DOI: 10.7907/r6f1-zq65

Abstract

Historically, increasing the degrees of freedom in electromagnetic structures has revolutionized the capabilities of wireless systems and introduced new applications. While research on phased arrays has explored everything from antenna drive settings to the element placement, the array geometry is assumed to be a fixed parameter. This thesis summarizes the author's work developing shape-changing phased arrays. It demonstrates the fundamental trade-off between gain and steering range for a given geometry. Measurements of the first shape-changing phased array both verify this theory and demonstrate the ability to break this trade-off using geometric reconfiguration. In addition, the mathematical consequences of shape-change and their impact on the arrays electromagnetic properties are discussed. Programmable passive switching networks on flexible sheets embedded in the array are proposed to address these challenges. The ability of these structures to enhance array performance is demonstrated by in-situ optimization experiments on a demonstration array. The associated optimization problem is characterized with a statistical analysis on a simulated array. Finally, avenues for further research are proposed.

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