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Shape-Changing Phased Arrays


Williams, David Elliott (2022) Shape-Changing Phased Arrays. Dissertation (Ph.D.), California Institute of Technology. doi:10.7907/r6f1-zq65.


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.

Item Type:Thesis (Dissertation (Ph.D.))
Subject Keywords:Phased Arrays, Adaptive Arrays, Aperture, Patch Antennas, Flexible Electronics, Origami Antennas, Kirigami Antennas, RFIC, Integrated Circuits, Origami, Measurement Techniques, Metahueristics, Optimization, Simulated Annealing, Genetic Algorithms, Particle Swarm Optimization, Variable Neighborhood Search, Metamaterials.
Degree Grantor:California Institute of Technology
Division:Engineering and Applied Science
Major Option:Electrical Engineering
Thesis Availability:Public (worldwide access)
Research Advisor(s):
  • Hajimiri, Ali
Thesis Committee:
  • Emami, Azita (chair)
  • Bhattacharya, Kaushik
  • Weinreb, Sander
  • Hajimiri, Ali
Defense Date:7 June 2022
Non-Caltech Author Email:david.elliott.williams (AT)
Funding AgencyGrant Number
Air Force Office of Scientific Research (AFOSR)FA9550-16-1-0566
Record Number:CaltechTHESIS:03312022-192034489
Persistent URL:
Related URLs:
URLURL TypeDescription with content in Chapters 4, 6, and 7.
Williams, David Elliott0000-0002-6213-4712
Default Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:14536
Deposited By: David Williams
Deposited On:08 Jun 2022 15:26
Last Modified:15 Jun 2022 17:18

Thesis Files

[img] PDF (Shape-Changing Phased Arrays) - Final Version
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[img] PDF (First Generation Tile Schematic) - Supplemental Material
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[img] PDF (Second Generation Tile Schematic) - Supplemental Material
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[img] Archive (ZIP) (Source code for Meta-Gap Optimization) - Supplemental Material
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