Design of Aperiodic Electromagnetic Bandgap Structures using Quasi-analytic Solutions

Open Access
Author:
Martin, Spencer Harris
Graduate Program:
Electrical Engineering
Degree:
Master of Science
Document Type:
Master Thesis
Date of Defense:
June 28, 2012
Committee Members:
  • Douglas Henry Werner, Thesis Advisor
  • Pingjuan Li Werner, Thesis Advisor
Keywords:
  • Electromagnetic bandgap
  • Aperiodic
  • Capacitively Loaded
  • CMAES
Abstract:
This work examines electromagnetic band gap (EBG) structures and several meth- ods of modifying the basic properties of them. Specifically, a method is presented that allows for the design of aperiodic electromagnetic bandgap structures, which can target a wide range of objectives. This aperiodicity is achieved by adding capacitive loading to the original underlying structure. To propererly select the appropriate loading needed, the covariance matrix adaptation evolutionary strat- egy (CMAES) is employed to search for the best set of capacitive loads. In order to make this a practical solution, the optimization is aided by a fast port reduc- tion strategy. This method replaces time consuming full-wave simulations with a fast quasi-analytic solution that is extremely accurate. Several examples of this method in practice are also presented, which include several test environments and design goals. Furthermore, methods to implement additional capacitive loading, when lumped elements are not an option, are also considered. The final result is a systematic design methodology for creating a diverse set of EBG structures for a wide range of target applications.