Applications of Embedded Metamaterial-Based Electromagnetic-Bandgap Structures for Dual-Band Devices and Compact Tunable Bandstop Filtering

• Applications of Embedded MTM-EBG for Dual-Band Devices and Compact Tunable Bandstop Filtering

• Author / Creator

  Brown, Jacob A.

• While dual-band devices and filters are used for different applications, they each rely on a resonance mechanism. At high frequencies, where discrete lumped elements becomes unreliable, these resonances are introduced through electrical long transmission line (TL) segments. Metamaterials (MTMs), such as the negative-refractive-index transmission line (NRI-TL), can realize the same behavior while being directly embedded in a microstrip (MS) TL, thereby offering a high degree of miniaturization. A recently proposed MTM-based structure, known as the metamaterial-based electromagnetic bandgap structure (MTM-EBG), can realize many of the same dual-band and filtering properties, while being realized in a fully planar, fully printable and highly compact manner. The MTM-EBG relies on the interaction between a conventional right-handed MS-like mode and a left-handed coplanar waveguide
  (CPW)-like mode to realize a strong bandgap. This bandgap is predictable using multi-conductor transmission line (MTL) theory, and has consistent results with full-wave simulations. Here the MTM-EBG is analyzed for use in a fully embedded
  manner; this means that it can be directly inserted into an existing trace of MS, without occupying substantially more, if any, area. This fully embedded, uniplanar and printed device is used to develop a host of dual-band devices, including impedance transformers and power dividers. These are extended into the development of a dual-band corporate feed network, which can be easily augmented with dual-band
  radiating elements for a full dual-band antenna array. While developing these dual-band devices, it was identified that the MTM-EBG displayed a substantial amount of rejection given its diminutive footprint. These properties led to the development
  of a fully planar MTM-EBG-based MS bandstop filter, and the development of a new tuning mechanism perfectly suited to the MTM-EBG. By varying the position of a dielectric plate placed
  ush to the interdigitated capacitors of a fully printed
  MTM-EBG, the rejection band may be shifted by an amount proportional to the permittivity of the plate.

• Subjects / Keywords

  • tunable filters
  • dual-band devices
  • multi-conductor transmission lines
  • metamaterials

• Graduation date

  Spring 2020

• Type of Item

  Thesis

• Degree

  Master of Science

• DOI

  https://doi.org/10.7939/r3-edzj-dm17

• License

  Permission is hereby granted to the University of Alberta Libraries to reproduce single copies of this thesis and to lend or sell such copies for private, scholarly or scientific research purposes only. Where the thesis is converted to, or otherwise made available in digital form, the University of Alberta will advise potential users of the thesis of these terms. The author reserves all other publication and other rights in association with the copyright in the thesis and, except as herein before provided, neither the thesis nor any substantial portion thereof may be printed or otherwise reproduced in any material form whatsoever without the author's prior written permission.