Volume Fraction Sensing of Multivariable Systems using Multi-Resonances of Planar Microwave Resonators

  • Author / Creator
    Navid Hosseini
  • In recent years, sensing and selectivity have been the subject of many types of research due to their practical challenges. The main issue is the limited number of output data that confine the degree of freedom to solve the unknown problem. The majority of multi-variable experiments seek more assisting parameters and independent features for finalizing their solution. Microwave resonators as detecting devices can help gather the required data from the material under test in different experiments. Their resonance shift is one of the features that is mainly utilized for sensing purposes. But, for the detection of multi-variable parameters like multi-subcomponent volumes in a solvent or mixture, more than one independent feature is required. For overcoming this bottleneck, a new material characteristic is required, generating and defining the new independent features. Having more independent features out of the sensor response enables unknown variables identification. In this thesis, the term “harmonic” represents the resonance modes of the microwave resonator. One of the simplest forms of microwave resonators is the split ring resonator (SRR) and ring resonators. These kinds of structures are low-cost, non-invasive, and real-time devices making them a proper candidate for sensing applications. Like any other resonator, their microwave profile can be easily perturbed by introducing the external load and altering their Q-factor as a result. Generally, the rings are resonating structures that generate multiple resonant modes in their frequency response. These resonant mode frequencies are dependent features of the rings as they iterate themselves and their operational band. To make these elements change uniquely and independently, the variant permittivity profile of the materials under test can be considered as a new parameter. Developing the frequency shift of the resonances as a function of real relative permittivity variations defines the multiple independent features and authorizes the multi-variable diagnosis along with material senses. This can be realized by forming the linear system of equations for each independent resonant mode and solving them for volumetric unknowns or sub-component concentrations.

  • Subjects / Keywords
  • Graduation date
    Fall 2021
  • Type of Item
  • Degree
    Doctor of Philosophy
  • DOI
  • License
    This thesis is made available by the University of Alberta Libraries with permission of the copyright owner solely for non-commercial purposes. This thesis, or any portion thereof, may not otherwise be copied or reproduced without the written consent of the copyright owner, except to the extent permitted by Canadian copyright law.