Measuring Dielectrics Using Shielded Loop Antennas

abstract: This work is concerned with the use of shielded loop antennas to measure permittivity as a low-cost alternative to expensive probe-based systems for biological tissues and surrogates. Beginning with the development of a model for simulation, the shielded loop was characterized. Follo...

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Bibliographic Details
Other Authors: Yiin, Nathan (Author)
Format: Dissertation
Language:English
Published: 2018
Subjects:
Online Access:http://hdl.handle.net/2286/R.I.49213
Description
Summary:abstract: This work is concerned with the use of shielded loop antennas to measure permittivity as a low-cost alternative to expensive probe-based systems for biological tissues and surrogates. Beginning with the development of a model for simulation, the shielded loop was characterized. Following the simulations, the shielded loop was tested in free space and while holding a cup of water. The results were then compared. Because the physical measurements and the simulation results did not line up, simulation results were forgone. The shielded loop antenna was then used to measure a set of NaCl saline solutions with varying molarities. This measurement was used as a calibration set, and the results were analyzed. By taking the peak magnitude of the input impedance of each solution, a trend was created for the molarities. Following this measurement and analysis, a set of unknown solutions was tested. Based on the measurements and the empirical trends from the calibration set of measurements, the molarities of the valid unknown solutions were estimated. It is shown that using the known molarities, permittivity can also be calculated. Using the estimated molarities of the unknown solutions, the permittivity of each solution was calculated. The maximum error for the estimation was 1.07% from the actual data. === Dissertation/Thesis === Masters Thesis Electrical Engineering 2018