Masters Theses

Abstract

Modern high-frequency measurement systems require reliable calibration and sample positioning to ensure measurement fidelity. This thesis presents three studies addressing practical limitations in broadband material parameter extraction and instrumentation.

The first study introduces a modified Nicolson–Ross–Weir (NRW) technique for flexible, compression-sensitive materials from 100 MHz to 18 GHz. Rigid 3D-printed spacers ensure precise sample positioning, and a T-matrix–based de-embedding procedure removes spacer effects. Validation using microstrip measurements and full-wave simulation confirms accurate permittivity extraction across compression levels.

The second study extends NRW to sheet materials enabling accurate material characterization. Independent validation using toroidal inductors with leakage correction and parallel-plate capacitors shows strong agreement, while also indicating anisotropic behavior in certain materials.

The third study presents a broadband technique for characterizing low-loss liquids using a coaxial structure. An eigenvalue-based 2x-thru de-embedding method, combined with attenuation correction, enables accurate extraction of dielectric constant and loss tangent from 100 kHz to 18 GHz, with sensitivity to loss tangents as low as 0.001. Results show excellent agreement with cavity resonator measurements.

Together, these contributions enhance the accuracy and robustness of broadband electromagnetic material characterization and probe calibration for flexible, planar, and electrically challenging measurement scenarios.

Advisor(s)

Khilkevich, Victor

Committee Member(s)

Commerou, Daniel
Beetner, Daryl G.

Department(s)

Electrical and Computer Engineering

Degree Name

M.S. in Electrical Engineering

Publisher

Missouri University of Science and Technology

Publication Date

Spring 2026

Journal article titles appearing in thesis/dissertation

Paper I, found on pages 4-17, Broadband Characterization of Flexible Material Using a Coaxial Structure will be published (2026 IEEE Internation Symposium on EMC+SIPI)

Paper II, found on pages 18-37, Sheet Material Characterization will be submitted to an undetermined conference.

Paper III, found on pages 38-50, Liquid Material Characterization will be submitted to an undetermined conference.

Pagination

xii, 55 pages

Note about bibliography

Includes_bibliographical_references_(page 53)

Rights

© 2026 Joseph Christopher Stecher , All Rights Reserved

Document Type

Thesis - Open Access

File Type

text

Language

English

Thesis Number

T 12608

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