Phase-ambiguity-free and accurate permittivity determination from waveguide measurements

Area of Science:

• Materials Science
• Electromagnetics
• Microwave Engineering

Background:

• Accurate characterization of dielectric material properties is crucial for microwave applications.
• Traditional methods for measuring complex permittivity (εr) can be complex and prone to phase ambiguity.
• Scattering parameter (S-parameter) measurements are a standard technique in microwave engineering.

Purpose of the Study:

• To develop and validate a novel microwave method for precise extraction of relative complex permittivity (εr).
• To address the challenge of 2π phase ambiguity in dielectric measurements.
• To demonstrate the method's applicability to both low-loss and lossy dielectric materials.

Main Methods:

• Proposed a microwave measurement technique utilizing amplitude-only, two-port, and one-port scattering parameter data.
• Implemented an uncertainty analysis to quantify and improve the accuracy of the extracted permittivity values.
• Validated the method by measuring the εr of well-characterized low-loss and lossy dielectric samples.

Main Results:

• Successfully extracted the relative complex permittivity (εr) of dielectric materials with high accuracy.
• Demonstrated the 2π phase-ambiguity-free nature of the proposed method.
• Confirmed the method's effectiveness for both low-loss and lossy materials through experimental validation.

Conclusions:

• The developed microwave method provides an accurate and unique way to determine dielectric material complex permittivity.
• The technique effectively resolves 2π phase ambiguity using only amplitude-only S-parameter measurements.
• This approach offers a reliable tool for material characterization in microwave engineering and related fields.