Material Characterization Using the Clamped Circular Waveguide Method

This paper examines the clamped waveguide technique with circular waveguides for material characterization and nondestructive testing and evaluation. The clamped waveguide technique provides an alternative, non-destructive method to the filled waveguide technique, which is a destructive technique due to the sample shaping requirement. This technique is evaluated and proven effective by measuring and characterizing several materials with well-known electromagnetic material properties. Measurements are performed at 32–40 GHz, and the electro-magnetic material properties are calculated through an iterative curve fitting algorithm. Results show that this method effectively calculates the complex relative permittivity. However, this method struggles to accurately calculate the loss-factor of the relative complex permittivity for very low-loss materials.