Dielectric measurements on substrate materials at microwave frequencies using a cavity perturbation technique

TLDR

The paper presents a cavity perturbation resonance technique for measuring dielectric properties of substrate materials at microwave frequencies. The method uses thin rectangular samples inserted into a high‑Q rectangular waveguide cavity, with measurements taken at five frequencies using advanced microwave equipment. Measurements achieved ±2 % accuracy for dielectric constant and 3 × 10⁻⁴ for loss, with results presented for alumina and specially prepared silica between 8.2 and 12.4 GHz.

Abstract

A cavity perturbation resonance technique suitable for microwave measurements on substrate materials is discussed. The technique makes use of thin rectangular samples placed in a rectangular waveguide cavity (Q∼5000). The availability of advanced microwave measurement equipment makes it possible to record experimental data at several frequencies (five in this present case). The estimated accuracy of measurements is ±2% for dielectric constant and 3×10−4 for dielectric loss. Results are reported in the 8.2–12.4-GHz frequency range for alumina and specially prepared silica.