High-accuracy quasistatic numerical model for bodies of revolution tailored for RF measurements of dielectric parameters

Abstract

We have developed rotationally symmetrical coaxial chambers for measurements of dielectric parameters of disk-shaped samples, in the frequency range from 1 MHz to several hundred MHz. The reflection coefficient of the chamber is measured and the dielectric parameters are hence extracted utilizing a high-accuracy quasistatic numerical model of the chamber and the sample. We present this model, which is based on the method of-moments solution of a set of integral equations for composite metallic and dielectric bodies. The equations are tailored to bodies of revolution. The model is efficient and accurate so that the major contribution of the measurement uncertainty comes from the measurement hardware.

High-Precision Method of Moments Applied to Measurement of Dielectric Parameters at Microwave Frequencies

“…We use a custom-made coaxial chamber [27] for permittivity measurements. The first step is to measure the reflection coefficient of the chamber with the sample placed inside it.…”

“…We use an upgraded version of the coaxial chamber from [26], for which the material samples need to be disk-shaped. Previous quasistatic models of the chamber [27] were used for measurements of ceramic samples [28] at lower frequencies, up to 1000 MHz, while the proposed approach significantly increases the upper frequency limit, deeply into the microwave region.…”