Dependence of microwave absorption properties on ferrite volume fraction in MnZn ferrite/rubber radar absorbing materials

TL;DR

This study investigates how varying the ferrite volume fraction in rubber-based radar absorbing materials affects their microwave absorption properties across 2 to 18 GHz, highlighting the importance of composition and thickness for optimal absorption.

Contribution

It provides a detailed analysis of how ferrite content influences the electromagnetic properties and absorption performance of rubber RAM, offering guidelines for material optimization.

Findings

Higher ferrite volume fraction increases permeability and permittivity spectra.

Optimal microwave absorption depends on both material composition and thickness.

Reflection loss is significantly affected by impedance matching conditions.

Abstract

We report the analysis of measurements of the complex magnetic permeability ($\mu_r$) and dielectric permittivity ($\epsilon_r$) spectra of a rubber radar absorbing material (RAM) with various MnZn ferrite volume fractions. The transmission/reflection measurements were carried out in a vector network analyzer. Optimum conditions for the maximum microwave absorption were determined by substituting the complex permeability and permittivity in the impedance matching equation. Both the MnZn ferrite content and the RAM thickness effects on the microwave absorption properties, in the frequency range of 2 to 18 GHz, were evaluated. The results show that the complex permeability and permittivity spectra of the RAM increase directly with the ferrite volume fraction. Reflection loss calculations by the impedance matching degree (reflection coefficient) show the dependence of this parameter on both thickness and composition of RAM.