C. McKeever
NanoCom Inc.,
United States
Keywords: magnetodielectric composites, computational electromagnetics, multiresonance, effective permeability, effective permittivity, microwave frequencies
Summary:
Magnetodielectric composite materials are increasingly used in microwave-frequency electromagnetic systems, including compact antennas, radar absorbers, and electromagnetic compatibility (EMC) structures. Their performance is governed by strongly frequency-dependent effective permeability and permittivity arising from complex magnetic and dielectric interactions at the micro- and nanoscale. Accurate numerical prediction of these properties remains challenging for conventional full-wave solvers due to numerical dispersion, stability constraints, and limited support for nonlinear and dispersive magnetic material models. This presentation describes recent advances in a rapid, time-domain electromagnetic simulation framework for modeling magnetodielectric composites at microwave frequencies. The approach employs an efficient, unconditionally stable CrankâNicolson formulation coupled with magnetic material dynamics, enabling efficient full-wave simulation across broad frequency bands without restrictive timestep constraints, with improved numerical dispersion characteristics compared with standard FDTD approaches. Simulation results show strong agreement with experimental measurements of frequency-dependent permeability for representative magnetodielectric composite systems. In particular, the model accurately reproduces multiple magnetic resonance phenomena observed experimentally, including broadening of the ferromagnetic resonance (FMR) response and the emergence of overlapping and higher-order resonances that play a critical role in broadband microwave behavior. These multiresonant effects are captured directly within the time-domain formulation without reliance on empirical fitting or simplified homogenization assumptions. Beyond field-level validation, the framework enables direct extraction of effective material parameters from transient simulation data. Both effective permeability and effective permittivity are computed, providing a quantitative link between microscopic composite structure and macroscopic electromagnetic response. This capability supports predictive material design and direct comparison with experimental characterization. The rapid simulation capability enables practical modeling of complex composite geometries and parameter sweeps that are otherwise computationally prohibitive using conventional solvers. Overall, the results demonstrate that advanced time-domain simulation techniques can efficiently and accurately capture the multiresonant microwave behavior of magnetodielectric composites, supporting simulation-driven development of next-generation microwave materials and devices. http://nanocomx.com