Absorption frequency tuning with double layer ferrite stacks

This paper outlines the work accomplished to date on electromagnetic (EM) wave absorption in the television (TV) frequency range using thin, strong and weather-resistant absorbing tiles. The tiles are composed of multilayered stacks of ceramic materials. These materials include ferrites, signet magnetic, garnets, magneto resistive and dispersive materials. Several stacks using only two different materials in different orders were designed with a total thickness of approximately 6 mm for broad-band absorption. These simple two-layer stacks were modeled and simulated. Selected designs were fabricated, tested, and analyzed. The constitutive parameters (complex permittivity and permeability) of the materials in the individual stacks were measured as a function of frequency and the effective reflection coefficient of the composite two layer stack was simulated. The measured data and the simulation results for the individual experiments are presented.