Fabrications of broad-band RF-absorber composed of planar hexagonal ferrites

Abstract

Single-layer absorbers composed of sintered planar hexagonal ferrites were developed. The absorbers have 50/spl sim/90% relative bandwidth at microwave frequencies. The broadband characteristics were successfully analyzed by a quarter-wavelength resonator model, which took into account both a wavelength reduction due to 1//spl radic/(/spl epsiv//sub r//spl mu//sub r/) and a resonant frequency shift depending on tan /spl delta//sub /spl mu//, where /spl epsiv//sub r/ and /spl mu//sub r/ are relative permittivity and permeability, respectively, for the resonator material.