Enhanced Microwave Magnetic and Attenuation Properties for Barium Ferrite Flaky-Filler Composites

Microwave reflection characteristics as well as high frequency magnetic and dielectric properties have been studied for composites filled with Z-type barium ferrite flakes. Results show that both μ₀^' and μ_max^''are enhanced, while ε^' is almost the same, as compared to conventional composites. Therefore, the percentage bandwidth <i>W</i>_P is significantly widened for the flaky-filler composites; <i>W</i>_P achieves 130%-150% for reflection loss <i>RL</i> <; -10&nbsp;dB. In addition, for all composites, two matching frequencies are found. The first matching frequency is attributed to the quarter-wavelength resonator and the second matching frequency is mainly controlled by the values of both μ^'(<i>f</i>) and ε^'(<i>f</i>) , where μ^'/ε^'=1/3 .