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 W_P is significantly widened for the flaky-filler composites; W_P achieves 130%-150% for reflection loss RL <; -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^´(f) and ε^´(f) , where μ^´/ε^´=1/3 .