LAUSR

Abstract In order to achieve a broad bandwidth absorber at high frequency, the composites of M-type ferrite BaCo 1.0 Ti 1.0 Fe 10 O 19 (BaM) with flaked carbonyl iron powders (CIP) and flaked Fe 50 Ni 50 were prepared to optimize the surface impedance in broadband frequency, respectively. The diameter of the flaked carbonyl iron powders (CIP) and Fe 50 Ni 50 is in the range of 5–10 µm and 10–20 µm and the thickness of the CIP and Fe 50 Ni 50 is close to 200 nm and 400 nm, respectively. The complex permeability and permittivity show that the addition of BaM obviously reduces the values of real part of permittivity and imaginary part of the permeability which can enhance the matched-wave-impedance. The absorption bands less than −10 dB of CIP-BaM and FeNi-BaM absorber approach to 5.5 GHz (5.7–11.2 GHz) and 7 GHz (11–18 GHz) at 1.5 mm. However, the bands of CIP and FeNi are only 1.9 GHz (4.7–6.6 GHz) and 2.1 GHz (4.0–6.1 GHz). Hence, the electromagnetic match property is greatly improved by BaM ferrites, and this composite shows a broaden absorption band.