Broadband microwave absorber using M-type hexagonal ferrite

The microwave absorption properties of M-type hexagonal ferrite BaFe/sub 12-X/(Ti/sub 0.5/Mn/sub 0.5/)/sub X/O/sub 19/ composite have been investigated. It was found that the complex permeability and /spl mu/'/sub r/ and /spl mu/"/sub r/ induced by the ferrimagnetic resonance can be controlled both in amplitude and along the frequency axis by changing the substitution amount x and the powder mixture ratio. The complex permeability of TiMn substituted ferrite composite was successfully adjusted to the calculated absorption condition, and exhibited a wide absorption bandwidth /spl Delta/f/f=47% in the X-band with a homogeneous single-layer configuration. The mixture of two kinds of ferrite powder exhibited a wider bandwidth of 53% and a simulated model indicates that it should be possible to obtain a further increase.