Microwave Absorbing Properties of M-type Barium Ferrites with BaTi0.5Co0.5Fe11O19 Composition in Ka-band Frequencies

Magnetic and Ka-band absorbing properties have been investigated in Ti-Co substituted M-type barium hexaferrites with BaTi0.5Co0.5Fe11O19 composition. The ferrite powders were prepared by conventional ceramic processing technique and used as absorbent fillers in ferrite-rubber composites. The magnetic properties were measured by vibrating sample magnetometer. The complex permeability and dielectric constant were measured by using the WR-28 rectangular waveguide and network analyzer in the frequency range 26.5 similar to 40 GHz. For the Ti-Co substituted M-hexaferrites, the ferromagnetic resonance is observed at Ka-band (29.4 GHz). The matching frequency and matching thickness are determined by using the solution map of impedance matching. A wide band microwave absorbance is predicted with controlled ferrite volume fraction and absorber thickness.