Microwave absorbing characteristics in Ba-Co-Ti & Sr-Mn-Ti hexaferrite

The investigation of microwave absorption characteristics for M-type Ba-Co-Ti and Sr-Mn-Ti hexagonal ferrites is done as a function of substitution and frequency at X-band. The measurement of absorption characteristics has been done by an Absorbing Testing device (ATD) method and quarter wavelength criterion is used to evaluate absorption. In BaCoxTixFe(12-2x)O19 ferrite,x=0.9 exhibits maximum RL of -31.94 dB at 10.47 GHz. The compositions x=0.1, 0.5, 0.7 and 0.9 satisfy the quarter wavelength criterion (QWC)by matching the theoretical thickness 3.5 mm, 3.2 mm, 3.2 mm and 3.2 mm with the actual thickness 3.3 mm, 3.4 mm, 3.2 mm and 3.3 mm at matching frequencies 10.49 GHz, 9.27 GHz, 10.47 GHz and 10.47 GHz respectively. In SrMnxTixFe(12-2x)O19 ferrite, the composition x=0.5 exhibit good electromagnetic shield characteristics with 96.94% reflected power at 8.27 GHz. Compositions x=2.0 and x=1.5 show maximum RL of -14.68 dB and -12.16 dB at 12 GHz. Composition x=1.0 shows more than 90 % absorbed power at 9.53 GHz.The compositions x= 1.0, 1.5 and 2.0 with actual thickness 3.8, 3.4 and 2.3 mm, satisfy QWC (3.7, 3.3 and 2.3 mm) at 12 GHz.