FLEXIBLE MICROWAVE ABSORBER BASED ON STRONTIUM FERRITE-RUBBER COMPOSITE FOR X-BAND APPLICATIONS

Abstract

Silicone rubber based composite with nano sizestrontium ferrite (SrFe 12 O 19 ) as inclusion have been fabricated with a view to develop high dielectric loss, flexible and thin single layer microwave absorbers and their reflection loss and microwave characterization were studied in the of microwave frequencies.M-type hexagonal strontium ferrite (SrFe 12 O 19 ) particles have been prepared from nitrate precursors using co-precipitation technique.The nano size of strontium ferrite is confirmed by XRD analysis.The complex Permittivity ( = / - // ) and permeability ( =  / - // ) of strontium ferrite (SrFe 12 O 19 ) have been measured for various weight fraction of the composite.Strontium ferrite when impregnated into the rubber matrix imparts the required complex dielectric permittivity and permeability to the composite.Thickness of the absorber is an important criterion influencing the absorber characteristics.Composites samples of 3.5mm and 4mm thickness are found to absorb over the whole X-band frequencies with -10 dB reflection loss.A minimum reflection loss (S 11 ) of -15 dB is observed for the composite with weight fraction 60 wt.% and = 0.2 (loss tangent, =