X-band composite microwave absorber using doped strontium ferrite

Abstract

In this work, cobalt and aluminium doped strontium ferrite nanoparticles (SrCo _x Al _y Fe _12-x-y O ₁₉ , x=0.8, y=3) are used as inclusions in Linear Low Density Polyethylene (LLDPE) matrix to develop a composite. SrCo _x Al _y Fe _12-x-y O ₁₉ is prepared at an annealing temperature of 950°C. The microstructural studies of the powder as well as the composite are conducted on SrCo _x Al _y Fe _12-x-y O ₁₉ . The complex permittivity and complex permeability is measured at X-band. Reflection loss of SrCo _x Al _y Fe _12-x-y O ₁₉ /LLDPE composite is determined using transmission line modelling (TLM) from the measured permittivity and permeability values. Thickness optimization carried out for the same sample from i mm to 4 mm, showed maximum reflection loss for 3 mm thickness and -10 dB bandwidth (i.e. 90% absorption) over the whole band.