Microwave studies on strontium ferrite based absorbers

Single layer microwave absorbers based on strontium ferrite-epoxy composites have been fabricated and their reflection loss characteristics studied in the X-band (8-12.4 GHz) of microwave frequencies. Permittivity (is an element of'(r) - j is an element of(r)") and permeability (mu'(r) - jmu(r)") of Co and Ti added strontium ferrite SrCoxTixFe12-2xO19 (x = 0.1 to 0.9 in steps of 0.2), have been measured. Thickness of the absorber is an important criterion influencing the absorption characteristics. Composites of 3 mm thickness are found to absorb over a reasonable range of X-band frequencies. A minimum reflection loss of -36.5 dB is observed for the composite with x = 0.3.