Bandstop Passive Filter Characteristics of Hexagonal Ferrite Composites at X-Band


In wireless communication, filters are incorporated to allow/stop the desired range of frequencies depending upon the application. The composites of M-type hexagonal ferrite Ba0.5Sr0.5CoxTixFe12-2xO19 and Polyaniline (PANI) have been prepared with the volume fraction of 30:70 percent. Composite samples were fitted at one end of the rectangular waveguide and a vector network analyzer was interfaced with two ports of rectangular waveguide. The microwave characteristics of composite samples were measured from 8.2 GHz to 12.4 GHz by a vector network analyzer with the help of scattering parameters. The dielectric loss tangent was found to be more than magnetic loss tangent in all compositions. The doping of Co2+-Ti4+ ions and good electrical conductivity of PANI altogether increased attenuation in the microwave signal. Composition x = 0.6, 0.8 and 1.0 have − 10 dB bandstop bandwidth of 4.2 GHz covering the whole investigated frequency band, while composition x = 0.8 and 1.0 exhibited a rapid rate of fall in attenuation after 10 GHz. Composition x = 0.8 has maximum attenuation of − 40.9 dB at 12.4 GHz. The results suggest that prepared compositions can be useful for wideband bandstop passive filter application.

Publication Title

Journal of Electronic Materials