Magneto-dielectric material with nano ferrite inclusion for microstrip antennas: dielectric characterization

Magneto dielectric material using nano cobalt ferrite inclusions is prepared as potential substrate for microstrip antennas. Permittivity characterization at microwave frequency (8.7- 12.1 GHz) is conducted using an in touch superstrate method. Test set-up consists of microstrip antenna designed over glass epoxy substrate and loaded with the test samples of different volume fraction of inclusions. The real part of complex permittivity increases with volume fraction for different magneto dielectric material. The dielectric loss is found in the order of 10^-3. Morphological characterizations like scanning electron microscopy and X-ray diffraction carried out on the test materials show homogeneous distribution of the inclusions in the composite and the size of the inclusions is found to be ~10 nm. With minor mathematical manipulations the method can be used to design antennas with dielectric cover at specific operating frequency.