(Bi13Co11)Co2O40–Co3O4 nanocomposites: Synthesis, characterization and application as substrate for microstrip patch antenna

Abstract The sillenite-cobaltite nanocomposites with chemical formula (Bi13Co11)Co2O40–Co3O4 were synthetized and characterized for application as substrate in a microstrip patch antenna. To prepare the sample, the combustion method using urea as fuel was applied. The structural and vibrational characterizations were done through X-ray diffraction and infrared spectroscopy. The morphology of the sample was studied through FESEM images. The magnetization as a function of magnetic field recorded at 300 K confirmed the paramagnetic character of the sample. Electric characterization was performed from 1.0 GHz to 8.5 GHz aiming a wide frequency spectrum data, presenting steady real relative permittivity around 7, with low losses as results. A microstrip patch antenna was designed by cavity method with the nanocomposite as substrate for application in X-band communication services. Reflection coefficient measurements displayed a good agreement with simulations, achieving only 0.39% error in resonance frequency, validating the performed morphological and electrical characterizations, as antenna design. Simulated radiation pattern is also presented, with coherent results for a directive device.