Bismuth and Cobalt Multiphasic System: Synthesis and Application as Microstrip Patch Antenna Substrate

Sillenites have been a subject of increasing interest for electronics applications due to their unique crystal structure, ease of synthesis and vast potential for combination with other elements. In this study, bismuth-cobalt-based material is produced and applied as microstrip patch antenna (MPA) substrate. Synthesis, characterization, simulations and measurements are detailed. To produce Bi13Co11, a sol-gel technique modified by ionic coordination reaction (ICR) was performed, followed by calcination and sintering. Structural characterization was performed by x-ray diffraction, followed by Rietveld refinement, resulting in a main phase-weighted percentage of 53.82%, to which the magnetic property of the material was ascribed. Dielectric characterization from 1.0 GHz to 8.5 GHz presented real permittivity around 5.0 and dielectric loss tangent around 0.02. Material performance as substrate was evaluated through two microstrip patch antenna geometries. Reflection coefficient (S-11) measurements presented dual-band characteristics, good agreement with simulations and maximum resonance frequency error of 4.84%, validating characterizations. Directional behavior was observed through simulated radiation patterns. Efficiency ranged from 75% to 85% in all cases.