Dielectric characterisation and numerical investigation of SrBi₂Nb₂O₉–Bi₂O₃ composites for applications in microwave range

Abstract

We present a study of the dielectric properties and behaviour of dielectric resonator antennas (DRAs) based on SrBi₂Nb₂O₉ (SBN)-Bi₂O₃ composites. X-ray diffraction is used for structural characterisation of the samples and it indicates the formation of a new phase after the addition of Bi₂O₃. The temperature coefficient of resonant frequency (τ _f) is measured and the results demonstrate that the increment of Bi₂O₃ improves the thermal stability of the composites from −345.62 to −235.02 ppm/°C. For the dielectric properties, it is observed that Bi₂O₃ additions cause the formation of new phases, which present higher dielectric ϵ’ than SBN. Our numerical simulations show that the materials operate as DRAs and that SBN-Bi₂O₃ composites could be potential candidates for DRAs operating in the S band.

KEYWORDS:

• SrBi₂Nb₂O₉
• microwaves
• solid-state reaction
• dielectric resonator antennas

Acknowledgments

This work was partly sponsored by the Brazilian Research Agencies CNPq (Conselho Nacional de Desenvolvimento Científico e Tecnológico) (grant INCT NANO(BIO)SIMES), CAPES – Coordenação de Aperfeiçoamento de Pessoal de Ensino Superior (grant PNPD), FINEP - Financiadora de Estudos e Projetos (grants INFRAPESQ-11 and INFRAPESQ-12) and the U.S. Air Force Office of Scientific Research (AFOSR) (FA9550-16-1-0127).

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This work was partly sponsored by the Brazilian Research Agencies CNPq (Conselho Nacional de Desenvolvimento Científico e Tecnológico) (grant INCT NANO(BIO)SIMES), CAPES – Coordenação de Aperfeiçoamento de Pessoal de Ensino Superior (grant Project PNPD), FINEP – Financiadora de Estudos e Projetos and the Air Force Office of Scientific Research [grant number FA9550-16-1-0127].