Evaluation of the Dielectric Properties of CaMoO4‒TiO2 Composites for Microwave Applications Under Temperature Variation

• Published in: Journal of electronic materials Vol. 52; no. 4; pp. 2843 - 2851
• Main Authors: Nogueira, Francisco Enilton Alves, Abreu, Tallison Oliveira, Martins, Vitor Carvalho, Abreu, Roterdan Fernandes, do Carmo, Felipe Felix, do Nascimento, João Paulo Costa, Ghosh, Anupama, Sales, Antonio Jefferson Mangueira, da Silva, Marcelo Antonio Santos, da Silva, Ronaldo Santos, Sombra, Antonio Sérgio Bezerra
• Format: Journal Article
• Language: English
• Published: New York Springer US 01.04.2023; Springer Nature B.V
• Subjects: Calcium compounds; Characterization and Evaluation of Materials; Chemistry and Materials Science; Dielectric properties; Electronics and Microelectronics; Instrumentation; Laboratories; Materials Science; Molybdenum; Optical and Electronic Materials; Original Research Article; Physics; Radiation; Radio antennas; Resonators; Satellite communications; Solid State Physics; Thermal stability; Titanium dioxide; Dielectric resonator antenna (DRA); TiO; CMO; microwave; dielectric properties
• ISSN: 0361-5235; 1543-186X
• DOI: 10.1007/s11664-023-10248-6

This work presents experimental and numerical investigations of the microwave dielectric properties of the ceramic matrix CaMoO 4 (CMO) with the addition of 8, 12, and 20 wt% TiO 2 , obtained through the solid-state reaction method. X-ray diffraction and Rietveld’s refinement revealed no evidence of secondary phases, indicating no reaction between the CMO and TiO 2 phases. The dielectric properties presented an improvement with the addition of TiO 2 , with the CMO8 sample presenting ε r ′  = 12.8, tan δ  = 7.8 × 10 –4 , and τ f  =  − 6 ppm°C −1 , demonstrating that this material has thermal stability ( τ f  < 0). The ceramic was tested as a dielectric resonator antenna (DRA) and numerical simulation results showed that the materials have a realized gain of 4.40–4.92 dBi, a bandwidth of 741‒1079 MHz, and a radiation efficiency above 86%. The results indicate that CMO‒TiO 2 systems could be employed in devices operating in the S-band.