Terahertz spectra of selected low-temperature cofired ceramics: A comparative study

Low-temperature cofired ceramics (LTCC) which exhibit low dielectric permittivity and low dielectric loss are promising platforms for emerging terahertz devices and systems including high-speed telecommunications. This study focuses on the analysis of the terahertz spectra of novel low dielectric permittivity LTCC materials, such as copper and zinc borates, zinc silicates, and lithium-containing dielectrics. Furthermore, their sintering conditions and THz characteristics were compared with the results presented for other materials in our previous works and those reported in literature, including selected microwave dielectric properties. The effect of sintering aids (AlF3CaB4O7 and CuBi2O4) on the dielectric properties of Li2WO4, LiBO2, and 75 wt.% CuB2O4–25 wt.% Cu3B2O6 composite was also investigated. XRD patterns and SEM images illustrate single phase composition and dense microstructure of the tested ceramics. We describe in details the time-domain spectroscopy setup used to measure the dielectric properties of the developed materials in the 0.1–3 THz range.