The Ba16SnNb12O48 ceramics are prepared using a solid-state reaction method. The relationship between microstructure and dielectric properties are investigated. XRD and Rietveld refinements confirm that Ba16SnNb12O48 belongs to a hexagonal perovskite phase with R-3m space group. The change in permittivity is ascribed to the effect of the porosity. Packing fraction, grain size, and relative density are important factors affecting the dielectric loss. The temperature coefficient is influenced by temperature coefficient of dielectric constant and relative density. The infrared spectrum reveals that the dielectric response in microwave band is related to absorption of structural phonon oscillations in the far-infrared range. The Ba16SnNb12O48 ceramics sintered at 1440 degrees C exhibited the best microwave dielectric properties with epsilon(r) = 36.35, Q x f = 38,305 GHz, and tau(f) = 34 ppm/degrees C.
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