Dielectric properties and mixture behavior of Mg4Nb2O9–SrTiO3 ceramic system at microwave frequency

Phase composition and microwave dielectric properties of SrTiO3 modified Mg2Al4Si5O18 cordierite ceramics

“…The one was that appropriate SrTiO 3 addition improved the (1 À x)MAS-xST ceramics densities, and reduced the porosity of cordierite solid solution ceramics. However, due to the poor quality factor of the SrAl 2 Si 2 O 8 (Qf: $ 14,600 GHz) and SrTiO 3 (Qf: $ 4200 GHz) [31,32], the Qf values of (1 À x)MAS-xST (0.15 6 x 6 0.35) ceramics appeared to decrease. At the same time, it was also well known that the dielectric losses were always accompanied with strong spontaneous polarization, which was caused by large displacements and distortions of atoms or other polyhedrons.…”

Low‐temperature‐sintered MgO‐based microwave dielectric ceramics with ultralow loss and high thermal conductivity

“…It has great microwave dielectric properties of relative permittivity ε r = 9.85 and dielectric loss tan δ = 0.4 × 10 −5 at 8 GHz 14 . Many microwave dielectric ceramics have been fabricated from MgO as well, including Mg 2 SiO 4 and Mg 4 Nb 2 O 9 15,16 . High thermal conductivity is another significant advantage of MgO ceramic.…”

Microwave Dielectric Properties of (1 − x)(Mg0.95Ni0.05)TiO3–x(Ca0.8Sr0.2)TiO3 Ceramic System With Near‐Zero Temperature Coefficient

“…In particular, size reduction is mainly a result from the use of high dielectric constant material as the wavelength (λ) in dielectrics is inversely proportional to according to the relation where λ o is the wavelength in vacuum. However, as the frequency of interest is extended from ISM (industrial, scientific, and medical) bands to millimeter wave range, materials with high dielectric constant tend to become a less of interest . Consequently, high quality factor together with low dielectric constant would play a more prominent role instead, as high quality factor can significantly reduce the dielectric loss, and low dielectric constant allows a fast time for electronic signal transition at ultra high frequencies.…”

“…Zero τ f value (temperature coefficient of resonant frequency) is also one of the major requirements for dielectric materials to allow a frequency‐stable passive component. The most convenient and promising way to achieve a zero τ f value is to combine two compounds having negative and positive τ f values to form a solid solution or mixed phases . However, high dielectric constant materials, in general, exhibit high dielectric loss (low Q × f value) and large positive τ f value, whereas low loss ceramics are usually accompanied by low ε r value and negative τ f value .…”