Low-loss microwave dielectrics using SrTiO3-modified (Mg0.95Co0.05)2TiO4 ceramics

A novel low-loss microwave dielectric using (Ca0.8Sr0.2)TiO3-modified (Mg0.95Co0.05)2TiO4 ceramics

“…As x = 0.07, the 0.93(Mg 0.95 Co 0.05 ) 2 TiO 4 -0.07CaTiO 3 ceramics possessed a dielectric constant ε r of 17, a Q × f value of 90,000 GHz and a f value of −5 ppm/ • C [7]. Replacing CaTiO 3 by SrTiO 3 , the 0.93(Mg 0.95 Co 0.05 ) 2 TiO 4 -0.07SrTiO 3 composition showed an even higher Q × f of 102,200 GHz, associated with an ε r of 18.44 and a f value of 1.1 ppm/ • C [13]. Similar to CaTiO 3 and SrTiO 3 , (Ca 0.8 Sr 0.2 )TiO 3 was reported to have a ε r of 181, a Q × f of ∼8300 GHz (at 1.36 GHz) and a large positive f of ∼991 ppm/ • C [14] and has been shown as an effective f compensator for other materials [15].…”

The Enhanced Thermal Stability of (Mg0.95Ni0.05)2TiO4 Dielectric Ceramics Modified by a Multi-Phase Method

“…In (Mg 0.95 Zn 0.05 ) 2 TiO 4 -SrTiO 3 systems [21], the lattice parameters had slight influence and remained unchanged after the SrTiO 3 was added into (Mg 0.95 Zn 0.05 ) 2 TiO 4 , which confirms that the presence of a two-phase system could effectively promote densification in the (Mg 0.95 Zn 0.05 ) 2 TiO 4 matrix. In addition, CaTiO 3 -and SrTiO 3 -modified (Mg 0.95 Co 0.05 ) 2 TiO 4 ceramics [22,23] were presented using a multi-phase method for low-loss dielectric properties at microwave frequencies. Furthermore, thermal stability of dielectric ceramics is another important factor in practical applications.…”

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 .…”