The present invention provides ceramic dielectrics for use in electronic components and the subsequent methods of forming them. In the ceramic dielectrics, CaTiO.sub.3 or MgTiO.sub.3 and/or SrTiO.sub.3 are incorporated in a Ba(Zn.sub.1/3, Ta.sub.2/3)O.sub.3 -base or a Ba(Mg.sub.1/3, Ta.sub.2/3)O.sub.3 -base ceramics. In addition, SiO.sub.2 and/or B.sub.2 O.sub.3, MnO and/or ZnO may be added as additives. The ceramic dielectrics have large unloaded Q-value and high relative dielectric constant, and a small temperature coefficient of resonant frequency. Each of the ceramic dielectrics can be easily formed at a lower sintering temperature (1200.degree..about.1650.degree. C.) than usual.
Dielectric materials are disclosed that are based on BaO--ZnO--Ta.sub.2 O.sub.5 represented by the formula Ba(Zn.sub.1/3 Ta.sub.2/3)O.sub.3. Ba has been partly replaced by K and either Zn or Ta has been replaced by at least one element selected from Mg, Zr, Ga, Ni, Nb, Sn. The dielectric materials have a relatively high permittivity, a small absolute value of the temperature coefficient of resonance frequency, and a high unloaded quality factor. A method for producing the dielectric materials is also disclosed which includes mixing given amounts of starting materials, such as, for example, BaCO.sub.3, ZnO, Ta.sub.2 O.sub.5, K.sub.2 CO.sub.3, MgCO.sub.3, SnO.sub.2 or ZrO.sub.2, compacting the mixture to produce a compact, sintering the compact in an oxidizing atmosphere such as, for example, air, at 1,400 and 1,600.degree. C., more preferably at 1,550 to 1,600.degree. C. for 2 hours, and then heating the sintered compact at a temperature lower than the sintering temperature by from 50 to 250.degree. C., e.g., by 100.degree. C., for at least 12 hours, preferably for 24 hours. A dielectric resonator comprising the dielectric material of the present invention is also disclosed.
An embodiment of the present invention provides an electronically tunable dielectric material, comprising at least one electronically tunable dielectric phase and at least one compound of low loss complex perovskites. The at least one electronically tunable dielectric phase may be selected from the group consisting of barium strontium titanate, barium titanate, strontium titanate, barium calcium titanate, barium calcium zirconium titanate, lead titanate, lead zirconium titanate, lead lanthanum zirconium titanate, lead niobate, lead tantalate, potassium strontium niobate, sodium barium niobate/potassium phosphate, potassium niobate, lithium niobate, lithium tantalate, lanthanum tantalate, barium calcium zirconium titanate, sodium nitrate, and combinations thereof. Further, the barium strontium titanate may of the formula BaxSr1-xTiO3, where x is from about 0 to about 1, or more specifically, but not limited in this respect, may also be of the formula BaxSr1-xTiO3, where x may be from about 0.15 to about 0.65 or from about 0.25 to about 0.60.
