Microwave properties of Ba(Zn1/3Ta2/3)O3 dielectric resonators

The Effects of (Ba0.4Ca0.6)SiO3Nano Spheroidization Glass Additives on the Microstructure and Microwave Dielectric Properties of Ba(Zn1/3Ta2/3)O3Ceramics

“…It is believed that the increase in the quality factor (Q×f o ) value with an increase in sintering temperature is attributable to the ordering of ions as previously reported and that the decrease in quality factor by the addition of nano spheroidization glass powder is attributable to a secondary phase caused by the glass phase. The temperature coefficient of resonant frequency that is the important property of a dielectric resonator was in the range of 3-7.5 ppm/℃ for pure Ba(Zn 1/3 Ta 2/3 )O 3 depending on the sintering temperature and time, and this temperature coefficient value was shown to be similar to a previously reported value [2,3,4]. In the case of Ba(Zn 1/3 Ta 2/3 )O 3 ceramics containing glass powder, the temperature coefficient of resonant frequency decreased as an increase in the nano spheroidization glass powder content and was shown to range from -7 to 2 ppm/℃.…”

“…As can be seen therein, at a sintering temperature of 1500℃, the density increases as the nano spheroidization glass powder content and the sintering temperature increase, but at a nano spheroidization glass powder content of 1.0 wt%, the bulk density significantly decreases regardless of the sintering temperature. Generally, in the case of pure Ba(Zn 1/3 Ta 2/3 )O 3 , a sintering temperature of 1600℃ or a long sintering time is required to obtain a bulk density of 7.953 g/cm 3 or higher, but a bulk density of 7.53 g/cm 3 is shown even at a nano spheroidization glass powder content of 0.3 wt%, suggesting that the sintering temperature can be lowered by the addition of nano spheroidization glass powder. Fig.…”

“…The three important characteristics required for a microwave dielectric resonator are suitable dielectric constant for use, a high quality factor (Q×f o ), and a stability of the temperature coefficient of resonant frequency [1]. Typical compositions having a high quality factor among microwave dielectric properties include complex perovskite A 3 known to have a quality factor (Q×f o ), higher than 120,000 and a stable temperature coefficient of resonant frequency [2,3]. It is known that, to increase the quality factor of this composition, the ordering of the B-site (Zn and Ta) is required, and for this ordering, heat treatment at a temperature of 1600 ℃ or higher for a long time is required [4,5,6].…”

Study of structural, dielectric and electrical behavior of (1−x)Ba(Fe0.5Nb0.5)O3–xSrTiO3 ceramics

“…Unlike normal BaTiO 3 , the high permittivity materials are considered necessary for temperature stable multilayer capacitors, to show abnormally flat dielectric temperature curves [16]. Several researchers [17][18][19][20][21][22][23] had reported that the BFN-based electroceramics exhibit a very attractive dielectric and electric properties over a wide range of temperatures. Considerable debates still exit concerning the physical mechanisms governing their dielectric and electrical behaviours [19].…”

Effects of BaCu(B2O5) addition on phase transition, sintering temperature and microwave properties of Ba4LiTa3O12 ceramics

“…These materials are required to a high relative permittivity (ε r ) for miniaturization, a high quality factor (Q × f) for better selectivity and a near-zero temperature coefficient of resonant frequency ( f ) for stability, but in addition, low cost and minimization of components are two crucial requirements in commercial applications [1][2][3][4]. However, contemporary commercial resonator materials such as such as Ba(Mg 1/3 Ta 2/3 )O 3 , (Zr,Sn)TiO 4 , and CaTiO 3 -NdAlO 3 had the sintering temperatures higher than 1300 • C [4][5][6][7][8][9], which limits their applications in low-temperature cofired ceramic (LTCC) microwave devices. As a promising material for LTCC application, the sintering temperature of the ceramics should be lower than the melting point of silver (∼960 • C) [10,11].…”