High‐Q and temperature‐stable microwave dielectrics in layer cofired Zn_1.01Nb₂O₆/TiO₂/Zn_1.01Nb₂O₆ ceramic architectures

Abstract

A multilayer cofired architecture was proposed and demonstrated to achieve high-Q and temperature-stable microwave dielectrics in a derived system, Zn 1.01 Nb 2 O 6 -TiO 2 . This approach could effectively allow the chemical reactions between Zn 1.01 Nb 2 O 6 and TiO 2 occur at a rather narrow area (~12 μm), the interfaces of heterogeneous layers, where the diffusion of Zn, Nb, and Ti could be observed. Such interfaces could act as the in situ "glues" to connect each layer well. The effects of stacking scheme and TiO 2 content on the microwave dielectric properties of layered architectures were investigated systematically. The resonant frequency, Q-factor, and electric field distribution were reported using the eigenmode solver of high-frequency structure simulator. Among the available layer architectures, the optimized microwave dielectric characteristic was observed in Zn 1.01 Nb 2 O 6 /TiO 2 /Zn 1.01 Nb 2 O 6 stacked with 0.058 mol TiO 2 (~1.84 vol%).The τ f can be effectively tuned to approximately +0.53 ppm/°C, and importantly, a high Q × f value~99 500 GHz together with ε r~2 6.8 was achieved. This design could be beneficial for opening up new ways to develop high-performance microwave dielectrics based on current material systems and therefore to meet with the high requirements for 5G wireless communication components and multilayer packing technology. K E Y W O R D Sdielectric materials/

Novel thermally stable, high quality factor Ba4(Pr0.4Sm0.6)28/3Ti18−yGa4y/3O54 microwave dielectric ceramics

“…In decades, due to the rapid development of wireless technology, the microwave components play an important role in the field of the fifth‐generation (5G) mobile communication, global positioning system, wireless fidelity, and so on . As the key materials, the microwave ceramics should possess high microwave dielectric constant ( ε r ), high quality factor (Qf) ( Q = ), and near‐zero TCF (temperature coefficient of resonant frequency) …”

The latest process and challenges of microwave dielectric ceramics based on pseudo phase diagrams

“…Adding secondary phase into ceramics to compensate for τ f value would introduce a large amount of second phase, which were ascribed to the large dielectric loss. Aiming to reduce the defects stemmed from the secondary phase, layercofired ceramic architectures were designed such as Zn 1.01 Nb 2 O 6 /TiO 2 /Zn 1.01 Nb 2 O 6 [3], MgTiO 3 /TiO 2 /MgTiO 3 [4], and Zn 3 Nb 2 O 8 /TiO 2 /Zn 3 Nb 2 O 8 [5]. High-Q value was remained and temperature-stable MWDCs were obtained for all the reported tri-layer co-fired ceramics.…”

“…Near-zero temperature coefficient of resonant frequency is also obtained by designing co-exited phase system with introduction of two ceramics with opposite τ f values, but the composite ceramics may lead to a poor Q×f value. More recently, the strategy of tri-layer structures of Zn 1.01 Nb 2 O 6 /TiO 2 /Zn 1.01 Nb 2 O 6 [3], MgTiO 3 /TiO 2 /MgTiO 3 [4], and Zn 3 Nb 2 O 8 /TiO 2 / Zn 3 Nb 2 O 8 [5] were verified as a method to obtain the temperature-stable ceramics with low dielectric loss.…”

Vibrational spectroscopy and microwave dielectric properties of AY2Si3O10 (A=Sr, Ba) ceramics for 5G applications

“…[1][2][3] According to the world wireless society, the assigned working frequency bands for 5G are ultimately 24 -30 GHz or 60 GHz -70 GHz with delay time of signal transmission < 1ms. 4 Unlike 2G/3G/4G mobile communications, the carrier frequency of 5G is extended to millimeter wave band rather than microwave band, which has enormous implications for the development of microwave dielectrics. Since the delay time is proportional to the square root of dielectric permittivity ( r), the radio signal propagation velocity can be increased by using dielectrics with low r. 5 Furthermore, high quality factor (Qf) is required to decrease energy loss with near zero temperature coefficients of resonant frequency ( f) paramount to maintain operating stability.…”