Two novel garnet Sr3B2Ge3O12 (B = Yb, Ho) microwave dielectric ceramics with low permittivity and high Q

Developing low-loss and temperature-stable Ban(Zr,Nb)n−1O3n (n = 7, 8) microwave dielectric ceramics by investigating the relationship between the structure and properties

“…However, there is no correlation between the temperature coefficient and the sintering temperature, which is also observed in the Sr 3 B 2 Ge 3 O 12 (B = Yb, Ho), Mg 2 B 2 O 5 system. 29,30 The optimal MDPs of ε r ∼ 33.5, Q × f ∼ 56 500 GHz and τ f ∼ −17 ppm °C −1 for Ba 7 Zr 2 Nb 4 O 21 and ε r ∼ 32, Q × f ∼ 63 000 GHz and τ f ∼ −27 ppm °C −1 for the Ba 8 Zr 3 Nb 4 O 24 ceramic can be obtained. In future work, the positive temperature coefficient materials such as Ca 0.61 Nd 0.26 Ti 0.4 (Cr 0.5 Nb 0.5 ) 0.6 O 3 and CaTiO 3 ceramics can be considered to adjust the temperature coefficients of Ba 7 Zr 2 Nb 4 O 21 and Ba 8 Zr 3 Nb 4 O 24 ceramics.…”

“…10 To further confirm the Ba However, there is no correlation between the temperature coefficient and the sintering temperature, which is also observed in the Sr 3 B 2 Ge 3 O 12 (B = Yb, Ho), Mg 2 B 2 O 5 system. 29,30 The optimal MDPs of ε r ∼ 33. Based on this, the spherical pore model was used to further investigate the effect of pore on the permittivity.…”

Donor–acceptor modified ixiolite structural ceramics for millimeter-wave broadband metamaterial devices

“…Millimeter-wave technology with its extremely wide frequency band (B135 GHz, considering the atmospheric window), high resolution, low delay (less than 1 ms) and excellent transmission stability, has shown many advantages in current and future wireless communication systems, such as 5G (the 5th generation mobile communication technology), weapons guidance, radar systems and other military and civilian fields. [1][2][3][4][5][9][10][11][12] Correspondingly, to achieve high-performance of passive devices and reduce the power consumption problems from the increasing frequency, the dielectric performance of microwave dielectric ceramics (MWDCs) should be further optimised. In practical applications, the performance parameters of MWDCs should satisfy the following criteria: (a) a low dielectric loss (tan d), signifying a higher Q Â f value (Q E 1/tan d) to reduce signal damping; (b) a suitable dielectric constant (e r ) to match different device applications; (c) a near-zero temperature coefficient of the resonant frequency (t f ) to ensure thermal stability.…”

“…In practical applications, the performance parameters of MWDCs should satisfy the following criteria: (a) a low dielectric loss (tan d), signifying a higher Q Â f value (Q E 1/tan d) to reduce signal damping; (b) a suitable dielectric constant (e r ) to match different device applications; (c) a near-zero temperature coefficient of the resonant frequency (t f ) to ensure thermal stability. [5][6][7][8][9][10][11][12] Meanwhile, in the face of a more complex electromagnetic environment that is due to the complex system design according to the attenuation characteristics of millimeter-wave technology, high-performance passive devices should be investigated to provide an effective anti-electromagnetic interference (anti-EMI) function in many scenarios. These were important in preventing electromagnetic pollution (EMP) and promoting stealth technology.…”

“…In practical applications, the performance parameters of MWDCs should satisfy the following criteria: (a) a low dielectric loss (tan δ ), signifying a higher Q × f value ( Q ≈ 1/tan δ ) to reduce signal damping; (b) a suitable dielectric constant ( ε r ) to match different device applications; (c) a near-zero temperature coefficient of the resonant frequency ( τ f ) to ensure thermal stability. 5–12…”