New low‐ε_r, temperature stable Mg₃B₂O₆‐Ba₃(VO₄)₂ microwave composite ceramic for 5G application

Abstract

Novel lowε r , thermal and phase stable of (1-x)Mg 3 B 2 O 6 -xBa 3 (VO 4 ) 2 (x mol% =51, 53, 55, 57, 59) microwave composite ceramics were firstly fabricated and reported using the conventional solid-state reaction method. X-ray diffraction, scanning electron microscopy, energy dispersive X-ray, and Raman spectroscopy confirmed the coexistence of both phases without other phases. Near-zero temperature coefficient of resonant frequency (τ f ~ +1.2 ppm/°C) is obtained for the 0.43Mg 3 B 2 O 6 -0.57Ba 3 (VO 4 ) 2 composite ceramic, with permittivity (ε r ) of 8.8 and high-quality factor (Q×f) of 45 420 GHz, which is a promising candidate for 5G applications.

Microwave dielectric properties of (Na0.5Bi0.5)MoO4–BaMoO4 composite ceramics with ultralow sintering temperature

“…However, these materials face challenges, particularly the $${\tau }_f$$ values. Researchers have employed two primary strategies to address this; either by creating composite materials by mixing components with opposite $${\tau }_f$$ values, such as MgWO 4 –CaTiO 3 , Mg 3 B 2 O 6 –Ba 3 (VO 4 ) 2 , Ag 2 MoO 4 –Ag 0.5 Bi 0.5 MoO 4 , BaSi 2 O 5 –Ba 3 V 2 O 8 , and others 14–17 ; or by forming solid solutions 18–21 . An example of the latter approach is seen in studies on Pr 2 (Zr 1− x Ti x ) 3 (MoO 4 ) 9 solid solution ceramics, where ionic substitution has been used to significantly modify dielectric properties, aligning with the ongoing search of materials with tailored characteristics for advanced microwave applications 22 .…”

Sintering characteristics, phase transitions, and microwave dielectric properties of low-firing [(Na 0.5Bi 0.5) x Bi 1− x ](W x V 1− x )O 4 solid solution ceramics

“…The key characteristics required for ceramic materials to fabricate dielectric resonators are high relative permittivity (𝜀𝜀 𝑟𝑟 ) for miniaturization, excellent temperature-stable dielectric properties (near-zero TCF value) and high Q × f value > 5,000 GHz for optimal frequency selectivity. The importance of miniaturization has never been overemphasized in any application with the coming of the Fourth Industrial Revolution (4IR) [6][7][8]. Thus, there is a continuing driving force to develop ceramic materials with excellent dielectric properties and low sintering temperatures.…”

Low temperature sintering and dielectric properties of LaAlO3–BaSnO3-based microwave dielectrics

“…Microwave dielectric materials development with enhanced quality factor (Q × f ), mid-high dielectric constant value (ɛ r ) and having zero temperature coefficient of resonant frequency (Ƭ f ) for the use of microwave device substrates and dielectric resonators has been very quickly growing in the past decade [1][2][3][4][5][6]. Rear-earth aluminates, LaAlO 3 , have suitable permittivity values and quality factor values for the application of dielectric resonators, exhibiting a permittivity value of ∼23 and quality factor (Q × f ) value of 65,000 along with negative Ƭ f of ∼−44 ppm/ °C [7].…”