Xiong Siyu, Zhu Xiaowei, Zhu Guobin, Chen Deqin, Cui Hongbo, Liu Laijun, Li Chunchun
Guangxi Universities Key Laboratory of Non-ferrous Metal Oxide Electronic Functional Materials and Devices, College of Material Science and Engineering, Guilin University of Technology, Guilin 541004, China.
Guangxi Key Laboratory of Embedded Technology and Intelligent System, College of Information Science and Engineering, Guilin University of Technology, Guilin 541004, China.
ACS Appl Mater Interfaces. 2025 Jan 8;17(1):1576-1585. doi: 10.1021/acsami.4c17300. Epub 2024 Dec 23.
A microwave dielectric ceramic based on lithium aluminum silicate (LiAlSiO) with ultralow permittivity was synthesized using the traditional solid-state reaction technique, and its dielectric characteristics at microwave frequencies are presented. The nominal LiAlSiO ceramic exhibited a relative permittivity of 3.95. To enhance the material properties, LiAlSiO- wt % BO microwave dielectric ceramics were fabricated by incorporating a low-melting-point sintering aid (BO), achieving a relative density exceeding 94%. The resultant ceramics exhibited a relative permittivity (ε) ranging from 3.95 to 4.42, a microwave quality factor ( × ) between 24,720 and 28,990 GHz, and a resonant frequency temperature coefficient (τ) varying from -45.9 to -20.6 ppm/°C. Additionally, the introduction of BO broadened the sintering temperature window and effectively lowered the optimal sintering temperature from 1400 to 1200 °C. Furthermore, LiAlSiO ceramics demonstrated a near-zero coefficient of thermal expansion (CTE) of 1.44 ppm/°C, which is advantageous for applications requiring high thermal stability. Based on LiAlSiO-2.0 wt % BO ceramics with ε = 4.42, × = 28,990 GHz, and τ = -20.6 ppm/°C, a microstrip patch antenna was designed and fabricated. Testing of the antenna revealed exceptional performance, including a center frequency of 4.98 GHz, a bandwidth of 280 MHz (-10 dB), and a total efficiency reaching up to 93.7%. These findings underscore the promising potential of this material in advanced microwave and wireless communication applications.
