Near‐Zero Thermal Expansion Ba<sub>1−</sub><i><sub>x</sub></i>Sr<i><sub>x</sub></i>Zn<sub>2</sub>Si<sub>2</sub>O<sub>7</sub>‐Based Microwave Dielectric Ceramics for 3D Printed Dielectric Resonator Antenna with Integrative Lens
Zheng‐Yu Zou, Yihui Lou, Xiaoqiang Song, Hai Jiang, Kang Du, Changzhi Yin, Wenzhong Lü, Xiao‐Chuan Wang, Xiao‐Hong Wang, Ming Fu, Wen Lei
Abstract
Abstract High‐gain, low‐weight, wide bandwidth, and miniaturized lens antennas with stable properties against temperature are intensely required in extreme environments such as aerospace field. However, high‐performance microwave dielectric ceramics with near‐zero thermal expansion and frequency shift with temperature are very rare; moreover, the requirement of 3D printing processes also restricts their developments. Ba 0.4 Sr 0.6 Zn 2 Si 2 O 7 with negative coefficient of thermal expansion (CTE), which originates from the stretched [ZnO 4 ] tetrahedral chain to the twisted one along b ‐axis with temperature, and CaTiO 3 with positive temperature coefficient of resonant frequency (τ f ) can effectively adjust both CTE and τ f of Zn 1.8 SiO 3.8 to near‐zero value in 0.95(0.9Zn 1.8 SiO 3.8 –0.1Ba 0.4 Sr 0.6 Zn 2 Si 2 O 7 )–0.05CaTiO 3 ceramic. Then, a Ku‐band Luneburg lens integrative antenna fabricated by stereolithography 3D printing technology exhibits an average gain of 8.06 dBi at 10.45–11.39 GHz and 10.3 dBi at 12.27–13.45 GHz, which has potential applications in temperature‐stable satellite communication.