摘要
Dense microwave dielectric ceramics of Sr_(1-x)Ca_(x)Tm_(2)O_(4)(x=0.025-0.300)were fabricated via the conventional solid-state reaction method.Systematical investigations on the impact of Ca^(2+)on their microstructures,sintering behaviors,and microwave dielectric properties were detailly conducted.The combined XRD data and subsequent refinement demonstrated that all samples exhibited structural conformity with SrTm_(2)O_(4) and belonged to Pnam space group.Calculations were executed to illustrate the evolution of performance-related chemical bonding parameters associated with Ca^(2+)on the basis of the PVL theory.High density,lattice energy and narrow full width at half maximum of Raman modes contribute to a performance boost of around 14%.Excellent dielectric properties of Sr_(0.95)Ca_(0.05)Tm_(2)O_(4),including relative permittivity of 15.97,quality factor of 47,142 GHz,and temperature coefficient of resonant frequency of−24.65×10^(−6)℃^(−1).Furthermore,Sr_(0.95)Ca_(0.05)Tm_(2)O_(4) ceramics were designed as rectangular dielectric resonator antennas with 388 MHz bandwidth at the center frequency of 6.525 GHz,along with high simulated radiation efficiency(≥90%)and realized gain(5.80-6.47 dBi),which suggests their considerable potential in 5G communication applications.
基金
supported by National Natural Science Foundation of China(No.61761015)
Guangxi Natural Science Foundation(No.2024GXNSFDA010060)
Guilin Science Research and Technology Development Plan Project(20230120-8).
