The low dielectric constant(ε_(r)<15)is the key to improving the signal transmission speed of microwave communication devices.However,the resonant frequency temperature coefficient(τf)of most low-ε_(r) microwave...The low dielectric constant(ε_(r)<15)is the key to improving the signal transmission speed of microwave communication devices.However,the resonant frequency temperature coefficient(τf)of most low-ε_(r) microwave dielectric ceramics is usually negative.Aiming to modify the large negativeτf of scheelite CaWO4 and explore the underlying mechanism between the structure and microwave dielectric properties,a series of Ca_(1-x)(Li_(1/2)Eu_(1/2))_(x)WO_(4)(x=0.1−1.0)(CLEWOx)ceramics were prepared at low sintering temperatures(750−875℃).Theε_(r) increased from 10.46 to 18.55,and the Q×f decreased from 39,032 GHz-7425 GHz,mainly due to the enhanced rattling effect of Li+.Theτf rapidly increased from negative(−19.91×10^(−6)℃^(−1))to abnormally positive(+162.15×10^(−6)℃^(−1)),influenced by the reduced temperature coefficient of ion polarizability(ταm)caused by the rattling Li+cation.The CLEWO0.15 sample has good comprehensive performance(ε_(r)=12.28,Q×f=28,027 GHz,andτf=−0.5×10^(−6)℃^(−1))and compatibility with the Ag electrode,showing the potential of LTCC applications.Additionally,a dielectric resonator antenna based on CLEWO0.15 ceramic was designed with a bandwidth of 254 MHz at 4.504−4.758 GHz and a gain of 4.87 dBi at 4.62 GHz,indicating that CLEWO0.15 may be a potential candidate for dielectric resonator antennas.展开更多
基金supported by Project of Scientific Research,Technical Exploitation Program of the Guangxi Zhuang Autonomous Region(No.AD24010021)Natural Science Foundation of Guangxi Zhuang Autonomous Region(No.2024GXNSFFA010013)the National Natural Science Foundation of China(Nos.52362017 and 52462016).
文摘The low dielectric constant(ε_(r)<15)is the key to improving the signal transmission speed of microwave communication devices.However,the resonant frequency temperature coefficient(τf)of most low-ε_(r) microwave dielectric ceramics is usually negative.Aiming to modify the large negativeτf of scheelite CaWO4 and explore the underlying mechanism between the structure and microwave dielectric properties,a series of Ca_(1-x)(Li_(1/2)Eu_(1/2))_(x)WO_(4)(x=0.1−1.0)(CLEWOx)ceramics were prepared at low sintering temperatures(750−875℃).Theε_(r) increased from 10.46 to 18.55,and the Q×f decreased from 39,032 GHz-7425 GHz,mainly due to the enhanced rattling effect of Li+.Theτf rapidly increased from negative(−19.91×10^(−6)℃^(−1))to abnormally positive(+162.15×10^(−6)℃^(−1)),influenced by the reduced temperature coefficient of ion polarizability(ταm)caused by the rattling Li+cation.The CLEWO0.15 sample has good comprehensive performance(ε_(r)=12.28,Q×f=28,027 GHz,andτf=−0.5×10^(−6)℃^(−1))and compatibility with the Ag electrode,showing the potential of LTCC applications.Additionally,a dielectric resonator antenna based on CLEWO0.15 ceramic was designed with a bandwidth of 254 MHz at 4.504−4.758 GHz and a gain of 4.87 dBi at 4.62 GHz,indicating that CLEWO0.15 may be a potential candidate for dielectric resonator antennas.
