High Performance Low Temperature Sintered LZT Dielectric Ceramics Materials And Its Application

In recent years,with the rapid development of electronic communication and radio frequency products,terminal communication equipment is rapidly developing in terms of miniaturization,integration,and high reliability,which poses a huge challenge to microwave dielectric ceramic materials.Among them,with low sintering temperature,high-performance LZT microwave dielectric ceramic materials play an important role in low temperature co-fired ceramics.In this paper,the more popular titanate microwave dielectric ceramic materials have been studied in recent years.Firstly,for Li₂ZnTi₃O₈ microwave dielectric ceramic materials,it is studied to incorporate various types of glass as sintering aids,and simultaneously reduce the temperature at four temperature points around 900°C,and analyze density and phase of each sample after sintering.Composition and dielectric properties include the most important parameter Q×f value and the compatibility of Li₂ZnTi₃O₈ with Ag.It can be found that the sintering temperature of the material is lowered by introducing low-melting glass LBSCA.When the amount of doped glass is x=1.5,the best performance when calcined at 900°C is?_r=23,Q×f=40,321 GHz,?_f=-13.75 ppm/°C.In order to prepare good temperature stability and better performance ceramics,Li₂TiO₃ is mixed with Li₂ZnTi₃O₈ microwave dielectric ceramics,and compensated by positive and negative temperature coefficients,then LMZBS and LBSCA glass are added,respectively at 875°C,900°C,925°C.Sintering was carried out at 950°C.Since the addition of Li₂TiO₃ will inevitably lead to a decrease in the low-temperature sintering property of the titanate,a trace amount of the glass liquid phase is added to the titanate,and the results are obtained by comparative test analysis.0.73Li₂ZnTi₃O₈-0.27Li₂TiO₃+x wt%LBSCA?x=0¹.5?,when x=0.75,the ceramics exhibited better microwave performance when kept at 900°C for 3 h:?_r=23.907,Q×f=63,050 GHz,?_f=1.2 ppm/°C.When the titanate ceramic system was cooled by LMZBS,its microscopic appearance and dielectric loss were studied.It can be roughly concluded that the Q×f value of the ceramic material sintered at 900°C is up to 30,000GHz when the doping amount x=0.75.In addition,in order to improve the microwave dielectric properties of titanate,by conducting a small amount of Co instead of Zn ions on Li₂ZnTi₃O₈ and then doping the glass,of course,firstly fix the glass doping amount to Li₂(Zn_1-xCo_x)Ti₃O₈+1 wt%LBSCA glass.The experimental sintering was carried out at x=0,0.03,0.05,and 0.07,respectively.At the same time,the comparative analysis of the ceramic material Li₂(Zn_1-xCo_x)Ti₃O₈+1 wt%LMZBS showed that Li₂(Zn_0.97Co_0.03)Ti₃O₈+1 wt%LBSCA the Q×f value of the ceramic material at 900°C reached a maximum of 81,300 GHz.Finally,through the previous experience of cobalt ion substitution and the experimental scheme of adding Li₂TiO₃ composite doping to adjust the temperature coefficient,try to adjust the cobalt ion substitution and the temperature coefficient simultaneously,and select the constant ratio with better effect.The sintering aid LBSCA glass is a ceramic material of 0.6Li₂(Zn_1-xCo_x)Ti₃O₈+0.4 Li₂TiO₃+1.5 wt%LBSCA?x=0,0.03,0.05,0.07?at 875°C,900°C,925°C,respectively.Sintering,the ceramic material was finally found to exhibit excellent microwave dielectric properties at x=0.03 and sintered at 900°C for 3 h:?_r=22.4,Q×f=85,200 GHz,?_f=2.6 ppm/°C.Based on the self-developed titanate ceramic material 0.6Li₂(Zn_1-xCo_x)Ti₃O₈+0.4Li₂TiO₃+1.5 wt%LBSCA with good microwave performance,a small type of coaxial back-fed rectangular microstrip patch antenna was explored.The HFSS software performs 3D electromagnetic simulation.The performance index is:the center frequency f is 2.36 GHz,BW>15 MHz,the in-band return loss S₁₁>20 dB,and the maximum gain is G=2.36 dB,which has practical production value,and in principle,in principle meets the patch antenna index under the established material.