The Investigation And Application For Microwave Dielectric Material Of Mgo-TiO₂

Microwave dielectric materials play an important role in modern communicationsystem. We investigated the relationship between the microstructure and dielectricproperties for MgTiO₃and Mg_1.8Ti_1.1O₄systems in this paper. The phase constitute,crystal structures and divalent ion substitution on structures and bond iconicity wereconsidered for modification of dielectric properties. Additions with positivetemperature coefficient of resonance frequency were employed to achieve themicrowave dielectric substrate and resonator that have near-zero temperaturecoefficient of resonance frequency. In addition, we design and simulate the microstripfilter by ADS software.1. MgTiO₃and （Mg1-xMx）TiO₃（M=Ni, Zn, Co and Mn） ceramics with singlephase have been prepared by conventional solid state method and the crystal structurewas also analyzed by Rietveld refine method The effects of divalent ion substitutionon the structure, bond iconicity and microwave dielectric properties were discussedsystematically. In order to study the correlation between dielectric properties withdifferent addition and microstructure, the concept of densification, polarizabilities,packing fraction and bond valence were investigated and discussed deeply. And wechoose the appropriate addition to improve the temperature coefficient of resonancefrequency and prepare the microwave dielectric substrate.2. We finally choose ZnO to improve the properties by investigated the additivesof microwave dielectrics.（Mg1-xZnx）_1.8Ti_1.1O₄（x=0.00-0.10） ceramics with differentZnO addition concentration were investigated and the relationships between crystalstructures and microwave dielectric properties were analyzed.Other more, weinvestigated the mechanism of lowing temperature and then prepare microwavedielectric resonator that have near-zero temperature coefficient of resonancefrequency by add compensation materials.3. Design and simulate microstrip filter by using software of ADS. Furthermore,the filter was manufactured using substrate of FR4and its properties were measuredby network analyzer.