Study on microwave attenuation performance of MgO-Mg2SiO4 lossy ceramics

MgO-Mg₂SiO₄ composites were manufactured by hot pressing with the objective of producing electromagnetically lossy materials in the 8-12 GHz region. The effect of MgO content on microwave attenuation performance was studied with network analyzer. The result shows that the resonant frequencies become lower while increasing the content of MgO. The characteristics of microwave attenuation spectrum of the composites were analyzed by resonant-cavity theory and the result indicates that the resonant frequencies of the composites depend on their relative permittivities which can be measured by reflection-transition method. The permittivities measured agree well with the relative values calculated by resonant-cavity theory. The mechanisms of microwave attenuation were discussed.