A titanium-dioxide based ceramic composite dispersed with conducting inclusions as an EMI shielding material

A class of composite materials constituted by conducting inclusions dispersed in a host ceramic medium (such as TiO/sub 2/) is described. This test composite is studied as a potential EMI (electromagnetic interference) shielding material. A mixture formula for predicting the effective electrical conductivity of the test composite in terms of the volume fraction and geometric aspect of the conducting inclusions and the permittivity of the host medium is indicated for calculating the shielding effectiveness of the material. Theoretical and experimental results are furnished and discussed. Depending on the conducting particulate loading, the shielding effectiveness of the composite(s) falls in the range of 5-20 dB over the frequency range of 500 MHz to 1 GHz.<
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