Relative permittivity measurement of thick-film dielectrics at microwave frequencies

A novel extension of the resonant cavity technique used to measure relative permittivity at microwave frequencies is presented. The new technique is aimed particularly at the measurement of very thin dielectric layers and has been used to measure the permittivity of a thin dielectric layer printed onto a thick substrate whose permittivity is known. Successful experimental data has been obtained for 100 μm thick dielectrics at X-band