A New Microwave Method of Measuring Complex Dielectric Constant of High-Permittivity Thin Films

A new method of measurement of complex dielectric constant of thin films of high-permittivity materials at microwave range of frequencies is suggested. The experimental sample is in the form of a planar condensor supported by means of (λ/2)g substrate inside the waveguide. ϵ of the sample is found by noting the resonant frequency, and tgδ is obtained from the reflection coefficient of the resonance-tuned system. A working equation for the capacitor is derived with help of conformal mapping. The applicability of the method has been verified with an experimental sample of BaTiO3.