Complex permittivity measurement of aluminum nitride by the cut-off circular waveguide method from 40GHz to 100GHz

The usefulness of the complex permittivity measurement for high dielectric constant material with ε
_r
≈ 8~10 by the cut-off circular waveguide method in W band is investigated. The frequency dependence of the complex permittivity for aluminum nitride plates is measured form 40GHz to 100GHz by using 50GHz, 80GHz and 100GHz cavity resonators, and compared with the calculated results of Debye-type dielectric dispersion due to dipolar relaxation. The measured results show the validity of this method for high dielectric constant material in W band.