Broadband permittivity measurements of thin-film ferroelectrics to 40 GHz

We demonstrate a novel experimental technique to measure the complex permittivity of dielectric thin films over the frequency range from 100 Hz to 40 GHz. We apply this technique to determine the broadband permittivity for ferroelectric thin films such as PbTiO3 at room temperature. We discuss the value of such frequency-dependent measurements for determining the dielectric response of ferroelectric thin films at finite frequencies.