The dielectric constant measurement using a TE01 mode in W-band

The dielectric constant varies with frequency so that the known dielectric constant at low-frequency is no longer valid at high-frequency regions. When the frequency increases, experimental imperfection such as air gap between a sample and a resonator cannot be ignored anymore in the dielectric constant measurement by means of the resonator method. In contrast to the existing resonator method using a fundamental TE10 mode in a rectangular waveguide, we propose to use a TE01mode in a circular waveguide which is less affected by the air gap between the surface of the waveguide and the dielectric material