Measurements of the complex refractive index properties of the liquid crystal materials by using the W-band waveguide test cell

Refractive index and loss properties are measured by using W-band rectangular waveguide test cell. Measurement of material properties in the ultrahigh frequency region becomes extremely difficult. We have proposed a novel measurements method utilizing the reflection type test cell fabricated with rectangular waveguide. Fundamental transmission mode in the waveguide is very simple and anisotropy of the LC materials can easily be determined by changing the direction of the magnetic field applied for the LC molecular orientation, in this work, we use a Teflon window for sealing the liquid like LC materials to reduce the reflection of the MMW signal. Complex refractive indices of the LC materials can successfully be determined up to 110GHz without any complex data analysis.