Design of a Waveguide Test Cell for Q Band Liquid Permittivity Measurements

We present a novel design of a rectangular waveguide test cell for measurements of complex liquid permittivity in a 33-50 GHz microwave band. The cell allows for multistate 2-port measurements with a vector network analyzer and is compatible with the standard WR-22 waveguide flange. Using electromagnetic simulations, we investigate the permittivity error introduced by the liquid inlet depending on its position, inner diameter and length.