Wide bandwidth measurement of complex permittivity of liquids using coplanar lines

A technique for measurement of complex permittivity of dielectric materials , using coplanar waveguide (CPW) cells is presented. A complete solution of the forward and inverse problems, based on a quasi-TEM propagation model, is given. Unlike other methods, our method allows solution of the inverse p roblem without the use of iterative or graphical techniques. The model acco unts for the various discontinuities along the line. Several advantages res ult from this approach. Measurement over a broad frequency range is possibl e, limited only by dispersive effects. It is suitable for solids not amenab le to machining for cavity measurements, and there need not be any contact.