Nondestructive measurement of complex permittivity and permeability using multilayered coplanar waveguide structures

A method for simultaneous measurement of both complex permeability and permittivity is presented using a multilayered conductor-backed coplanar waveguide (MCBCPW) structure to evaluate the possibility of MCBCPW as a sensor for nondestructive electromagnetic measurement. Formulae and methods are developed to extract the electromagnetic parameters of material under test (MUT) placed on the topside of CPW. The measurement results for magnetic powder on MCBCPW sensor showed good agreement with those using coaxial sensors. The method allows both permittivity and permeability to be measured in a single-step measurement without modifying or reshaping the material, making this method particularly attractive for inhomogeneous materials such as biological materials.