Technique for Fast, Accurate Measurement of Complex Permittivity of EM Materials with Samples of Arbitrary Shape

This paper presents a novel technique for the measurement of complex permittivity of dielectric materials using samples of arbitrary shape and size. Traditional methods for the use of measuring dielectrics have historically required either large, flat samples of a material, or the material to be in powder form. This is limiting when it comes to modern applications, or in the study of archeological objects. Our approach, based on Resonant Cavity Perturbation theory (RCP), allows for the measurement of small, irregularly shaped samples by combining perturbations from three orthogonal modes in a cuboid cavity. We validate this technique by measuring various materials such as polymers and woods, the results of which demonstrate the effectiveness of the technique in providing reliable dielectric readings at microwave frequencies. This method may be particularly useful in the nondestructive characterization of archeological objects, or in the characterization of new materials.