Characterization of 3D-knitted Substrates

The paper deals with the relative permittivity measurement of the selected types of 3D-knitted fabrics by the two-line method combined with the matrix-pencil method and by the transmission/reflection method. The measured relative permittivity of the fabrics is in the range from 1.17 to 1.23. Further, the fabrics exhibit slight anisotropic behavior. The obtained results can be used for the design of the microwave devices where the 3D knitted fabrics play the role of the substrate.