Relative permittivity extraction of Textile materials based on ridge gap waveguide technology

The Textile materials are widely used recently in microwave applications. The wearable antennas and the medical applications generate high potential to explore the electrical characteristics of the Textile materials. The mechanical properties of such materials are well known but the challenge is to determine the electric characteristics in an accurate way specially the relative permittivity. There are many traditional methods to identify the relative permittivity of an unknown material e.g. Coaxial probe method, the waveguide method, the free space method, and the cavity method. On the other hand, the Textile materials have relatively small standard thickness. This put some limitations on the used measurement technique. The objective is to select a suitable measurement technique for wide band operation and a small thickness for the sample under test.