Abstract: Yarn containing metal fiber is a mixture of metal fiber, conventional fiber and air, and the research on its permittivity is complex. In this paper, the PET plate, copper plate and air are connected in series in different ways to simulate the ideal structure of metal fiber-contained yarns and deduce the calculation formula for the permittivity in different series connections. At the same time, the permittivity in different series connections is tested by the dielectric spectrometer, the test results are in good conformity with the calculation results. Under the experimental conditions, the permittivity of the composite increases with the increase of the metal content, and decreases with the increase of PET content and air content. It can provide guidance for the theoretical study on the permittivity of yarn containing metal fiber.

Key words: metal fiber yarn; permittivity; series connection; influential factors