Mapping the foam-induced dielectric anisotropy for high-speed cables

Abstract

Foaming the expanded polyethylene (PE) is a prevailing way to lower the dielectric constants and dissipation factors of insulators in modern communication high-speed cables. The porosity and elongated cell shapes impose significant effects on the dielectric properties of PE. However, a theoretical study is lacking. This work proposes an effective way to predict the dielectric parameters of foamed PE. Unlike directly generating the extremely dense meshes for the randomly distributed pores, which is usually computationally intractable, we apply an electrodynamics homogenization method to obtain the equivalent anisotropic model for the complex foamed insulators. It is shown that the predicted values are amenable to the experimentally measured data.