Signal attenuation in transmission lines

Abstract

Transmission lines are standard waveguiding structures used for data transmission in multi-point communications. Signal attenuation, signal integrity, and transmission loss associated with transmission lines are modeled and investigated in this paper. Performance of transmitting data in coaxial cables and in strip transmission lines are analyzed using an accurate and efficient method of moments (MoM) solution based on solving Maxwell's equations for the electromagnetic fields associated with waveguiding structures supporting data transmission in finite homogeneous and isotropic media. The analysis in this paper models attenuation losses, conductive losses, and dielectric losses for a coaxial cable and a printed circuit board (PCB). The models show that transmission loss is mainly dominated by conductive losses in metals for frequencies up to 25 GHz and by dielectric losses at much higher frequencies. Results show that high attenuation prevents data transmission at much higher frequencies unless the transmission line is designed using low-loss dielectric materials in the dielectric medium and high conductive material in the metals.