Beyond 10Gbps Electrical Automotive Ethernet Channel Insertion Loss Characterization

Abstract

This research work focuses on electrical investigations and characterization of the Automotive Ethernet channel for 25Gbps (25GBASE-T1). This characterization is performed with the aid of insertion loss ($\mathrm{S}_{\mathrm{DD}12}/\mathrm{S}_{\mathrm{DD}21}$) mixed-mode scattering parameters (S-parameters) which describe the transmitted signal electrical behavior within the Ethernet channel considering it’s coupled transmission line characteristics. This paper commences with an introductory background of this research topic. This is then followed with an overview of the Automotive Ethernet channel and components. A succeeding section addresses the various channel electrical characteristic parameters. With the aid of implemented multi-gigabit Ethernet test boards, to emulate an ECU-ECU communication system setup, the fourth section investigates and discusses insertion loss test bench measurements and simulations on channel segments (PCB, link segment) and complete single 25Gbps (25GBASE-T1) Ethernet channel. The investigations in this study deploy Shielded Twisted Pair (STP) cables of varying length and cable topologies as a physical transmission medium. Last section addresses the key takeaways of this paper and recommendations on subsequent analysis.