Modeling and Verification of Automotive Multi-Gig Ethernet Communication up to 2.5 Gbps and the Corresponding EMC Analysis

Implementation of 5G mobile technology, fully autonomous driving, HD video transmission and much more are currently pursued by most of the automotive manufacturers worldwide. The bandwidth requirements for the realization of the mentioned objectives pose new challenges for the vehicle industry. Pulse amplitude modulation (PAM) is an effective approach for limiting the bandwidth. The increase in data rate and the use of higher modulation formats, e.g. PAM-5 to PAM-16, is associated with higher electrical interference sensitivity. The possible consequences are the reduction of signal-to-noise ratio (SNR), the increase of crosstalk, etc. Therefore, a tradeoff between bandwidth and the SNR is required. Pulse amplitude modulation with three signal levels (PAM-3) is implemented in 100BASE-T1 and 1000BASE-T1. There is no fixed definition of PAM level for 2.5 Gbps data transmission. As an example, for 2.5 Gbps with PAM-3 signaling, the required bandwidth is approx. 900 MHz - 1 GHz in the frequency domain. At such high-frequency ranges, the investigation of electromagnetic compatibility (EMC) of the Ethernet bus system plays an important role in designing the automotive Multi-Gig chips. The functionality of each physical component of the transmission system including the EMC issues should be modeled and verified. To the author's knowledge, this is the first time that SPICE model of the whole analog front end of automotive Multi-Gig Ethernet communication (up to 2.5 Gbps) is presented and verified by measurements.