System-Level Response of Ethernet Linkage to Bulk Current Injection into Cables

Wireline data linkage over 802.3ab, 1000BASE-T Ethernet is tested for electromagnetic susceptibility (EMS) under radio frequency (RF) disturbance from 10 MHz to 1 GHz with bulk current injection (BCI) to category 5 cables, by referring to IEC 61000-4-6. System-level evaluation uses a data quality analyzer in a loop through layer-2 switch equipment. The highest data rate nominally at 1 Gb/s is degraded down to almost at the null, with the RF disturbance for the frequency range below 80 MHz, while being less susceptible for the frequency higher than 200 MHz, generally evaluated among three different L2 switch products. The observations also reveal that the RF power is converted into voltage variations on wires of a twisted pair, which would be a primal cause of the degradation.