Measurement of transfer characteristics of conducted disturbance from AC power supply port to Ethernet port considering transmission mode

Conducted disturbance from AC power supply reaches a communication cable (e.g. Ethernet cable) through a communication device (e.g. switching hub). Then it affects quality of the signal communication and/or the other communication devices because the conducted disturbance propagates along the communication cable. Transmission modes in a power supply cable or a Ethernet cable are defined in this paper. Two orthogonal transmission modes, normal mode and common mode, are defined in the power supply cable. And three modes, differential mode, primary common mode, and secondary common mode, are determined in the Ethernet cable. Additionally, a measurement system of transmission and mode conversion characteristics of the conducted disturbance considering transmission modes are constructed.