Patent ID: 7154954

Claim:
A communication system utilizing two-wire transmission lines for transmitting a transmission signal represented by two AC components being opposite in phase appearance, comprising: a plurality of nodes respectively connected to said two-wire transmission lines, each of said nodes having therewithin: a low pass filter connected to said transmission lines, two terminating resistors respectively connected to said transmission lines via said low pass filter, and a reception circuit for receiving said transmission signal, said reception circuit including: an AC coupling circuit for extracting said AC components from said transmission signal on said transmission lines; a bias circuit for applying a bias voltage to the AC components extracted by said AC coupling circuit; and a clip circuit for clipping the level of each of the extracted AC components, wherein said clip circuit comprises: a resistor having one terminal connected to a reference potential; a bias current supply circuit for supplying a fixed bias current to said resistor; and a diode connected between the other terminal of said resistor and an output line of said AC coupling circuit.