PURPOSE: To cancel crosstalk affected onto other pattern wiring due to a signal of the relevant pattern wiring effectively by providing a guard pattern arranged in parallel corresponding to each pattern wiring and driving the guard pattern with a current of opposite polarity to that of the signal of the pattern wiring and proportional to the level of the signal.

CONSTITUTION: A signal of opposite polarity through an inverting amplifier 52 and a current output Ix with a level proportional to a transmission signal through current amplifiers 421, 422 are fed respectively to guard patterns 232, 233 in the case of signal transmission from a driver 12 to a receiver 32. Thus, an induced voltage from a pattern wire 22 and an induced voltage of opposite polarity from guard patterns 232, 233 driven by an inverting amplifier and a current amplifier are generated in the pattern wire 21. That is, the induced voltage of the transmission signal through the pattern wire into an adjacent pattern wire is cancelled by the drive current of the guard pattern. Thus, crosstalk is reduced while decreasing the circuit integration of the pattern wires and eliminating the need for a multilayer board.