Abstract: A surge protector for highspeed data networks is provided wherein a circuit board having a ground plane formed on one side of the circuit board, has respective pairs of conductive traces forming impedancematched transmission lines on the other side of the circuit board. Surge protection devices are connected in series with the conductors and with the ground plane. A compensating reactance may be provided along the transmission lines to correct for parasitic capacitance introduced by the threshold voltage conductor devices. Shielded and isolated connectors may be provided at either end of the circuit board to minimize insertion loss and provide isolation between respective transmission lines.