Abstract: Coupling circuit for coupling a power line communication device to a power line network, including a first network port coupled between a network phase line and a first network line, a second network port coupled between a network neutral line and a second network line, a third network port coupled between a network ground line and a third network line, a first differential modem port including a first terminal and a second terminal, a second differential modem port including a third terminal and a fourth terminal, a first transformer including a first network side winding and a first modem side winding, a second transformer including a second network side winding and a second modem side winding, the transformers including respective terminals, a center tap extending from the midpoint of the first network side winding to a terminal of the second network side winding and a plurality of capacitors.