Patent ID: 8232666

Claim:
An apparatus comprising: a line driver coupled to receive an output from a transmit circuit as an input to the line driver; a first signal conditioner coupled to receive an output from the line driver as an input to the first signal conditioner; a first transformer coupled to receive an output from the first signal conditioner on a first winding side of the first transformer; a second signal conditioner coupled to a second winding side of the first transformer; a second transformer having a first winding side of the second transformer coupled to the second signal conditioner; a third signal conditioner coupled between a second winding side of the second transformer and an AC power line; a third transformer having a first winding side of the third transformer coupled to a transmit path; and a fourth signal conditioner coupled to receive an input from a second winding side of the third transformer and to couple an output from the fourth signal conditioner to a receive circuit, wherein the transmit path for a transmit signal from the transmit circuit to the AC power line is via the line driver, first signal conditioner, first transformer, second signal conditioner, second transformer and the third signal conditioner and wherein a receive path for a receive signal from the AC power line to the receive circuit is via a portion of the transmit path, the third transformer and the fourth signal conditional, in which the transformers provide coupling and the signal conditioners provide signal conditioning.