A power over Ethernet (PoE) interface for 10GBase-T Ethernet includes at least one communication channel Ethernet interface including an autotransformer having a center tap for coupling direct current (DC) power. A combination of the geometry of the toroid core of the autotransformer and in some embodiments of a common mode choke, as well as the wire twisting, the wire distribution and the wire routing allow maximizing bandwidth up to or greater than 500 MHz for 10GBase-T performance by increasing the coupling and reducing capacitance across the wires, and results in return and insertion losses and OCL that meet anticipated standards.