Simultaneous power injection in power over ethernet system

A method performed by a Power over Ethernet (PoE) circuit connected to a first pair of wires and a second pair of wires, the first pair of wires comprising a first conductor and a second conductor, the second pair of wires comprising a third conductor and a fourth conductor, the method comprising:

• operating a first portion comprising the steps of:
• transmitting first data signals, by a first transceiver having a first terminal and a second terminal, over the first wire pair;
• applying the first data signals across a primary winding of a first isolation transformer, the first isolation transformer also having a secondary winding, the secondary winding of the first isolation transformer having a first end coupled to the first conductor, and having a second end coupled to the second conductor, the secondary winding of the first isolation transformer having a first center tap;
• applying a voltage, corresponding to the first data signals, across the secondary winding of the first isolation transformer to the first wire pair;
• and
• applying a first DC voltage, from a DC power supply, to a first node of a first inductor and a second inductor connected in series across the first conductor and the second conductor;
• operating a second portion comprising the steps of:
• transmitting second data signals, by a second transceiver having a first terminal and a second terminal, over the second wire pair;
• applying the second data signals across a primary winding of a second isolation transformer, the second isolation transformer also having a secondary winding, the secondary winding of the second isolation transformer having a first end coupled to the third conductor, and having a second end coupled to the fourth conductor, the secondary winding of the second isolation transformer having a second center tap;
• applying a voltage, corresponding to the second data signals, across the secondary winding of the second isolation transformer to the second wire pair;
• and
• applying a second DC voltage, from the DC power supply, to a second node of a third inductor and a fourth inductor connected in series across the third conductor and the fourth conductor,
• such that DC power is supplied to the first wire pair via the first isolation transformer, the first inductor, and the second inductor, and power is returned from the second wire pair via the second isolation transformer, the third inductor, and the fourth inductor.