| 摘要 |
There is provided a coupling circuit for a full duplex modem having a transmitter (100) and a receiver (120). The coupling circuit includes a first transformer (250) having a primary winding and a secondary winding, where the primary winding is coupled to the transmitter, a second transformer (255) having a primary winding and a secondary winding, where the primary winding of the second transformer is coupled to a communications line, and a resistance (205) between a terminal of the primary winding of the first transformer and a terminal of the primary winding of the second transformer. The secondary windings of the first and second transformers are connected in series, with opposing phase, and coupled to the receiver to minimize a level of a signal from the transmitter from reaching the receiver. |
