Patent ID: 7466971
Filing Date: 2008-12-16
Classification: H04B

Abstract:
1. A communication system including a first transmission channel with a first end and a second end, the first end coupled to a first transformer and the second end coupled to a second transformer, a first end transceiver transmitting and receiving signals via the first transformer and a second end transceiver transmitting and receiving signals via the second transformer, a first signal being supplied at the first end, the first signal comprising a transmission signal component of the first transceiver and a receive signal component from the second transceiver, said communication system comprising: a replica transmitter that generates a replica of the transmission signal component of the first transceiver; a filter to filter the replica signal; and an active resistive summer receiving the first signal and the filtered replica signal as inputs to reduce the transmission signal component at an output of the active resistive summer, wherein said active resistive summer includes an operational amplifier having a first polarity input terminal, a second polarity input terminal, and an output terminal, said active resistive summer further comprising: a feedback element in communication with the output terminal and the second polarity input terminal; a first resistor in communication with the second polarity input terminal and the first signal; and a second resistor in communication with the second polarity input terminal and the filtered replica signal.