Abstract: An active hybrid circuit for a full duplex channel generates a duplicated voltage at the current output stage to reduce the energy of the transmitter transmitted to the receiver. The active hybrid circuit cancels the energy of the transmitter transmitted to the receiver when it is operated in a full duplex channel with high-speed transmission. The active hybrid circuit for full a duplex channel comprises a transmit digital-to-analog converter for generating an analog transmit signal, a receive analog-to-digital converter for receiving an analog receive signal, a duplicated voltage digital-to-analog converter for generating a corresponding duplicated voltage according to the analog transmit signal of the transmit digital-to-analog converter, and a plurality of signal combiners for subtracting the duplicated voltage from the analog transmit signal to cancel the influence of analog transmit signal to the analog receive signal.