| 摘要 |
<p>An active hybrid circuit for providing isolation between a signal receiving line and a signal transmitting line coupled to a two-wire telephone subset. The receiving line is coupled to a receiving amplifier having a differential output coupled to a pair of common terminals. The telephone subset is also connected to the two common terminals. The two common terminals are connected to the two inputs of a transmitting operational amplifier. The transmitting signal line is coupled to the output of the transmitting amplifier. A compensating network is connected between the input to the receiving amplifier and one of the inputs to the transmitting amplifier. The reflected signal produced at the output of the transmitting amplifier due to a received signal at the input to the receiving amplifier passing through the receiving amplifier and then through the transmitting amplifier is cancelled by an equal and opposite compensating signal occurring at the output of the transmitting amplifier by virtue of the received signal passing through the compensating network and the transmitting amplifier.</p> |
