| 摘要 |
<p>1492045 Adaptive hybrid GENERAL ELECTRIC CO 28 Oct 1974 [29 Oct 1973] 46553/74 Heading H4R In an active hybrid circuit which is of the type described in Specification 1,491,885 in which an amplifier 20 feeding the transmit channel of a four wire circuit is fed both with the signal appearing across a fixed impedance means 17 connected to the two wire circuit and with a cancellation signal derived from the receive channel of the four wire circuit and in phase opposition to that part of the signal appearing across the fixed impedance means which derives from the receive channel of the four wire line, the cancellation signal is derived via a delay line impedance synthesizer network 25 which is controlled by correlation of the signal in the receive channel with the signal in the transmit channel of the four wire circuit. In an alternative embodiment, Fig. 2 (not shown) the impedance synthesizer network is connected in the connection between the output of amplifier 14 and the resistor 18a and a direct connection provided between amplifier 19 output and resistor 26. The impedance synthesizer is preferably a transversal equalizer network.</p> |
