ACTIVE TERMINATING DEVICE WITH OPTIONAL LINE-RECEIVING AND LINE-DRIVING CAPABILITIES

摘要

An active terminating device (30) for an electrical transmission line withoptional line-receiving and line-driving capabilities. The basic device is atwo-terminal unit, denoted as a Signal Canceling Unit (SCU), which senses thesignal available at its terminals (34a, 34b), and applies negative feedback inorder to cancel and absorb the signal. When applied to the end of atransmission line (15a, 15b) as part of wired communication network, the SCUfunctions as a terminator. When connected in the middle of such wiredtransmission line, the SCU splits the transmission line into two separate andisolated segments. In such a configuration, the SCU can be used to isolate aportion of a network from signal degradation due to noise or bridge-tap.Furthermore, the two isolated segments may each employ independentcommunications, such that no interference exists between the segments. Inanother embodiment, line receiver functionality is integrated into the SCU,designated as a Signal Canceling and Receiving Unit (SCRU) (90). The SCRU canperform all the SCU functions, and also serves as a line receiver in thecommunication network. In yet another embodiment, line driver functionality isintegrated into the SCRU, designated as a Signal Canceling, Receiving andTransmitting Unit (SCRTU) (120). The SCRTU can perform all the SCRU functions,and also serves as a line driver in the communication network. Upon connectingmultiple SCRTU's to a continuous transmission line, terminated independentpoint-to-point communication segments are formed.