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