摘要 |
An apparatus is provided for high frequency multiplexed electrical line communication for cable TV, telephone, internet, security and other control applications over the mid and low voltage power lines and directly through the transformers. The apparatus includes a transmitter, a receiver, a modem (14), a multiplexer and multiple couplers (28) at each of two or more locations along an electrical line (18). The couplers have capacitive circuits serially connected with an air-core or dielectric-core transformer (22). The capacitive circuits resonate with the transformer (22) at a preselected frequency. The coupler (28) eliminates noise and is matched to the characteristic impedance of the line at the preselected frequency, which linearizes communication on the line and allows high speed data and voice communication over long distances. Multiple modulators and demodulators are used to produce multiple modulated carrier frequencies. |