Transmitter and receiver circuit
US4736385A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 27, 1987 |
| Grant date | Apr 5, 1988 |
| Priority date | — |
| Expiry date | Jan 27, 2007 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L25/08
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
High frequency transmitter and receiver circuits are AC coupled for party line transmission over coaxial cable where the circuits are connectable to the cable by use of stinger taps and thereby eliminate the need to interrupt service when connecting the circuits to the cable. The transmitter circuit includes oppositely polled current sources which are alternately switched to the coaxial cable via the stinger tap or to a dummy load by current switches connected to data inputs via buffer circuits. A transmit enable circuit controls the current sources to be active or inactive and to prevent unbalances from saturating either current sources. The receiver includes a high input impedance biasing network and buffer amplifier that maintain the high input impedance even when power is off. Capacitance at the tap is reduced by a capacitor drive circuit which feeds input signal back to transmitter blocking diodes and to the trunk tap. A feed ahead network, differentiating network, and another buffer amplifier form a network for recovering the transmitted signal shape regardless of distance from the transmitter. A gated amplifier restores the shaped signal to logic levels ready for conversion …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.