Digital two-to-four wire converter for full duplex signals
Patent 4377858 Issued on March 22, 1983. Estimated Expiration Date: 
October 23, 2000. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.
October 23, 2000. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.Patent ReferencesElectronic hybrid Self-correcting equalization system Automatic equalization for digital transmission systems Auto balancing duplexer for communication lines Patent #: 4320498 InventorApplicationNo. 06/199905 filed on 10/23/1980US Classes:370/276, DUPLEX375/232, Adaptive379/402Hybrid circuitExaminersPrimary: Brigance, Gerald L.Attorney, Agent or FirmInternational ClassesH04B 1/54 (20060101)H04B 1/58 (20060101) H04Q 11/04 (20060101) AbstractA digital electronic hybrid circuit for a telephone line circuit is described wherein the two-to-four wire conversion function is provided with an improved synthesized automatic impedance match between the telephone subscriber line and the digital central office. More particularly, an impedance at the input to the line circuit is simulated without the use of discrete components and which closely matches the subscriber line impedance. The circuit digitally separates the full duplex signals on a two-wire transmission path to a pair of digital signals. | |
