Patent ID: 6977958

Claim:
A loop extender adapted to be coupled to a local loop for improving transmission of downstream and upstream DSL signals over the local loop, the downstream DSL signals traversing the local loop in a downstream direction and having a downstream frequency band, and the upstream DSL signals traversing the local loop in an upstream direction and having an upstream frequency band, the loop extender comprising: a first hybrid coupled to the local loop for receiving downstream DSL signals transmitted over the local loop; a downstream filter/amplifying equalizer coupled to the first hybrid for amplifying the downstream frequency band components of downstream DSL signals received by the first hybrid, and attenuating other components outside the downstream frequency band that may have leaked through the first hybrid; a differential amplifier pair coupled to the downstream filter/amplifying equalizer for further amplifying the downstream DSL downstream frequency band components; a second hybrid coupling the differential amplifier pair to the local loop, the second hybrid differentially amplifying the downstream frequency band components of downstream DSL signals and passing the differentially amplified downstream DSL signals to the local loop; an upstream filter/amplifying equalizer coupled to the second hybrid for amplifying the upstream frequency band components of upstream DSL signals received by the second hybrid, attenuating the downstream frequency band components of upstream DSL signals received by the second hybrid, and passing the attenuated and amplified upstream DSL signals to the first hybrid; and an inverting amplifier coupled to the upstream filter/amplifying equalizer for inverting the attenuated and amplified upstream DSL signals and passing the inverted and amplified upstream DSL signals to the first hybrid.