Pulse or digital communications – Equalizers – Automatic
Patent
1997-02-03
1998-12-01
Bocure, Tesfaldet
Pulse or digital communications
Equalizers
Automatic
375235, H03H 730
Patent
active
058449418
ABSTRACT:
An adaptive equalizer is configured to reconstruct electronic signals which are transmitted over signal cables, such as twisted pair cables. The equalizer satisfactorily reconstructs the signals over a broad range of cable lengths. Using the known degradation characteristics for a cable over a desired range of lengths, the adaptive equalizer includes multiple equalization paths, each of which are configured to reconstruct the input voltage signal optimized for a particular cable length. The degraded input signal is split according to a predetermined relationship into an appropriate two of the multiple equalization paths as controlled by a control logic circuit. Though each path is optimized to reconstruct the signal for a particular length of cable, the adaptive control adds a function of the actual cable length for more accurately reconstructing the signal. Each of the two active paths forms a partially reconstructed signal which is summed to form a composite reconstructed output signal. The control logic circuitry monitors the level of the output signal and adjusts a control signal appropriately in order to maintain the amplitude of the output signal in the required range. The control signal is used to determine the ratio of the input signal between the two active paths. A separate offset correction circuit also monitors the output signal for any offset and provides a correction signal to the input of the equalizer to compensate for the presence of any offset within the signal.
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Mack Michael P.
McBride Kenneth T.
Bocure Tesfaldet
Micro Linear Corporation
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