Vrije Universiteit Brussel

Eqcologic N.v.

Xavier Maillard

Maarten Kuijk

Koen Van Den Brande

An active bidirectional splitter () for transmission and reception of data signals over a single ended transmission medium () comprises an input port (), an output port () and a differential combined input/output port (), a first differential output driver () for receiving an input signal () from the input port () and transmitting this signal to the differential input/output port (), a second differential output driver () for receiving the input signal () from the input port (), a first averaging circuit () for averaging the differential signal () at the differential input/output port (), a second averaging circuit () for averaging the differential signal () at the output of the second differential output driver (), and a receiver () for receiving both averaged signals () from the first averaging circuit () and the second averaging circuit () and for generating therefrom an output signal on the output port ().

Active bidirectional splitter for single ended media

The present invention is related to an adaptive equalizer comprising multiple tuning circuits that generate tuning signals. Each tuning signal can typically induce higher frequency gain up to a limited level, e.g. +5 dB, at the upper data frequency for compensation of high frequency losses in the connected transmission channel. Several tuning signals can tune one adaptive amplifying compensation stage. In its adaptive amplifying compensation stage the tuning signal can generate through its tuning function, non-linear small-signal and large-signal transfer behavior. However, by limiting the amount of higher frequency gain to maximum +8 dB per tuning function, and by having only one tuning function active at a time the resulting deterministic fitter remains tolerable. Several adaptive amplifying compensation stages introducing non-linear effects in the compensation behavior and their tuning functions are disclosed. Especially at low power supply voltage the merits of the present invention become apparent.

Low voltage multistage adaptive equalizer

The present invention provides an equalizer filter for compensating a received distorted signal for frequency dependent signal modifications introduced by a transmission channel, the received signal having an amplitude. The filter comprises at least one amplifying compensation stage having a gain and a saturation level, at least one limiting amplifier, and gain control means for controlling the gain of the at least one amplifying compensation stage, the gain control means comprising at least one comparator circuit comparing filtered input and output signals of the limiting amplifier, the at least one comparator circuit comprising a bias current source. The bias current source is adapted to deliver a variable current.

Multistage tuning-tolerant equalizer filter with improved detection mechanisms for lower and higher frequency gain loops

A multistage equalizer filter for compensating a received distorted signal having an amplitude for frequency dependent signal modifications introduced by a transmission channel includes at least one amplifying compensation stage having a gain and a saturation level, the gain being monotonically rising for at least a last decade in frequency below an upper data frequency of the received signal, and a gain control device for controlling the gain of the amplifying compensation stage such that the amplitude of the received signal amplified in the at least one amplifying compensation stage remains below the saturation level of the amplifying compensation stage. The gain may be regulated by separately regulating low frequency gain, mid-frequency gain and higher frequency gain for each of the at least one amplifying compensation stages.

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Pepingen, Belgium

Xavier Maillard