Patent ID: 7564899

Claim:
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, said filter comprising 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 gain control means 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, wherein said equalizer filter further comprises a comparator means for comparing differential outputs of a first and a second filter coupled to the output node of the last amplifying compensation stage and to the output node of the equalizer filter, wherein the first and second filters are pass-band filters and wherein the comparator means is adapted for generating a comparator signal for adjusting the higher frequency or mid-frequency gain of the at least one amplifying compensation stages.