An optical receiver having an electronic dispersion-compensation module with two parallel signal-processing branches configured to provide a greater range of dispersion compensation than that provided by a prior-art device of comparable implementation complexity. In an example embodiment, each of the signal-processing branches includes a respective bank of finite-impulse-response filters that are configured in accordance with a different respective approximation of the group delay that needs to be compensated. The two group-delay approximations used by the filter banks rely on different respective step functions, each having a respective plurality of quantized steps, with the transitions between adjacent steps in one step function being spectrally aligned with the flat portions of the corresponding steps in the other step function. The filter banks may be further configured to apply different respective frequency-dependent phase-shift and/or amplitude-scaling profiles designed to reduce signal distortions associated with the transitions between adjacent steps in the step functions.