Abstract: Systems and methods provide analog delay elements, which may be utilized in isolation or in a cascade. For example, a delay element may include a broadband amplifier and a passive, programmable filter, which may provide a desired magnitude and group delay response over a wide frequency range while being tolerant of process variations.

Abstract: A decision feedback equalizer with dynamic feedback control for use in an adaptive signal equalizer. Timing within the decision feedback loop is dynamically controlled to optimize recovery of the data signal by the output signal slicer.

Abstract: An apparatus and method for adaptively introducing a compensating signal latency related to a signal latency of a data symbol decision circuit. Adaptive timing control circuitry, including an interpolating mixer implemented as a tapped delay line with correlated tap coefficients, introduces a latency adaptively and substantially matching the latency of the data decision circuit for use within an adaptive equalizer, thereby minimizing the mean-squared error of such decision circuit. This adaptive latency is used in generating the feedback error signal which, in turn, can be used by the feedforward equalizer for dynamically adjusting its adaptive filter tap coefficients.

Abstract: An apparatus and method for adaptively introducing a compensating signal latency related to a signal latency of a data symbol decision circuit. Adaptive timing control circuitry, including an interpolating mixer implemented as a tapped delay line with correlated tap coefficients, introduces a latency adaptively and substantially matching the latency of the data decision circuit for use within an adaptive equalizer, thereby minimizing the mean-squared error of such decision circuit. This adaptive latency is used in generating the feedback error signal which, in turn, can be used by the feedforward equalizer for dynamically adjusting its adaptive filter tap coefficients.

Abstract: An adaptive signal equalizer with a feedforward filter in which the feedback error signal and corresponding incoming data signal are dynamically aligned in time using signal interpolation, and further, to control the precursor/postcursor filter taps configuration, thereby producing more adaptive filter tap coefficient signals for significantly improved and robust signal equalization.

Abstract: An adaptive coefficient signal generator for use in an adaptive signal equalizer with fractionally-spaced feedback. The signals representing the feedback tap coefficients are generated in conjunction with a timing interpolation parameter such that the fractionally-spaced feedback circuitry dynamically emulates symbol-spaced feedback circuitry.

Abstract: An adaptive coefficient signal generator for use in an adaptive signal equalizer with fractionally-spaced feedback. The signals representing the feedback tap coefficients are generated in conjunction with a timing interpolation parameter such that the fractionally-spaced feedback circuitry dynamically emulates symbol-spaced feedback circuitry.

Abstract: An adaptive signal equalizer with a feedforward filter in which the feedback error signal and corresponding incoming data signal are dynamically aligned in time using signal interpolation, and further, to control the precursor/postcursor filter taps configuration, thereby producing more adaptive filter tap coefficient signals for significantly improved and robust signal equalization.

Abstract: Techniques and devices for controlling or compensating for both the first-order and high-order PMD effects in an optical signal by processing the signal in a fixed DGD stage and a variable DGD stage in sequence.

Abstract: Techniques and systems for mitigating polarization-related signal degradation or distortions in birefringent optical links based on intra-bit polarization diversity modulation.

Abstract: Techniques for monitoring frequency-dependent parameter and optical property such as optical dispersion in a modulated optical signal with sidebands based on optical vestigial sideband filtering. Monitoring implementations for both chromatic dispersion and polarization-mode dispersion are described as examples.

Abstract: Techniques and devices for controlling or compensating for both the first-order and high-order PMD effects in an optical signal by processing the signal in a fixed DGD stage and a variable DGD stage in sequence.