Abstract: A sigma-delta modulator (400) 400, 500, 600) for converting an input signal (X(s)) (X(s)) to a quantized output signal (Y(z)) (Y(z)), in which a feedback loop is provided between a filter (402) and a quantizer (403) of the modulator, the feedback loop configured to reduce quantization errors from the modulator by filtering and subtracting quantization noise fed back to an input of the quantizer (403).

Abstract: The present invention relates to a circuit and a method for jitter compensation in a receiver system and for improving the SNR and/or the BER performance. The circuit for jitter compensation comprises: a combiner block (600) for combining a reference signal with an input signal (Sin) of said circuit (700, 900, 1000); a converter stage (605) for converting said input signal (Sin) together with said reference signal, said converter stage (605) being clocked by a clock signal modulated by a jitter signal; a forward path (631) having a first mixer unit (610) for multiplying a copy of an output signal (A) of said converter stage (605) with the frequency of said reference signal for generating a jitter compensating signal (B); and a compensation unit (608) for compensating jitter in said output signal (A) of said converter stage (605) in a direct output path (632) with said jitter compensating signal (B).

Abstract: A method is disclosed of compensating the output of an ADC for non-linearity in the response of the ADC. The method comprises converting an analog input signal to uncorrected digital ADC output samples, applying a vector of correction variables to each of a block of uncorrected ADC output samples to provide a block of corrected ADC samples, and iteratively minimizing a measure of the spectral flatness of the block of corrected ADC samples with response to the vector of correction variables.

Abstract: An analog to digital conversion circuit comprises a first digital noise cancellation filter (16) configured to provide a signal to cancel quantization noise from an analog to digital converted output signal. In a calibration phase a second digital noise cancellation filter (26) is has an input coupled to an input of the first digital noise cancellation filter (16). Mutually different sets of at least one-filter coefficients are programmed in the first and second digital noise canceling filters (16, 26). A difference is computed of averaged size indications of digital output signals derived using signals from the first and second digital noise cancellation filters (16, 26) using the same input signal. Updates of the sets of at least one filter coefficients are adapted dependent on the difference between the averaged size indications.

Abstract: An analog to digital conversion circuit comprises a first digital noise cancellation filter (16) configured to provide a signal to cancel quantization noise from an analog to digital converted output signal. In a calibration phase a second digital noise cancellation filter (26) is has an input coupled to an input of the first digital noise cancellation filter (16). Mutually different sets of least one-filter coefficients are programmed in the first and second digital noise canceling filters (16, 26). A difference is computed of averaged size indications of digital output signals derived using signals from the first and second digital noise cancellation filters (16, 26) using the same input signal. Updates of the sets of at least one filter coefficients are adapted dependent on the difference between the averaged size indications.

Abstract: An electronic quadrature device is provided comprising at least one I signal path (I) and at least one Q signal path (Q); at least one first sigma-delta modulator (DSDMI) and at least one first digital/analog converter unit (DACI) arranged in the at least one I signal path (I); and at least one second sigma-delta modulator (DSDMQ) and at least one second digital/analog converter unit (DACQ) arranged in the at least one Q signal path (Q). The at least one first sigma-delta modulator (DSDMI) is coupled to the at least one second sigma-delta modulator (DSDMQ) via at least one complex signal path (C1-C4) to implement a complex filter.