Abstract:
A device for receiving a RF signal (1) is provided. The device comprises an input (3) receiving a RF input signal (2); an analog pre-processing circuitry (11) pre- processing the RF input signal (2); an analog-digitalconverter (8) converting the pre- processed RF input signal to a digital signal (9); and a digital signal processing unit (10) digitallyprocessing the digital signal (9). The digital signal processing unit (10) is adapted to compensate signaldistortions introduced by the analog pre-processing circuitry (11).
Abstract:
A device for receiving an RF input signal (2) and for processing the received RF input signal (2) is provided. The device comprises: an input (3) receiving the RF input signal (2); a clock circuit (34) generating a reference clock signal having a clock circuit specific reference frequency (fclock); and a frequency feedback control loop (17, 18, 20, 21, 22, 23; 35, 37, 38). The frequency feedback control loop is adapted to extract frequency information from the RF input signal (2), to put the clock circuit specific reference frequency (fclock) into relation with the extracted frequency information and to correct for inaccuracies of the clock circuit specific reference frequency based on this relation.
Abstract:
An analog-to-digital converter comprises a signal input (6) for receiving an analog input signal and a set of comparators (4). Each comparator (4) has a first input (21 ) connected to the signal input (6) and a second input (22) connected to a reference voltage (16). Each comparator generates an output based on the comparison of the signals at the first input (21 ) and second input (22). The reference voltage is the same for all comparators. The set of comparators (4) has a non-identical response to the reference voltage (16) and the input signal and is due to an internally arising offset. An adder (25) determines a sum of the outputs of the set of comparators and conversion logic (27) generates an output digital signal dependent on the determined sum. Multiple sets of comparators can be provided, each set having a different respective reference voltage.
Abstract:
A method and device for error optimization in a Digital to Analog Converter (DAC) such as a current-steering DAC, comprising a plurality of selectable unit elements, wherein an input signal represented by a digital input code is converted into a corresponding analog output signal by selecting a plurality of the unit elements in accordance with the input code. The unit elements, for a particular input code, are selected as a result of processing at least one of a group comprising unit element error profile information such as eletrical accuracy of unit elements and turn-on timing errors, input signal type information and output signal type information such to satisfy at least one of a group comprising constraints on the DAC and cost functions.
Abstract:
This invention relates to Analog to Digital Converters (ADC) and, inter alia, to Time Interleaved ADCs and Successive Approximation Register (SAR) ADC's. In a conventional Time Interleaved ADC employing SAR ADC units, the input signal is processed through a track-and-hold circuit (T/H), and then through a buffer circuit, before the SAR ADC unit. There, by means of a comparator, the signal is compared with a Digital-to-Analog Converter (DAC) signal from the SAR logic. The buffer reduces the influence of capacitive loading and physical layout design on the SAR ADC input, but typically has a non-linear response and thus introduces distortion to the input signal. This can limit the ADC linearity, particularly for high-speed ADCs operating with low-supply voltages. An objective of the invention is to reduce or eliminate the effect of the buffer non-linearity. This is done in some embodiments by routing both the signals to the comparator through the same buffer circuit. In another embodiment the DAC signal is routed through a separate second buffer circuit. By use of a single buffer circuit, or where there is ideal matching of the buffer circuits in the latter embodiment, the distortion effects are completely eliminated; however, for practical imperfectly matched buffer circuits according to the latter embodiment, the gain and off-set mismatches can be accommodated through calibration of the buffers or, in suitable applications, through the DAC calibration.
Abstract:
An analog-to-digital converter comprises a signal input (6) for receiving an analog input signal and a set of comparators (4). Each comparator (4) has a first input (21 ) connected to the signal input (6) and a second input (22) connected to a reference voltage (16). Each comparator generates an output based on the comparison of the signals at the first input (21 ) and second input (22). The reference voltage is the same for all comparators. The set of comparators (4) has a non-identical response to the reference voltage (16) and the input signal and is due to an internally arising offset. An adder (25) determines a sum of the outputs of the set of comparators and conversion logic (27) generates an output digital signal dependent on the determined sum. Multiple sets of comparators can be provided, each set having a different respective reference voltage.
Abstract:
A device for receiving a RF signal (1; 21) with loop-through output (16) is provided. The device comprises: an input (3) receiving a RF input signal (2); an analog- digital converter (8) converting the RF input signal (2) to a digital signal (9); a digital signal processing unit (10) digitally processing the digital signal (9); a digital-analog converter (14) converting the processed digital signal (13) to a loop-through RF signal (15) corresponding to the RF input signal (2); and a loop-through output (16) outputting the loop-through RF signal (15).
Abstract:
The present invention relates to a signal processing apparatus comprising a signal input and a signal output; a plurality of signal processing units arranged, wherein each signal processing units having the same structure and at least one spatial error, being connected to the signal input, and being adapted to subject an input signal from the signal input to predetermined signal processing; selection means configured to select and form a predetermined number of groups from the plurality of signal processing units in accordance with a predetermined criterion; and control means for controlling the groups of the signal processing units to be active in a time interleaved schema, wherein an active group provides a respective processed input signal as an output signal to the signal output; wherein the plurality of signal processing units comprises more signal processing units as required to realize a predetermined time interleaving factor.
Abstract:
A multi-channel receiver comprising an ADC and a multi-band, multi-channel selector. The ADC converts a broad-band multi-channel signal into a digital signal. The digital signal is then broken into sub-bands each containing a plurality of channels. A channel selector selects desired channels from the appropriate sub-band. The multi-channel receiver may deliver simultaneous channels equal to the number of channel selectors that have been implemented. The multi-channel receiver may be implemented on a single integrated circuit.
Abstract:
A time-interleaved signal converter (800) comprising a plurality of analogue-to- digital converters (ADCO-3), hereinafter termed ADCs, the ADCs being configured to sample an input signal at a common sampling rate and at differing phases to produce a corresponding plurality of digital signal outputs, the signal converter (800) being configured to produce a combined digital signal output from a combination of the plurality of digital signal outputs, wherein the signal converter (800) is configured to determine a sampling timing error (ΔT) between a pair of the ADCs by comparing an autocorrelation (710) of the combined digital signal output with a cross-correlation (720) of a respective pair of the plurality of digital signal outputs.