Patent classifications
H03M3/402
Parallel processing of multiple channels with very narrow bandpass digital filtering
A method includes converting, by n analog to digital converter circuits, n analog signals into n first digital signals having a first data rate frequency; converting, by n digital decimation filtering circuits, the n first digital signals into n second digital signals having a second data rate frequency; and converting, by n digital bandpass filter (BPF) circuits, the n second digital signals into a plurality of outbound digital signals having a third data rate frequency. The coefficients for the taps of a digital BPF circuit is set to produce a bandpass region approximately centered at the oscillation frequency of the analog signal and having a bandwidth tuned for filtering a pure tone component of the analog signal. The first data rate frequency is a first integer multiple of the third data rate frequency. The second data rate frequency is a second integer multiple of the third data rate frequency.
SIGNAL MODULATION FOR RADIOFREQUENCY COMMUNICATIONS
A signal modulation device comprising: an input for receiving a complex input signal (106) comprising an in-phase component signal and a quadrature-phase component signal, a sigma-delta modulator (110) for modulating the complex input signal at an oversampling clock rate (F1) into an intermediary signal (112), a numerical oscillator (60) for generating a phase signal (61) oscillating at a selected carrier frequency (FC), wherein the phase signal takes a finite number of quantized states, and a symbol mapping table (114) comprising a predefined quantized symbol for each quantized complex state of the intermediary signal and each quantized state of the phase signal, and operates at each oversampling clock period (F1) to select a quantized symbol (116) as a function of a current quantized complex state of the intermediary signal (112) and a current quantized state of the phase signal (61).
MINIMIZING A DELAY OF A CAPACITANCE-TO-VOLTAGE CONVERTER OF A GYROSCOPE BY INCLUDING SUCH CONVERTER WITHIN A BANDPASS SIGMA-DELTA ANALOG-TO-DIGITAL CONVERTER OF THE GYROSCOPE
Facilitating minimization of non-linearity effects of a delay of a capacitance-to-voltage (C2V) converter on an output of a gyroscope is presented herein. A sense output signal of a sense mass of the gyroscope and a drive output signal of a drive mass of the gyroscope are electronically coupled to respective analog-to-digital converter (ADC) inputs of bandpass sigma-delta ADCs of the gyroscope. The bandpass sigma-delta ADCs include respective C2V converters that are electronically coupled, via respective feedback loops, to the respective ADC inputs to facilitate reductions of respective propagation delays of the bandpass sigma-delta ADCs. Respective ADC outputs of the bandpass sigma-delta ADCs are electronically coupled to demodulator inputs of a demodulator of the gyroscope that transforms the sense output into an output of the MEMS gyroscope representing an external stimulus that has been applied to the sense mass.
Method for Automatic Frequency Adaptation of Filters During Operation in Closed Control Loops
The present invention relates to a method for adjusting the resonance frequency of a loop filter in a delta-sigma modulator, e.g. in an angular rate sensor, to a predetermined frequency value, wherein the sigma-delta modulator comprises an input terminal, which is connected to the loop filter, a quantizer, which is connected to an output of the loop filter, and a feedback branch, which couples an output of the quantizer back to the input terminal. The method comprises the following steps: Optional rough adjustment of the resonance frequency of the filter by means of the regulating variable of a second oscillator, input of a filter input signal of the loop filter into a frequency adjustment circuit, determination of a noise spectrum of the filter input signal in a first frequency band and a second frequency band, wherein the first frequency band and the second frequency band are arranged symmetrically around the predetermined frequency, comparison of the noise spectra and creation of an adjustment signal that leads to a frequency adjustment when the noise spectra deviate from one another, and feedback of the adjustment signal of the frequency adjustment circuit to a control input of the loop filter for setting the filter frequency in response to the comparative result.
Radio frequency bandpass delta-sigma analog-to-digital converters and related methods
Radio-frequency (RF) receivers having bandpass sigma-delta analog sigma analog-to-digital converters (ADC) designed to digitize signals in the RF domain are described. Such bandpass ADCs utilize one or more of the following techniques to enhance noise immunity and reduce power consumption: generation of in-phase (I) and quadrature (Q) paths in the digital domain, n.sup.th order resonant bandpass filtering with n>1, and signal sub-sampling in an i.sup.th Nyquist zone with i>1. Compared to RF receivers in which the I and Q paths are generated in the analog domain, these RF receivers exhibit higher IRRs because they are not susceptible to in-phase/quadrature (IQ) mismatch. Using n.sup.th order resonant bandpass filtering with n>1 attenuates unwanted image tones. The bandpass ADC-based RF receivers described herein exhibit enhanced immunity to noise, achieving for example image rejection ratios (IRR) in excess of 95 dB.
DATA SENSING CIRCUIT WITH PARALLEL DIGITAL FILTER PROCESSING
A data sensing circuit includes one or more drive sense circuits operably coupled to a plurality of data sources. The one or more drive sense circuits produces a plurality of digital sense signals regarding the plurality of data sources at an oversampling rate. The data sensing circuit further includes a digital filtering circuit operably coupled to receive, in parallel, at least some of the plurality of digital sense signals and generate, in a serial manner, a plurality of affect values from the least some of the plurality of digital sense signals.
SYSTEMS AND METHODS FOR DELTA-SIGMA DIGITIZATION
A baseband processing unit includes a baseband processor configured to receive a plurality of component carriers of a radio access technology wireless service, and a delta-sigma digitization interface configured to digitize at least one carrier signal of the plurality of component carriers into a digitized bit stream, for transport over a transport medium, by (i) oversampling the at least one carrier signal, (ii) quantizing the oversampled carrier signal into the digitized bit stream using two or fewer quantization bits.
CONTROLLER WITH PARALLEL DIGITAL FILTER PROCESSING
A method includes converting, by n analog to digital converter circuits, n analog signals into n first digital signals having a first data rate frequency; converting, by n digital decimation filtering circuits, the n first digital signals into n second digital signals having a second data rate frequency; and converting, by n digital bandpass filter (BPF) circuits, the n second digital signals into a plurality of outbound digital signals having a third data rate frequency. The coefficients for the taps of a digital BPF circuit is set to produce a bandpass region approximately centered at the oscillation frequency of the analog signal and having a bandwidth tuned for filtering a pure tone component of the analog signal. The first data rate frequency is a first integer multiple of the third data rate frequency. The second data rate frequency is a second integer multiple of the third data rate frequency.
Receiver and time-of-flight system with high dynamic range having a coupling capacitor respectively connected to a photodiode and a sigma delta analog to digital converter
The disclosure provides a receiver with high dynamic range. The receiver includes a photodiode that generates a current signal. A coupling capacitor is coupled to the photodiode, and generates a modulation signal in response to the current signal received from the photodiode. A sigma delta analog to digital converter (ADC) is coupled to the coupling capacitor, and generates a digital data in response to the modulation signal. A digital mixer is coupled to the sigma delta ADC, and generates an in-phase component and a quadrature component corresponding to the digital data. A processor is coupled to the digital mixer, and processes the in-phase component and the quadrature component corresponding to the digital data.
Minimizing a delay of a capacitance-to-voltage converter of a gyroscope by including such converter within a bandpass sigma-delta analog-to-digital converter of the gyroscope
Facilitating minimization of non-linearity effects of a delay of a capacitance-to-voltage (C2V) converter on an output of a gyroscope is presented herein. A sense output signal of a sense mass of the gyroscope and a drive output signal of a drive mass of the gyroscope are electronically coupled to respective analog-to-digital converter (ADC) inputs of bandpass sigma-delta ADCs of the gyroscope. The bandpass sigma-delta ADCs include respective C2V converters that are electronically coupled, via respective feedback loops, to the respective ADC inputs to facilitate reductions of respective propagation delays of the bandpass sigma-delta ADCs. Respective ADC outputs of the bandpass sigma-delta ADCs are electronically coupled to demodulator inputs of a demodulator of the gyroscope that transforms the sense output into an output of the MEMS gyroscope representing an external stimulus that has been applied to the sense mass.