155 results about "Sigma delta modulation" patented technology

An optical recording disk has audio signals recorded as data encoded in accordance with DVD specifications, both as PCM data and as single bit stream data that are generated by sigma-delta modulation, thereby providing both the improved audio reproduction capability of single bit stream data and also compatibility with existing types of DVD playback apparatus. Data are recorded using proposed new DVD stream modes, having 10 data channels, 48 kHz PCM sampling frequency and 16 or 20 bits/sample, with the ratio (2:8) of data channel capacities allocated to the PCM data and single bit stream data being made identical to the ratio of the respective bit rates at which the PCM data and single bit stream data are generated.

A sigma-delta modulation sensing circuit and an analog-to-digital converter for an imager that eliminate the erroneous conversion of non-zero analog voltages to zero digital voltages is provided. The sensing circuit includes an offset branch that allows input of an offset voltage that is at least as large as a negative channel-specific offset found in a pixel signal voltage. The sensing circuit also includes a regulation branch based on a reference voltage common across multiple columns of an imager. The regulation branch has an adjustable resistance that is modulated during the sensing operation, which creates an adjustment current that is applied during the sensing operation to a reset signal. The sensing circuit and analog-to-digital converter generate digital code based on the difference between the reset voltage and the summed offset and pixel signal voltage.

Methods and apparatus are provided for efficiently amplifying or converting a signal. An input signal is decomposed into a plurality of two state signals, each two state signal having a respective on level and off level. This may involve sigma-delta modulation and phase splitting. For amplifier applications, each of the two state signals is amplified with a respective switching power amplifier to produce a respective amplified signal. The amplified signals are combined to produce an amplified version of the input signal. Signals may be adjusted for impairments associated with a subsequent processing operation such as the combining.

A transmitting circuit apparatus has a frequency modulator that performs frequency modulation of a carrier wave with frequency modulation data and outputs the frequency-modulated carrier wave; a sigma-delta modulator which performs sigma delta modulation of amplitude modulation data; and an amplitude modulator that performs amplitude modulation of the frequency-modulated carrier wave with an output signal of the sigma-delta modulator and outputs the amplitude-modulated carrier wave.

A system and/or method for sensing the presence of moisture (e.g., rain) and/or other material(s) on a window such as a vehicle window (e.g., vehicle windshield, sunroof or backlite). In certain example embodiments of the invention, at least one sensing capacitor is supported by a window such as a vehicle windshield, the capacitor(s) having a field that is affected by moisture (e.g., rain) on a surface of the window. A sensing circuit outputs an analog signal that is based on and/or related to the capacitance(s) of the sensing capacitor(s). The analog output of the circuit may be converted to a digital signal via sigma-delta modulation, and subjected to processing (e.g., correlation) for determining whether moisture (e.g., rain, dew, fog, etc.) or the like is present on the surface of the window.

The invention relates to a full-digitalized super-directivity speaker system based on multi-bit sigma-delta modulation. The system comprises a sound source, a digital input interface, a carrier wave modulator, an interpolation filter, a sigma-delta modulator, a thermometer encoder, a dynamic mismatch reshaper, a multi-channel digital amplifier and an ultrasonic transducer array. The system can achieve full digitalization of a system signal transmission link, highly integrated design can be carried out conveniently, system size and power consumption are reduced, system manufacturing complexity and cost are lowered, system electro-acoustic conversion efficiency is improved, and the system has low electromagnetic radiation level and good antijamming capability at the same time, can well lower the harmonic distortion level for demodulating a sound source signal, and greatly improve articulation clearness of conveyed information and acoustic level. The system has a good sound field control ability, provides a good realization method for voice private conveying, and can better meet development requirements of digitalization and networking at the same time.

Low-cost switching converter systems are provided which combine analog generation of a current signal with digital generation of a loop error signal that is realized with a control loop that includes a high-resolution, low-bandwidth sigma-delta modulator and a low-resolution digital-to-analog converter. The current signal and error signal are differenced to provide a control signal to the switching converter. This economical system structure facilitates quick and easy digital alteration of system parameters (e.g., loop compensation and voltage reference). System embodiments add a high-frequency analog feedback path in parallel with the control loop to supplement and enhance its control performance.

A sigma-delta modulator includes a processing circuit, a quantizer, a truncater and a feedback circuit. The processing circuit receives an input signal and an analog information and generates an integrated signal by perform an integration upon a difference between the input signal and the analog information. The quantizer includes a successive approximation register (SAR) analog-to-digital converter (ADC) for receiving the integrated signal and generating a digital information according to the integrated signal. The truncater receives the digital information and generates a truncated information according to the digital information. The feedback circuit generates the analog information to the processing circuit according to the truncated information, wherein an order of the truncater is lower than an order of the integration.

The invention discloses a system and a method for metering and analyzing electric energy as well as an analog-to-digital conversion circuit, belonging to the field of intelligent grid. In the invention, two sampling units are simultaneously connected behind a sigma-delta modulation unit, wherein the D value of the first sampling unit is fixed for metering the electric energy and the D value of the second sampling unit is variable for analyzing sub-harmonic waves so as to improve the monitoring stability of the sub-harmonic waves and ensure the accuracy for metering the electric energy in the cost of less hardware. During variation of the grid frequency, the D value of the second sampling unit is automatically calculated and adjusted to realize self-adaptive adjustment and maintain the monitoring stability of sub-harmonic waves. Coefficient compensation is performed on the harmonic component in the second sampling unit so as to avoid attenuation of a transition zone of a medium-high frequency part resulting from using a 3-order CIC (Cascaded Integrator Comb) filter.

The inveniton relates to a digital time-interleaved RF-PWM transmitter. The method for transmitting radio frequency (RF) signals is provided. In-phase (I) and quadrature (Q) signals are received and filtered using sigma-delta modulation. I and Q pulse width modulation signals are generated from the filtered I and Q signals and interleaved so as to generate a time-interleaved signal. The time-interleaved signal is then amplified to generate the RF signals.

A class D power amplifier is provided to drive a low impedance load for audio applications. The amplifier includes a sigma-delta modulator circuit including three or more integrators that are arranged for third or higher order sigma-delta modulation. Also, the sigma-delta modulator circuit includes a quantizer circuit that is arranged to provide a sigma-delta modulator output signal based on a three-level switching scheme. The class D power amplifier drives a speaker based on the three-level switching scheme so that the output switches between three levels: VDD, 0, and −VDD, based on the input signal.

The invention provides an oversampling 64-time sigma-delta modulation circuit with an effective bit being 18. The circuit comprises an interpolation filter and a sigma-delta modulator. The interpolation filter is used for conducting oversampling interpolation and filtering on digital input signals. The input end of the sigma-delta modulator is connected with the output end of the interpolation filter, the sigma-delta modulator is used for modulating oversampled digital signals, shaping quantized noise introduced by a quantizer, moving noise in the signal bandwidth out of the bandwidth, and meanwhile guaranteeing that transmission of the signals is not affected, and output 1-bit 0/1 code streams need to be restored through a backward-stage analog reconstruction filter so as to acquire analog signals. An improved structure is adopted in a half-band filter in the interpolation filter so that the area of the half-band filter can be greatly reduced; for the sigma-delta modulator, a monocycle high-order structure easier to achieve is adopted, the stability problem is analyzed, the high signal to noise ratio is achieved, and meanwhile stability of the modulator is guaranteed.

A method and apparatus for converting a high precision digital word into a high precision analog signal is disclosed. A sigma delta modulator applies a digital input signal to a dither signal to generate a combined signal for sampling. A digital-to-analog converter quantizes the combined signal. An analog filter provides a cutoff at a bandwidth of interest to remove out of band quantization noise and signals. An I transfer function and a Q transfer function can be coupled between the sigma delta modulator and the digital-to-analog converter for mapping of the combined signal. The apparatus can also include a phase interpolator for receiving the output signal and outputting a clock recovery phase.

A system for converting digital signals into analog signals using sigma-delta modulation and includes a signed thermometer encoder for converting a plurality of signed binary data received at the encoder into a plurality of signed thermometer data and a rotational dynamic element matching (DEM) arrangement for receiving the plurality of signed binary data and the plurality of signed thermometer data. The rotational DEM arrangement further includes a first barrel shifter for receiving a positive thermometer data at a cycle, the first barrel shifter having a first pointer indicating a starting position of next positive thermometer data, and a second barrel shifter for receiving a negative thermometer data at a cycle, the second shifter having a second pointer indicating a starting position of next negative thermometer data, wherein the first pointer is circularly shifted as a function of positive binary data and the second pointer is circularly shifted as a function of negative binary data.

The invention discloses a method and a device for analyzing vector signals. The method includes digitalizing vector modulating signals by means of A/D (analog/digital) conversion for fixed sampling; converting data rates via a decimal extraction module on the basis of the Sigma-delta modulation conversion shaping technology; resampling data; enabling each data rate to be equal to integer multiples of a symbol rate and the number of symbol points; eliminating inter-code interference and digital mantissa modulation jamming by the aid of FIR (finite impulse response) shaping filter; and performing vector demodulation and data restoration to obtain received original information. The digital mantissa modulation jamming is caused by Sigma-delta modulation conversion. The method and the device have the advantages that sampling rates are converted by the Sigma-delta modulation conversion shaping technology, vector modulation signals at different symbol rates can be received, the quality of the signals can be analyzed, and the performance of a receiver is improved.

The invention relates to a broadband tuner based on band pass sigma-delta modulation and a method thereof. The broadband tuner comprises a low noise preamplifier, an anti-aliasing low pass filter and a sigma-delta ADC modulator circuit. The method comprises the following steps: an input signal obtained from an antenna is inputted to the low noise preamplifier of the tuner of the invention; the signal processed by the low noise preamplifier is inputted to the anti-aliasing low pass filter; the signal processed by the anti-aliasing low pass filter is inputted to a band pass sigma-delta modulation circuit for modulation; and after the modulation of the band pass sigma-delta modulator circuit, a digital signal is outputted. The invention utilizes the sigma-delta ADC to sample the input signal, thus an analogue signal can be directly introduced into a digital signal domain, the digital signal is outputted by the tuner, and then reduced frequency processing or filtration processing is carried out on the digital signal, thereby avoiding the defect of integrated level caused by simulating mixed frequency and reduced frequency in the prior art and at the same time, as band pass modulation is used, the broadband of the input signal and the dynamic requirements of the sigma-delta ADC are reduced.