Patent classifications
H03M3/502
Mixed-mode Millimeter-wave Transmitter
A radio frequency (RF) transmitter includes a set of input ports to receive baseband samples of a signal to be transmitted on a set of disjoint frequency bands, a set of filter banks, there is one filter bank for each input port, each filter bank includes a plurality of digital polyphase interpolation filters to sample a shifted phase of the corresponding sequence of baseband samples and to interpolate the sampled phases to produce a plurality of sequences of interpolated baseband phased samples with the shifted phase, and a set of oscillators banks, each oscillator bank includes a plurality of polyphase Digital Direct Synthesizer (DDS) corresponding to the plurality of digital polyphase interpolation filters to generate a plurality of sequences of samples of digital waveform. The RF transmitter includes a set of mixer banks to mix corresponding sequences of samples of digital waveform and interpolated baseband phased samples to up convert each sequence of interpolated baseband phased samples to the effective frequency, a parallel digital combiner to combine in-phase sequences of interpolated baseband phased samples of different frequency bands to produce a plurality of sequences of multiband upconverted samples, and a pulse encoder to modulate and encode the plurality of sequences of multiband upconverted samples to produce a plurality of encoded multi-band signals. The RF transmitter converts the plurality of encoded multi-band signals into a RF bitstream and radiate the RF bitstream as an analog signal.
High Efficiency Power Amplifier Architectures for RF Applications
A parallel delta sigma modulator architecture is disclosed. The parallel delta sigma modulator architecture includes a signal demultiplexer configured to receive an input signal and to demultiplex the input signal to output a plurality of streams, a plurality of delta sigma modulators executing in parallel, each delta sigma modulator configured to receive a stream from the plurality of streams and to generate a delta sigma modulated output, and a signal multiplexer configured to receive a plurality of delta sigma modulated outputs from the plurality of delta sigma modulators and to multiplex together the plurality of delta sigma modulated outputs into a pulse train.
Method and apparatus for improving resolutions of analog-to-digital converters
An apparatus having an analog-to-digital converter with an increased effective resolution is disclosed. The apparatus includes a signal processing functional block and an analog-to-digital conversion block. The signal processing functional block includes a controller for providing a set of digital control signals according to a set of digital input signals received by the controller, a digital-to-analog converter for converting the digital control signals to a set of corresponding analog control signals, and a physical hardware unit for performing a specific function according to the analog control signals. The analog-to-digital conversion block includes an adder for adding a dither signal to an analog feedback signal originated from the physical hardware unit, an ADC for converting sums of dither signals and analog feedback signals to a set of oversampled digital control signals to be fed into the controller.
Quantizer including capacitors and operating method of quantizer
A quantizer includes: a quantizer capacitor having a first end and a second end; an input calculator that receives input voltages, sums the input voltages, and outputs the summed result to the first end of the quantizer capacitor; a scaler that receives reference voltages and a scale code, generates a scale voltage from the reference voltages depending on the scale code, and outputs the scale voltage to the second end of the quantizer capacitor; and a latch that stores an output voltage of the first end of the quantizer capacitor.
Apparatuses and Methods for Sample Rate Conversion
Provided, among other things, is an apparatus that converts a signal from one sampling domain to another, and which includes: an input line for accepting an input signal and a processing branch. The processing branch includes a branch input coupled to the input line for inputting data samples that are discrete in time and in value, a quadrature downconverter, a first and second lowpass filter, a first and second polynomial interpolator, and a rotation matrix multiplier that provides a phase rotation. The processing branch generates data samples at a sampling interval that differs from the sampling interval associated with the signal provided to the branch input, e.g., with the difference in the sampling intervals depending on fluctuations in the output period of a local oscillator. Certain embodiments include multiple such processing branches, e.g., operating on different frequency bands of the input signal.
SPACE-TIME OVERSAMPLING AND ERROR SHAPING FOR COARSELY QUANTIZED ARRAYS
Methods and apparatus for shaping and filtering quantization errors conjointly in space and time to produce a higher-precision output in a spatially and temporally oversampled array. A space-time error-shaping array system has an array of sensors, each sensor producing a temporal signal comprising quantized waveforms. A multi-input multiple-output (MIMO) discrete-time filter structure with multiple inputs, each coupled to a sensor of the array of sensors, shapes quantization errors of the array of sensors on the basis of temporal aspects of the quantized waveforms conjointly with spatial aspects of the quantized waveforms.
High efficiency power amplifier architectures for RF applications
A parallel delta sigma modulator architecture is disclosed. The parallel delta sigma modulator architecture includes a signal demultiplexer configured to receive an input signal and to demultiplex the input signal to output a plurality of streams, a plurality of delta sigma modulators executing in parallel, each delta sigma modulator configured to receive a stream from the plurality of streams and to generate a delta sigma modulated output, and a signal multiplexer configured to receive a plurality of delta sigma modulated outputs from the plurality of delta sigma modulators and to multiplex together the plurality of delta sigma modulated outputs into a pulse train.
CIRCUIT AND METHOD FOR DIGITAL-TO-ANALOG CONVERSION USING THREE-LEVEL CELLS
A circuit for digital-to-analog conversion using a plurality of 3-level cells includes a circuit for digital-to-analog conversion using a plurality of 3-level cells mutually independently providing positive electricity, providing negative electricity, or floating. The circuit including a preprocess circuit and a shift circuit. The preprocess circuit is configured to receive thermometer code data generated from signed binary data and generate a shift count for shifting a cell pointer pointing to one of the plurality of 3-level cells for dynamic element matching (DEM) from the thermometer code data. The shift circuit is configured to store the cell pointer and shift the stored cell pointer according to the shift count. The shifted cell pointer is shifted in proportion to an absolute value of the binary data in a direction depending on a sign of the binary data.
Interleaved sigma delta modulator based SDR transmitter
A Delta-Sigma modulator architecture is disclosed that uses interleaving and dynamic matching algorithms to address the needs of multi-mode, multi-band high bandwidth transmitters. The proposed architecture also supports a novel software defined transmitter architecture based on an interleaved Delta-Sigma modulator to generate RF signals. The proposed architecture leverages interleaving concepts to relax subcomponent clock rates without changing the effective oversampling ratio, thus, making it easier to reach aggressive dynamic range goals across wider bandwidths at higher frequencies. The DEM algorithm helps to randomize mismatch errors across all interleaved paths and improves substantially the signal-to-noise ratio. Additionally, a tunable bandpass filter can be added to reject out-of-band emissions.
Device for generating analogue signals and associated use
An analog signals generating device comprises a current pump controlled by a control code generated by a module for calculating the digital code with shaping of noise. The calculation module receives as input a digital signal representative of the analog signal to be generated and comprises at least one quantizer and a quantization error compensating stage. The current pump comprises two groups of at least one electric current generator and two groups of at least one switching means, the switching facilities being controlled by the control signal and causing the electric currents to flow between the electric current generators and the inputs of a differential amplifier exhibiting a predominantly capacitive input impedance and connected in series between the two groups of switching means.