Provided are, among other things, systems, apparatuses methods and techniques for converting digital data to radio-frequency (RF) signals. One such apparatus includes a reactive-impedance network within which the levels of multiple binary waveforms are individually boosted, before being combined to produce a single, composite output signal.
H04B 1/00 - Details of transmission systems, not covered by a single one of groups Details of transmission systems not characterised by the medium used for transmission
H03F 1/56 - Modifications of input or output impedances, not otherwise provided for
H03F 3/195 - High-frequency amplifiers, e.g. radio frequency amplifiers with semiconductor devices only in integrated circuits
H03F 3/217 - Class D power amplifiersSwitching amplifiers
Provided are, among other things, systems, apparatuses, methods and techniques for driving a differential transmission line and an associated differential load. One such apparatus includes an input data line; an output data line; positive and negative supply rails; a pair of source termination resistors coupled to the positive supply rail; a first pair of n-channel transistors coupled to the source resistors and to the output data line; and a second pair of n-channel transistors coupled to the output line and to the negative supply rail.
Provided are, among other things, systems, apparatuses methods and techniques for converting digital data to radio-frequency (RF) signals. One such apparatus includes a reactive-impedance network within which the levels of multiple binary waveforms are individually boosted, before being combined to produce a single, composite output signal.
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.
H03M 7/32 - Conversion to or from delta modulation, i.e. one-bit differential modulation
H03M 7/36 - Conversion to or from differential modulation with several bits, i.e. the difference between successive samples being coded by more than one bit
Provided, among other things, is an apparatus for digitally processing a discrete-time signal that includes: an input line for accepting an input signal, processing branches coupled to the input line, and an adder coupled to outputs of the processing branches. First and second lowpass filters, each having a frequency response with a magnitude that varies approximately with frequency according to a product of raised functions, are included within baseband processors in such processing branches.
Provided, among other things, is an apparatus for digitally processing a discrete-time signal that includes: an input line for accepting an input signal, processing branches coupled to the input line, and an adder coupled to outputs of the processing branches. First and second lowpass filters, each having a frequency response with a magnitude that varies approximately with frequency according to a product of raised functions, are included within baseband processors in such processing branches.
Provided are, among other things, systems, apparatuses methods and techniques for automatically adjusting the noise-transfer-function of a modulator which is designed to attenuate the level of unwanted noise and/or distortion in a particular frequency band, without similarly attenuating the level of a desired signal in the same frequency band. One such apparatus includes a processing block for generating and injecting an explicit reference signal, and a processing block for detecting the amplitude of that reference signal.
Provided are, among other things, systems, apparatuses methods and techniques for changing the sampling rate of a discrete-time signal. One such apparatus includes a plurality of parallel processing paths, with each path comprising multiple storage banks and multiplexing elements that operate at a subsampling rate.
An exemplary apparatus for converting fluctuations in periodicity of an input signal into proportional fluctuations in the amplitude of an output signal includes: an input line for accepting an input signal; a delay element with an input coupled to the input line and an output; a detector having a first input coupled to the input line, a second input coupled to the output of the delay element, and an output; an integrator having an input coupled to the output of the detector and an output; and an output line coupled to the output of the integrator. The delay element introduces a time delay which is greater than zero and less than twice the nominal oscillation period of the input signal. The detector performs a differencing operation. The integrator has a time constant of integration that is smaller than twice the delay applied by the delay element.
H03M 1/06 - Continuously compensating for, or preventing, undesired influence of physical parameters
H03L 7/191 - Indirect frequency synthesis, i.e. generating a desired one of a number of predetermined frequencies using a frequency- or phase-locked loop using a frequency divider or counter in the loop a time difference being used for locking the loop, the counter counting between fixed numbers or the frequency divider dividing by a fixed number using at least two different signals from the frequency divider or the counter for determining the time difference
H03K 19/21 - EXCLUSIVE-OR circuits, i.e. giving output if input signal exists at only one inputCOINCIDENCE circuits, i.e. giving output only if all input signals are identical
10.
Conversion of a discrete-time quantized signal into a continuous-time, continuously variable signal
Provided are, among other things, systems, apparatuses, methods and techniques for converting a discrete-time quantized signal into a continuous-time, continuously variable signal. An exemplary converter preferably includes: (1) multiple oversampling converters, each processing a different frequency band, operated in parallel; (2) multirate (i.e., polyphase) delta-sigma modulators (preferably second-order or higher); (3) multi-bit quantizers; (4) multi-bit-to-variable-level signal converters, such as resistor ladder networks or current source networks; (5) adaptive nonlinear, bit-mapping to compensate for mismatches in the multi-bit-to-variable-level signal converters (e.g., by mimicking such mismatches and then shifting the resulting noise to a frequently range where it will be filtered out by a corresponding bandpass (reconstruction) filter); (6) multi-band (e.g., programmable noise-transfer-function response) bandpass delta-sigma modulators; and/or (7) a digital pre-distortion linearizer (DPL) for canceling noise and distortion introduced by an analog signal bandpass (reconstruction) filter bank.
Provided are, among other things, systems, apparatuses, methods and techniques for converting a discrete-time quantized signal into a continuous-time, continuously variable signal. An exemplary converter preferably includes: (1) multiple oversampling converters, each processing a different frequency band, operated in parallel; (2) multirate (i.e., polyphase) delta-sigma modulators (preferably second-order or higher); (3) multi-bit quantizers; (4) multi-bit-to-variable-level signal converters, such as resistor ladder networks or current source networks; (5) adaptive nonlinear, bit-mapping to compensate for mismatches in the multi-bit-to-variable-level signal converters (e.g., by mimicking such mismatches and then shifting the resulting noise to a frequently range where it will be filtered out by a corresponding bandpass (reconstruction) filter); (6) multi-band (e.g., programmable noise-transfer-function response) bandpass delta-sigma modulators; and/or (7) a digital pre-distortion linearizer (DPL) for canceling noise and distortion introduced by an analog signal bandpass (reconstruction) filter bank.
Provided are, among other things, systems, apparatuses, methods and techniques for converting a continuous-time, continuously variable signal into a sampled and quantized signal. One such apparatus includes an input line for accepting an input signal that is continuous in time and continuously variable, multiple processing branches coupled to the input line, and an adder coupled to outputs of the processing branches, with each of the processing branches including a bandpass noise-shaping circuit, a sampling/quantization circuit coupled to an output of the bandpass noise-shaping circuit, a digital bandpass filter coupled to an output of the sampling/quantization circuit, and a line coupling an output of the sampling/quantization converter circuit back into the bandpass noise-shaping circuit. A center frequency of the digital bandpass filter in each processing branch corresponds to a stopband region in a quantization noise transfer function for the bandpass noise-shaping circuit in the same processing branch.
Provided are, among other things, systems, apparatuses, methods and techniques for converting a discrete-time quantized signal into a continuous-time, continuously variable signal. An exemplary converter preferably includes: (1) multiple oversampling converters, each processing a different frequency band, operated in parallel; (2) multirate (i.e., polyphase) delta-sigma modulators (preferably second-order or higher); (3) multi-bit quantizers; (4) multi-bit-to-variable-level signal converters, such as resistor ladder networks or current source networks; (5) adaptive nonlinear, bit-mapping to compensate for mismatches in the multi-bit-to-variable-level signal converters (e.g., by mimicking such mismatches and then shifting the resulting noise to a frequently range where it will be filtered out by a corresponding bandpass (reconstruction) filter); (6) multi-band (e.g., programmable noise-transfer-function response) bandpass delta-sigma modulators; and/or (7) a digital pre-distortion linearizer (DPL) for canceling noise and distortion introduced by an analog signal bandpass (reconstruction) filter bank.
Provided are, among other things, systems, apparatuses methods and techniques for generating discrete-time sinusoidal sequences. One such apparatus includes a plurality of parallel processing branches, with each of the parallel processing branches operating at a subsampled rate and utilizing a recursive filter to generate sub-rate samples which represent a different subsampling phase of a complete signal that is output by the apparatus.
Provided are, among other things, systems, methods and techniques for converting a continuous-time, continuously variable signal into a sampled and quantized signal. According to one implementation, an apparatus includes multiple processing branches, each including: a bandpass noise-shaping circuit, a sampling/quantization circuit, and a digital bandpass filter. A combining circuit then combines signals at the processing branch outputs into a final output signal. The bandpass noise-shaping circuits include adjustable circuit components for changing their quantization-noise frequency-response minimum, and the digital bandpass filters include adjustable parameters for changing their frequency passbands.
Provided are, among other things, systems, apparatuses methods and techniques for attenuating the level of unwanted noise and/or distortion in a particular frequency band, without similarly attenuating the level of a desired signal in the same frequency band. One such apparatus includes a distributed network comprising a plurality of reactive impedance segments and gain cells that form transmission paths, over which continuous and quantized versions of an input signal propagate before combining with the input signal itself.
Provided are, among other things, systems, methods and techniques for converting a continuous-time, continuously variable signal into a sampled and quantized signal. According to one implementation, an apparatus includes multiple processing branches, each including: a continuous-time quantization-noise-shaping circuit, a sampling/quantization circuit, and a digital bandpass filter. A combining circuit then combines signals at the processing branch outputs into a final output signal. The continuous-time quantization-noise-shaping circuits include adjustable circuit components for changing their quantization-noise frequency-response minimum, and the digital bandpass filters include adjustable parameters for changing their frequency passbands.
Provided are, among other things, systems, apparatuses methods and techniques for providing a complete output signal from a set of partial signals, which in turn have been generated by parallel processing paths in the time-interleaved and/or frequency-interleaved conversion of discrete signals to linear signals (i.e., discrete-to-linear conversion). One such apparatus includes a distributed network comprising a plurality of ladder networks through which input signals propagate before being combined to form an output signal.
Provided are, among other things, systems, apparatuses, methods and techniques for converting a continuous-time, continuously variable signal into a sampled and quantized signal. One such apparatus includes an input line for accepting an input signal that is continuous in time and continuously variable, multiple processing branches coupled to the input line, and an adder coupled to outputs of the processing branches. Each of the processing branches includes a continuous-time quantization-noise-shaping circuit, a sampling/quantization circuit coupled to an output of the continuous-time quantization-noise-shaping circuit, a digital bandpass filter coupled to an output of the sampling/quantization circuit, and a line coupling an output of the digital-to-analog converter circuit back into the continuous-time quantization-noise-shaping circuit. A center frequency of the digital bandpass filter in each the processing branch corresponds to a minimum in a quantization noise transfer function for the continuous-time quantization-noise-shaping circuit in the same processing branch.
Provided are, among other things, systems, apparatuses, methods and techniques for converting a discrete-time quantized signal into a continuous-time, continuously variable signal. An exemplary converter preferably includes: (1) multiple oversampling converters, each processing a different frequency band, operated in parallel; (2) multirate (i.e., polyphase) delta-sigma modulators (preferably second-order or higher); (3) multi-bit quantizers; (4) multi-bit-to-variable-level signal converters, such as resistor ladder networks or current source networks; (5) adaptive nonlinear, bit-mapping to compensate for mismatches in the multi-bit-to-variable-level signal converters (e.g., by mimicking such mismatches and then shifting the resulting noise to a frequently range where it will be filtered out by a corresponding bandpass (reconstruction) filter); (6) multi-band (e.g., programmable noise-transfer-function response) bandpass delta-sigma modulators; and/or (7) a digital pre-distortion linearizer (DPL) for canceling noise and distortion introduced by an analog signal bandpass (reconstruction) filter bank.
Provided are, among other things, systems, apparatuses methods and techniques for attenuating the level of unwanted noise and/or distortion in a particular frequency band, without similarly attenuating the level of a desired signal in the same frequency band. One such apparatus includes a distributed network comprising a plurality of reactive impedance segments and gain cells that form transmission paths, over which continuous and quantized versions of an input signal propagate before combining with the input signal itself.
Provided are, among other things, systems, apparatuses methods and techniques for generating discrete-time sinusoidal sequences. One such apparatus includes a plurality of parallel processing branches, with each of the parallel processing branches operating at a subsampled rate and utilizing a recursive filter to generate sub-rate samples which represent a different subsampling phase of a complete signal that is output by the apparatus.
Provided are, among other things, systems, methods and techniques for converting a continuous-time, continuously variable signal into a sampled and quantized signal. According to one implementation, an apparatus includes multiple processing branches, each including: a continuous-time quantization-noise-shaping circuit, a sampling/quantization circuit, and a digital bandpass filter. A combining circuit then combines signals at the processing branch outputs into a final output signal. The continuous-time quantization-noise-shaping circuits include adjustable circuit components for changing their quantization-noise frequency-response minimum, and the digital bandpass filters include adjustable parameters for changing their frequency passbands.
Provided is an apparatus for converting a continuous-time, continuously variable signal into a sampled and quantized signal, which includes an input line for accepting an input signal, multiple processing branches coupled to the input line, and an adder coupled to outputs of the plurality of processing branches. Each of the processing branches includes a sampling/quantization circuit and a digital bandpass interpolation filter having an input coupled to an output of the sampling/quantization circuit. The digital bandpass interpolation filters in different ones of the processing branches have frequency responses that are centered at different frequencies. The digital bandpass interpolation filter in at least one of the processing branches includes: (i) a quadrature downconverter, (ii) a first lowpass filter and a second lowpass filter, (iii) a first interpolator and a second interpolator, each having an input for inputting a variable interpolant value, and (iv) a quadrature upconverter.
Provided are, among other things, systems, apparatuses, methods and techniques for converting a continuous-time, continuously variable signal into a sampled and quantized signal. One such apparatus includes an input line for accepting an input signal that is continuous in time and continuously variable, multiple processing branches coupled to the input line, and an adder coupled to outputs of the processing branches. Each of the processing branches includes a continuous-time quantization-noise-shaping circuit, a sampling/quantization circuit coupled to an output of the continuous-time quantization-noise-shaping circuit, a digital bandpass filter coupled to an output of the sampling/quantization circuit, and a line coupling an output of the digital-to-analog converter circuit back into the continuous-time quantization-noise-shaping circuit. A center frequency of the digital bandpass filter in each the processing branch corresponds to a minimum in a quantization noise transfer function for the continuous-time quantization-noise-shaping circuit in the same processing branch.
Provided are, among other things, systems, apparatuses, methods and techniques for converting a discrete-time quantized signal into a continuous-time, continuously variable signal. An exemplary converter preferably includes: (1) multiple oversampling converters, each processing a different frequency band, operated in parallel; (2) multirate (i.e., polyphase) delta-sigma modulators (preferably second-order or higher); (3) multi-bit quantizers; (4) multi-bit-to-variable-level signal converters, such as resistor ladder networks or current source networks; (5) adaptive nonlinear, bit-mapping to compensate for mismatches in the multi-bit-to-variable-level signal converters (e.g., by mimicking such mismatches and then shifting the resulting noise to a frequently range where it will be filtered out by a corresponding bandpass (reconstruction) filter); (6) multi-band (e.g., programmable noise-transfer-function response) bandpass delta-sigma modulators; and/or (7) a digital pre-distortion linearizer (DPL) for canceling noise and distortion introduced by an analog signal bandpass (reconstruction) filter bank.
Provided are, among other things, systems, apparatuses, methods and techniques for converting a discrete-time quantized signal into a continuous-time, continuously variable signal. An exemplary converter preferably includes: (1) multiple oversampling converters, each processing a different frequency band, operated in parallel; (2) multirate (i.e., polyphase) delta-sigma modulators (preferably second-order or higher); (3) multi-bit quantizers; (4) multi-bit-to-variable-level signal converters, such as resistor ladder networks or current source networks; (5) adaptive nonlinear, bit-mapping to compensate for mismatches in the multi-bit-to-variable-level signal converters (e.g., by mimicking such mismatches and then shifting the resulting noise to a frequently range where it will be filtered out by a corresponding bandpass (reconstruction) filter); (6) multi-band (e.g., programmable noise-transfer-function response) bandpass delta-sigma modulators; and/or (7) a digital pre-distortion linearizer (DPL) for canceling noise and distortion introduced by an analog signal bandpass (reconstruction) filter bank.
Provided are, among other things, systems, methods and techniques for converting a continuous-time, continuously variable signal into a sampled and quantized signal. According to one implementation, an apparatus includes multiple processing branches, each including: a continuous-time quantization-noise-shaping circuit, a sampling/quantization circuit, and a digital bandpass filter. A combining circuit then combines signals at the processing branch outputs into a final output signal. The continuous-time quantization-noise-shaping circuits include adjustable circuit components for changing their quantization-noise frequency-response minimum, and the digital bandpass filters include adjustable parameters for changing their frequency passbands.
Provided is an apparatus for converting a continuous-time, continuously variable signal into a sampled and quantized signal, which includes an input line for accepting an input signal, multiple processing branches coupled to the input line, and an adder coupled to outputs of the plurality of processing branches. Each of the processing branches includes a sampling/quantization circuit and a digital bandpass interpolation filter having an input coupled to an output of the sampling/quantization circuit. The digital bandpass interpolation filters in different ones of the processing branches have frequency responses that are centered at different frequencies. The digital bandpass interpolation filter in at least one of the processing branches includes: (i) a quadrature downconverter, (ii) a first lowpass filter and a second lowpass filter, (iii) a first interpolator and a second interpolator, each having an input for inputting a variable interpolant value, and (iv) a quadrature upconverter.
Provided is, among other things, an apparatus that includes an input line for accepting an input signal that is continuous in time and continuously variable. Multiple processing branches are coupled to the input line, each including: (a) an analog bandpass filter, (b) a sampling/quantization circuit coupled to an output of the analog bandpass filter, and (c) a digital bandpass filter coupled to an output of the sampling/quantization circuit. An adder is coupled to outputs of the processing branches. The digital bandpass filters in different ones of the processing branches have frequency response bandwidths that are centered at different frequencies, and the analog bandpass filters in different ones of the processing branches have frequency responses with bandwidths that are at least 25% greater than the frequency response bandwidths of the digital bandpass filters in their respective processing branches.
Provided are, among other things, systems, apparatuses, methods and techniques for converting a discrete-time quantized signal into a continuous-time, continuously variable signal. An exemplary converter preferably includes: (1) multiple oversampling converters, each processing a different frequency band, operated in parallel; (2) multirate (i.e., polyphase) delta-sigma modulators (preferably second-order or higher); (3) multi-bit quantizers; (4) multi-bit-to-variable-level signal converters, such as resistor ladder networks or current source networks; (5) adaptive nonlinear, bit-mapping to compensate for mismatches in the multi-bit-to-variable-level signal converters (e.g., by mimicking such mismatches and then shifting the resulting noise to a frequently range where it will be filtered out by a corresponding bandpass (reconstruction) filter); (6) multi-band (e.g., programmable noise-transfer-function response) bandpass delta-sigma modulators; and/or (7) a digital pre-distortion linearizer (DPL) for canceling noise and distortion introduced by an analog signal bandpass (reconstruction) filter bank.
Provided are, among other things, systems, apparatuses, methods and techniques for converting a continuous-time, continuously variable signal into a sampled and quantized signal. One such apparatus includes an input line for accepting an input signal that is continuous in time and continuously variable, multiple processing branches coupled to the input line, and an adder coupled to outputs of the processing branches. Each of the processing branches includes a continuous-time quantization-noise-shaping circuit, a sampling/quantization circuit coupled to an output of the continuous-time quantization-noise-shaping circuit, a digital bandpass filter coupled to an output of the sampling/quantization circuit, and a line coupling an output of the digital-to-analog converter circuit back into the continuous-time quantization-noise-shaping circuit. A center frequency of the digital bandpass filter in each the processing branch corresponds to a minimum in a quantization noise transfer function for the continuous-time quantization-noise-shaping circuit in the same processing branch.
Provided are, among other things, systems, methods and techniques for converting a continuous-time, continuously variable signal into a sampled and quantized signal. According to one representative embodiment, an apparatus includes multiple quantization-noise-shaping continuous-time filters, each in a separate processing branch and having an adder that includes multiple inputs and an output; an input signal is coupled to one of the inputs of the adder; the output of the adder is coupled to one of the inputs of the adder through a first filter; and the output of a sampling/quantization circuit in the same processing branch is coupled to one of the inputs of the adder through a second filter, with the second filter having a different transfer function than the first filter.
Provided are, among other things, systems, apparatuses methods and techniques for performing multi-bit quantization. One such apparatus includes an input signal line; a first comparator having a first input coupled to the input signal line, a second input coupled to a first reference signal, and an output; a rectifier having an input coupled to the input signal line and also having an output; and a second comparator having a first input coupled to the output of the rectifier, a second input coupled to a second reference signal, and an output, with the first comparator and the second comparator being clocked so as to produce sequences of quantized samples at substantially the same times.
Provided are, among other things, systems, methods and techniques for converting a continuous-time, continuously variable signal into a sampled and quantized signal. According to one implementation, an apparatus includes multiple processing branches, each including: a continuous-time quantization-noise-shaping circuit, a sampling/quantization circuit, and a digital bandpass filter. A combining circuit then combines signals at the processing branch outputs into a final output signal. The continuous-time quantization-noise-shaping circuits include adjustable circuit components for changing their quantization-noise frequency-response minimum, and the digital bandpass filters include adjustable parameters for changing their frequency passbands.
Provided are, among other things, systems, apparatuses, methods and techniques for converting a discrete-time quantized signal into a continuous-time, continuously variable signal. An exemplary converter preferably includes: (1) multiple oversampling converters, each processing a different frequency band, operated in parallel; (2) multirate (i.e., polyphase) delta-sigma modulators (preferably second-order or higher); (3) multi-bit quantizers; (4) multi-bit-to-variable-level signal converters, such as resistor ladder networks or current source networks; (5) adaptive non-linear, bit-mapping to compensate for mismatches in the multi-bit-to-variable-level signal converters (e.g., by mimicking such mismatches and then shifting the resulting noise to a frequently range where it will be filtered out by a corresponding bandpass (reconstruction) filter); (6) multi-band (e.g., programmable noise-transfer-function response) bandpass delta-sigma modulators; and/or (7) a digital pre-distortion linearizer (DPL) for canceling noise and distortion introduced by an analog signal bandpass (reconstruction) filter bank.
Provided are, among other things, systems, methods and techniques for converting a continuous-time, continuously variable signal into a sampled and quantized signal. According to one representative embodiment, an apparatus includes multiple continuous-time quantization-noise-shaping circuits, each in a separate processing branch and having an adder that includes multiple inputs and an output; an input signal is coupled to one of the inputs of the adder; the output of the adder is coupled to one of the inputs of the adder through a first filter; and the output of a sampling/quantization circuit in the same processing branch is coupled to one of the inputs of the adder through a second filter, with the second filter having a different transfer function than the first filter.
Provided are, among other things, systems, methods and techniques for converting a continuous-time, continuously variable signal into a sampled and quantized signal. According to one representative embodiment, an apparatus includes multiple quantization-noise-shaping continuous-time filters, each in a separate processing branch and having an adder that includes multiple inputs and an output; an input signal is coupled to one of the inputs of the adder; the output of the adder is coupled to one of the inputs of the adder through a first filter; and the output of a sampling/quantization circuit in the same processing branch is coupled to one of the inputs of the adder through a second filter, with the second filter having a different transfer function than the first filter.
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