Sampling/quantization converters
AssigneeSyntropy Systems, LLC
InventorChristopher Pagnanelli
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Abstract
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.
Claims27
-39. (canceled)
An apparatus for converting a continuous-time, continuously variable signal into a sampled and quantized signal, comprising:
- an input line for accepting an input signal that is continuous in time and continuously variable;
- a plurality of processing branches coupled to the input line, each of said processing branches including:
- (a) a continuous-time quantization-noise-shaping circuit, (b) a sampling/quantization circuit coupled to an output of the continuous-time quantization-noise-shaping circuit, (c) a digital bandpass filter coupled to an output of the sampling/quantization circuit, and (d) a line coupling the output of the sampling/quantization circuit back into the continuous-time quantization-noise-shaping circuit;
- and
- an adder coupled to outputs of the plurality of processing branches,
- wherein a center frequency of the digital bandpass filter in each said processing branch corresponds to a minimum in the quantization noise transfer function for the continuous-time quantization-noise-shaping circuit in the same processing branch, and
- wherein each of said digital bandpass filters includes:
- (a) a quadrature frequency downconverter that generates in-phase and quadrature outputs, using cosine and sine sequences with a frequency corresponding to the minimum in the quantization noise transfer function, (b) a first moving-average filter coupled to the in-phase output of the quadrature frequency downconverter, (c) a second moving-average filter coupled to the quadrature output of the quadrature frequency downconverter, and (d) a quadrature frequency upconverter that uses cosine and sine sequences with the frequency corresponding to the minimum in the quantization noise transfer function.
An apparatus for converting a continuous-time, continuously variable signal into a sampled and quantized signal, comprising:
- an input line for accepting an input signal that is continuous in time and continuously variable;
- a continuous-time quantization-noise-shaping filter;
- and
- a sampling/quantization circuit coupled to an output of the continuous-time quantization noise-shaping filter,
- wherein the continuous-time quantization-noise-shaping filter comprises an adder that includes a plurality of inputs and an output, with the input signal being coupled to one of the inputs of the adder, the output of the adder being coupled to one of the inputs of the adder through a first filter, the output of the sampling/quantization circuit in the same processing branch being coupled to one of the inputs of the adder through a second filter, and the second filter having a different transfer function than the first filter, and
- wherein the continuous-time quantization-noise-shaping filter has a noise transfer function with a minimum at a particular frequency.
Dependencies are inferred from the claim text.