An apparatus for converting a continuous-time, continuously variable signal into a sampled and quantized signal, comprising: an input line for accepting the continuous-time, continuously variable signal a plurality of processing branches (110, 120) coupled to the input line, each of said processing branches including: (a) a quantization-noise-shaping continuous-time filter (113, 123), (b) a sampling/quantization circuit coupled to an output of the quantization noise-shaping continuous-time filter (113, 123), (c) a digital bandpass filter (115, 125) coupled to an output of the sampling/quantization circuit (113, 123), and (d) a line coupling the output of the sampling/quantization circuit back into the quantization-noise-shaping continuous-time filter (113, 123); and an output adder having inputs coupled to outputs of the plurality of processing branches and an output that provides said sampled and quantized signal, wherein each of said quantization-noise-shaping continuous-time filters (113, 123) comprises an internal adder that includes a plurality of inputs and an output, with the continuous-time, continuously variable signal being coupled to one of the inputs of the internal adder, the output of the internal adder being coupled to one of the inputs of the internal adder through a first continuous-time filter (154A&C), and the output of the sampling/quantization circuit in the same processing branch being coupled to one of the inputs of the internal adder through a second continuous-time filter (154B&C), and the second continuous-time filter having a different transfer function than the first continuous-time filter, the overall responses of the first continuous-time filter (154A&C) and/or the second continuous-time filter (154B&C) include a lowpass filtering with a bandwidth that is no greater than the sampling rate of said sampling/quantization circuit, the quantization-noise-shaping continuous-time filters (113, 123) in different ones of the plurality of processing branches (110, 120) have quantization noise minima at different frequencies, and the quantization noise minimum for each of the quantization-noise-shaping continuous-time filters (113, 123) corresponds to a frequency band selected by the digital bandpass filter (115, 125) in the same processing branch (110, 120). an input line for accepting the continuous-time, continuously variable signal a plurality of processing branches (110, 120) coupled to the input line, each of said processing branches including: (a) a quantization-noise-shaping continuous-time filter (113, 123), (b) a sampling/quantization circuit coupled to an output of the quantization noise-shaping continuous-time filter (113, 123), (c) a digital bandpass filter (115, 125) coupled to an output of the sampling/quantization circuit (113, 123), and (d) a line coupling the output of the sampling/quantization circuit back into the quantization-noise-shaping continuous-time filter (113, 123); and an output adder having inputs coupled to outputs of the plurality of processing branches and an output that provides said sampled and quantized signal, wherein each of said quantization-noise-shaping continuous-time filters (113, 123) comprises an internal adder that includes a plurality of inputs and an output, with the continuous-time, continuously variable signal being coupled to one of the inputs of the internal adder, the output of the internal adder being coupled to one of the inputs of the internal adder through a first continuous-time filter (154A&C), and the output of the sampling/quantization circuit in the same processing branch being coupled to one of the inputs of the internal adder through a second continuous-time filter (154B&C), and the second continuous-time filter having a different transfer function than the first continuous-time filter, the overall responses of the first continuous-time filter (154A&C) and/or the second continuous-time filter (154B&C) include a lowpass filtering with a bandwidth that is no greater than the sampling rate of said sampling/quantization circuit, the quantization-noise-shaping continuous-time filters (113, 123) in different ones of the plurality of processing branches (110, 120) have quantization noise minima at different frequencies, and the quantization noise minimum for each of the quantization-noise-shaping continuous-time filters (113, 123) corresponds to a frequency band selected by the digital bandpass filter (115, 125) in the same processing branch (110, 120).