US 4,879,488 A · Vernier for superconducting analog-to-digital converter

Abstract

An analog-to-digital converter employing superconducting quantum interference devices (SQUID's) to produce countable voltage pulses at uniformly spaced quantization levels, the converter having multiple SQUID quantizers, each of which receives an identical analog signal current to be converter to digital form, and a bias current to provide an offset in the position of the quantization level for each quantizer. For a quantization current of .DELTA.i, the bias currents in each of 2.sup.n quantizers are 0, .DELTA.i/2.sup.n, 2.DELTA.i/2.sup.n, and so forth up to (2.sup.n -).DELTA.i/2.sup.n. The outputs of the quantizers are monitored in associated flip-flop circuits, the states of which are sampled and decoded to yield an n-bit output that can be combined with the output of a binary counter monitoring just one of the quantizers. The quantizers provide outputs that are effectively interleaved between adjacent quantization levels of a single quantizer. This arrangement of multiple quantizers can be employed to increase the sampling rate or the resolution of the converter, without needing any improvement in the basic response time of the quantizers.

Claims14

Dependent claims

A superconducting analog-to-digital converter, comprising:

a plurality of quantizers in the form of superconducting quantum interference devices (SQUID's), configured to generate voltage pulses at periodically spaced quantization levels of analog signal current applied to the quantizers;
means for applying an approximately identical analog signal current to each of the plurality of quantizers;
means for applying a different bias current to each of the plurality of quantizers, such that the quantization levels are offset from each other in a uniform manner to provide for interpolation between adjacent quantization levels of a single quantizer, wherein the differently biased quantizers provide a set of quantization levels interleaved between any two adjacent quantization levels of a single quantizer;
and
means for monitoring the voltage pulses output by the quantizers to determine the digital equivalents of changes in the analog signal current.

2 more elements

A superconducting analog-to-digital converter, comprising:

a plurality of (2.sup.n) of quantizers in the form of superconducting quantum interference devices (SQUID's), where n is a positive integer, configured to generate voltage pulses at periodically spaced quantization levels of an analog signal current applied to the quantizers, adjacent current quantization levels being separated by a uniform current quantum of .DELTA.i, where .DELTA.i is the change in analog signal current between adjacent quantization levels associated with any one of the quantizers;
means for supplying substantially equal analog signal currents to the plurality of quantizers;
means for applying a different bias current to each of the plurality of quantizers, such that the quantization levels are offset from each other in a uniform manner to provide for interpolation between adjacent quantization levels of a single quantizer, the quantizer bias currents having respective values of 0, .DELTA.i/2.sup.n, 2.DELTA.i/2.sup.n, and so forth up to (2.sup.n-1).DELTA.i/2.sup.n ;
and
means for monitoring the voltage pulses output by the quantizers to determine the digital equivalents of changes in the analog signal current, to obtain a set of quantization levels interleaved between normally spaced quantization levels thereby permitting increased resolution or an increased sampling rate from the converter.

2 more elements

Dependencies are inferred from the claim text.

Vernier for superconducting analog-to-digital converter

Life of this patent

Vernier for superconducting analog-to-digital converter

Life of this patent

Abstract

Claims14