The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Mar. 23, 1993
Filed:
Feb. 21, 1992
Ian A Galton, Pasadena, CA (US);
California Institute of Technology, Pasadena, CA (US);
Abstract
An approach is presented for relaxing the oversampling requirements in a .DELTA..SIGMA. modulator based analog-to-digital converter through parallel .DELTA..SIGMA. modulation channels with decimation filtering and modulation by sequences u.sub.r (n) and v.sub.r (n) derived, for example, from an M.times.M Hadamard matrix. By combining M .DELTA..SIGMA. modulators, each with an oversampling ratio of N, an effective oversampling ratio of approximately NM is achieved with only an M-fold increase in the quantization noise power. In the special case of N=1, full-rate analog-to-digital conversion is achieved. The individual .DELTA..SIGMA. modulators can be any selected from a large class of popular .DELTA..SIGMA. modulators. Unlike most other approaches to trading modulator complexity for accuracy, the system retains the robustness of the individual .DELTA..SIGMA. modulators to circuit imperfections.