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. 12, 1991
Filed:
Jan. 09, 1989
Donald W Tufts, East Greenwich, RI (US);
Abstract
Apparatus for producing the Fourier coefficients of a time and/or space-varying input signal utilizes a bank of delay filters whose outputs are selectively connected to the inputs of a bank of accumulating circuit each of which produces one of the desired Fourier coefficients. Each of the delay filters produces an output signal which is the weighted average of one or more samples of the input signal, the samples being equally spaced in time over the period of the input signal. The accumulating circuits, equal in number to the number of harmonics in the desired Fourier series, each produce a weighted sum of the output(s) of selected delay filters which are interconnected with the accumulating circuits in accordance with the so-called Mobius function. The apparatus may employ either general purpose or special purpose digital or analog processing circuits, and is particularly suitable for implementation with VLSI fabrication techniques. Futher circuit simplification may be achieved by preprocessing the input signal into a delta modulated bipolar signal to reduce the number of internal data paths and to permit the signal averaging function to be implemented with a simple up-down counter.