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:
Nov. 25, 1997
Filed:
Jul. 28, 1995
Zbigniew Czyzewski, Knoxville, TN (US);
Ronald G Canada, Knoxville, TN (US);
Computational Systems, Inc., Knoxville, TN (US);
Abstract
A zoom processor for increasing the resolution of a band of interest within an acquired analog time domain frequency signal. The signal is converted from an analog time domain signal to a digital time domain signal. Next, the signal is multiplied by a value which will lower the center frequency of the band of interest to zero. The value by which the signal is multiplied is based on both the sine and cosine of a function of the center frequency and the sampling frequency used to digitize the signal. The sine function is solved with the aid of a numerical substitution which simplifies finding the value of the function in a sine table. After the signal is shifted, it is low-pass filtered, which removes all of the signal except the band of interest. During filtering, the band is also decimated by a predetermined factor, which compresses the time domain signal, and proportionally expands the frequency domain signal which is produced at a later step of the method. A transform, such as a Fast Fourier Transform, is performed on the band, to convert the signal from time domain to frequency domain. The signal is analyzed according to the ultimate function of the instrument in which the zoom processor is incorporated.