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:
Aug. 22, 2006
Filed:
Nov. 24, 1999
Hanna S-h. Hsu, Cerritos, CA (US);
Maneesh Goyal, Hermosa Beach, CA (US);
Jeffrey B. Warner, Hermosa Beach, CA (US);
Ronald P. Smith, Redondo Beach, CA (US);
Hanna S-H. Hsu, Cerritos, CA (US);
Maneesh Goyal, Hermosa Beach, CA (US);
Jeffrey B. Warner, Hermosa Beach, CA (US);
Ronald P. Smith, Redondo Beach, CA (US);
Northrop Grumman Corporation, Los Angeles, CA (US);
Abstract
A discrete Fourier transform (DFT) filter bank with stack shift capability, configured, for example, as an analyzer, but equally applicable to a synthesizer, and implemented as a polyphase filter. The DFT filter bank includes a complex modulator for multiplying the input signals x(m), x(m) . . . x(m) by a complex modulator e(m). In order to keep the coefficients for the polyphase filter real, the coefficients are modulated by a DFT twiddle factor e. The use of the DFT twiddle factor enables the hardware to be reduced significantly. For example, for an 8 phasetap filter, only 8 selectable negators are required as opposed tofor known DFT filter banks.