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. 09, 1999
Filed:
Mar. 17, 1998
William Edward Jacklin, Lombard, IL (US);
Other;
Abstract
A method and a coarse tuning circuit for performing direct frequency selection and down-conversion on a received analog bandpass signal for a digital receiver having C channels are disclosed. Each of the C channels has a bandwidth B. The analog bandpass signal in a channel of interest has a center frequency f.sub.c and a two-sided bandwidth not greater than B. The method comprises the following steps: (a) sampling the bandpass signal at a sampling frequency f.sub.s greater than twice the product of B and C, to produce a digital sampled signal which has an intermediate frequency much closer to the baseband frequency of zero kilohertz than the sampling frequency f.sub.s ; (b) computing, from f.sub.c and f.sub.s, a non-negative integer value m to determine the selection of a channel from the C channels of the digital receiver; and (c) forming directly from the digital sampled signal two digital signals I.sub.1 and Q.sub.1 such that they correspond to a digital in-phase component and a quadrature component, respectively, of a complex signal which is approximately centered at a frequency .DELTA.f proximate of the baseband frequency, and which has a frequency spectrum approximately equal to that of the analog bandpass signal.