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:
Feb. 11, 1997
Filed:
Sep. 27, 1995
Carmine J Pagano, Blairstown, NJ (US);
Jack C Wen, Parsippany, NJ (US);
Lucent Technologies Inc., Murray Hill, NJ (US);
Abstract
Disclosed is an apparatus for digitizing an electromagnetic input signal having frequency components within at least first and second segregated frequency bands, particularly useful in a wireless communications system. The apparatus includes a filtering circuit arrangement for passing only frequency components of the input signal substantially within the first and second frequency bands, to provide a filtered signal having a spectrum with spectral components below a predetermined power level within a frequency gap between the first and second frequency bands. An analog to digital (A/D) converter samples the filtered signal at a sampling rate sufficient to provide a digitized output signal with a frequency spectrum corresponding to that of the filtered signal and also with a replica of spectral components of one of the frequency bands appearing within the frequency gap. Preferably, the sampling rate used is less than the Nyquist sampling rate for the composite frequency band extending from the lowest to highest frequencies of the two bands. This allows a single A/D converter to be employed to sample the filtered signal, even when a large frequency gap exists between the segregated bands. A single mixer stage can then be used in conjunction with the single A/D converter in a wireless communications receiver application.