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. 10, 2004
Filed:
Dec. 21, 2001
Frederick J. Martin, Plantation, FL (US);
Motorola, Inc., Schaumburg, IL (US);
Abstract
A digital IF to base band demodulator ( ) includes delta sigma samplers ( ) for sampling two channels of an IF signal at a sampling rate that is substantially higher than the Nyquist rate for the IF signal. A first pair of decimation filters ( ) decimates and filters the output of the delta sigma samplers ( ) but keeps the samples at a rate sufficient to perform digital mixing, cross adding, and pulse shape match filtering. A set of mixers ( ) mixers the output of the first pair of decimation filters with two phases of a digital representation of an local IF signal. A pair of summers ( ) sums, and subtracts outputs of the set of mixers ( ) in order to cancel undesired harmonics. A second set of decimation filters ( ) decimates and filters the output of the summers ( ) applying a filter function that is matched to a pulse shape of a base band signal present in the IF signal.