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:
Jun. 13, 2006
Filed:
Feb. 05, 2002
William Ellis Rodgers, Fort Wayne, IN (US);
Terrance Wayne Charbonneau, Fort Wayne, IN (US);
William Ellis Rodgers, Fort Wayne, IN (US);
Terrance Wayne Charbonneau, Fort Wayne, IN (US);
ITT Manufacturing Enterprises, Inc., Wilmington, DE (US);
Abstract
A technique for down converting signals from an Intermediate Frequency (IF) input signal to Inphase (I) and Quadrature (Q) signal samples at baseband replaces power-consuming A/D converters and AGC circuits with a low-cost zero-crossing comparator. The comparator converts the IF signal to a hard-limited signal having one value when the IF signal is positive and another value when the IF signal is negative. I and Q samples are generated by performing the equivalent of multiplication of the hard-limited signal by cos(2πfo*t) and sin(2πfo*t). By sampling the hard-limited signal at a rate that is an integer multiple of the intermediate frequency and an even number greater than or equal to four, multiplication by cos(2πf*t) and sin(2πf*t) required to generate I and Q baseband signal components is greatly reduced. The I and Q samples are summed (or integrated) by binary up/down counters over one bit duration and then dumped. The dumped counter outputs are estimates of the lowpass filtered I and Q signal components.