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:
May. 10, 2016
Filed:
Oct. 01, 2012
Applicant:
Creative Technology Ltd, Singapore, SG;
Inventor:
David Philip Rossum, Santa Cruz, CA (US);
Assignee:
Creative Technology Ltd, Singapore, SG;
Attorneys:
Primary Examiner:
Int. Cl.
CPC ...
H04B 15/00 (2006.01); H03H 17/02 (2006.01); H03H 17/04 (2006.01);
U.S. Cl.
CPC ...
H03H 17/0288 (2013.01); H03H 17/045 (2013.01); H03H 17/0233 (2013.01); H03H 2017/0247 (2013.01); H03H 2017/0472 (2013.01);
Abstract
A new and more efficient filtering system (e.g., digital microphone decimation filter architecture system) is described. A key to this architecture is the use of two parallel filter paths. Each path operates at the output sample rate, and comprises a shorter FIR filter followed by a series of allpass stages (e.g., implementing IIR filters). The FIR filter is designed to remove all but the last octave of out-of-band noise. The allpass stages are designed such that when the two paths are summed together, the out-of-band noise for the final octave cancels out, leaving only the desired sign.