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:
Aug. 11, 2009
Filed:
Oct. 05, 2007
Brian P. Tremaine, San Jose, CA (US);
Brian P. Tremaine, San Jose, CA (US);
Other;
Abstract
Methods and apparatus for dither control of a micromirror using a servo control loop in an optical switching apparatus, an optical switching apparatus and optical network are disclosed. A servo control loop may use dither tone having two or more frequency components to dither an output driver that controls the position of a micromirror in an optical switch. The two components may be demodulated from an optical signal deflected by the micromirror. The optical signal may be fed into two band-pass filters. Each band-pass filter may have a pass band centered on a different one of the two frequency components. The envelope detector may compare the envelopes of the band-pass filter outputs. If the envelopes differ by more than a set threshold the output of the envelope detector may be forced to zero. Otherwise, the output of the envelope detector may be the sum of the two band-pass filter outputs.