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. 16, 2000
Filed:
Aug. 11, 1998
Richard A Fields, Redondo Beach, CA (US);
David L Rollins, Hawthorne, CA (US);
Stephen R Perkins, Redondo Beach, CA (US);
Eric L Upton, Redondo Beach, CA (US);
Elizabeth T Kunkee, Manhattan Beach, CA (US);
Lawrence J Lembo, Torrance, CA (US);
Juan C Carillo, Jr, Torrance, CA (US);
Mark Kintis, Manhattan Beach, CA (US);
TRW Inc., Redondo Beach, CA (US);
Abstract
A frequency modulation-based optical analog-to-digital converter utilizes a downward-folding, successive approximation approach. A series of stages is utilized to generate bits in the digital signal. In each stage, complementary low and high bandpass filters collectively cover a bandpass frequency range from a low frequency to a high frequency. The high frequency filtered signal from the high bandpass filter is observed to obtain a bit in the digital word. By performing the folding operations in the frequency domain, the converter avoids the difficult task of optical power subtraction, relying instead on frequency down-conversions. The high frequency filtered signal passed by the high bandpass filter is then downconverted and added to the low pass filter signal to generate a modulated signal for the next stage.