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. 11, 2002
Filed:
Nov. 30, 1998
James E. Leight, Los Angeles, CA (US);
TRW Inc., Redondo Beach, CA (US);
Abstract
An optically implemented wide bandwidth correlation system ( ) that employs a multi-mode imaging device ( ) and a particular modulation format to provide both in-phase and quadrature phase correlation components in a single correlation process. The correlation system ( ) includes an optical source ( ) that generates a laser beam ( ) that is split into a first beam path ( ) and a second beam path ( ). The first split beam and a first electrical signal are applied to a first modulator ( ) in the first path ( ) and the second split beam and the second electrical signal are applied to a second modulator ( ) in the second path ( ). The modulated beams are then applied to the optical imaging device ( ) that causes the beams to interfere with each other within an optical cavity ( ). Four optical outputs are connected to the optical cavity ( ) at strategic locations to provide a zero phase output and a &pgr; phase output that represent the in-phase correlation component, and a &pgr;/2 quadrature phase output and a 3&pgr;/2 quadrature phase output that represent the quadrature phase correlation component. A photodetector (60-66) detects each of the output signals from the imaging device ( ) to provide electrical signals indicative of the phase outputs. A first differential amplifier ( ) receives the electrical signals of the in-phase component and a second differential amplifier ( ) receives the electrical signals of the quadrature phase component. The differential amplifier outputs are applied to separate integrators ( ) to sum the signals for the correlation process. The modulators can be Mach-Zehnder interferometer modulators to provide a single sideband suppressed carrier modulation so that the in-phase and quadrature phase correlation components can be simultaneously generated.