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. 21, 1990
Filed:
Jun. 01, 1989
Jim P Lee, Nepean, CA;
Abstract
An interferometric acoustooptic signal processor utilizing a circular antenna array to cover a 360 degree field of view. Each antenna element of the array is connected to an input port of a Butler matrix. The signals are phase shifted within the Butler matrix and applied to a multi-channel periodic Bragg cell, resulting in generation of one or more acoustic waves therein. A laser beam is used to illuminate the Bragg cell and is modulated due to interaction with the acoustic waves, resulting in diffraction of the laser beam and generation of a diffracted beam pattern output from the Bragg cell. A Fourier transform lens focuses the diffracted laser beam on a back focal plane at a point characterized by two perpendicular coordinates designating the input signal power spectrum and the angle of incidence in relation to the antennae, respectively. By utilizing a circular antenna array with a Butler matrix a full 360 degree field of view is obtained using only one 2-D acoustooptic signal processor and the peak sidelobe to mainlobe level is reduced up to -30 dB. Furthermore, the accuracy and resolution of the processor are independent of frequency.