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:
Nov. 04, 2003
Filed:
Mar. 16, 2001
Shane J. Strutz, Columbia, MD (US);
Keith J. Williams, Dunkirk, MD (US);
The United States of America as represented by the Secretary of the Navy, Washington, DC (US);
Abstract
An optical image reject down-converter for mapping a received radio frequency (RF) into an arbitrary intermediate frequency range and for precluding interference between the received signals. A received radio frequency signal is down-converted into an intermediate frequency band for use by an electronic circuit in other devices. Optical light is divided into a first path and a second path. Light in the first path is transferred into an optical sideband by a first optical modulator or phase modulator. Light in a second path is converted into sidebands by a second, non-cascaded optical modulator and then passed through a tunable narrow-band optical filter which selects the desired sideband. The optical spectrum of the second path then primarily includes light at the frequency equal to the original laser frequency plus the additional sidebands. The filtered sideband is heterodyned with the light from the first path, resulting in a down-conversion to the desired intermediate frequency. Image frequencies initially present in the optical link are thereby filtered and rejected.