Accession Number : ADD018267
Title : Direction Finding Apparatus Using Tunable Fiber Optic Delay Line.
Descriptive Note : Patent, Filed 23 Feb 95, patented 25 Jun 96,
Corporate Author : DEPARTMENT OF THE NAVY WASHINGTON DC
Personal Author(s) : Rast, Howard E
Report Date : 25 Jun 1996
Pagination or Media Count : 8
Abstract : A direction finding apparatus and method for an RF signal are described which provide a variable time delay in fiber optic cables. A tunable transmitter launches optical emissions of several wavelengths into a plurality of fiber optic cables. Since the waveguide material of each cable exhibits anomalous dispersion of the optical emissions, large changes in group refractive index are provided as a function of the different wavelengths of the optical emissions. As a consequence, only small changes in the different wavelengths of the optical emissions produce large changes in the time delay of the different wavelengths of the optical emissions within a fixed length of the optical fiber cables. This apparatus and method produce sensitive angle of arrival determinations for RF signals.
Descriptors : *DIRECTION FINDING, *RADIO DIRECTION FINDERS, *PATENTS, ANOMALIES, TIME INTERVALS, REFRACTIVE INDEX, SENSITIVITY, FIBER OPTICS TRANSMISSION LINES, TUNING, DELAY LINES, RADIOFREQUENCY PULSES
Subject Categories : Direction Finding
Distribution Statement : APPROVED FOR PUBLIC RELEASE