Accession Number : ADD001885
Title : Radio-Frequency Holography.
Descriptive Note : Patent,
Corporate Author : DEPARTMENT OF THE NAVY WASHINGTON D C
Personal Author(s) : Hendrix,Charles E
Report Date : 03 Jun 1975
Pagination or Media Count : 5
Abstract : The patent relates to a passive radio direction finder which monitors wavefronts across an aperture, produces a radio-frequency hologram, and numerically reconstructs the hologram. The direction finder consists of an array of antennas to sample the phase of incoming wavefronts, a plurality of mixers separately connected to individual antennas, a phase lock loop or bandpass limiter connected between any individual antenna and an input of each mixer to provide a mixer reference signal, a multichannel analog to digital converter attached to the output of each mixer, and a digital computer programmed to make fast Fourier transform calculations. In lieu of the plurality of antennas and mixers, a moving probe antenna and single mixer may be used if a sample and hold circuit is added to the phase lock circuit to provide a reference signal.
Descriptors : *Radio direction finders, *Direction finding, *Patents, Passive systems, Radiofrequency, Phase measurement, Phase locked systems, Fourier transformation, Analog to digital converters, Signal processing, Angle of arrival, Holography
Subject Categories : Direction Finding
Distribution Statement : APPROVED FOR PUBLIC RELEASE