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. 25, 1980
Filed:
Feb. 03, 1975
Frederick C Alpers, Riverside, CA (US);
The United States of America as represented by the Secretary of the Navy, Washington, DC (US);
Abstract
A passive direction finding system incorporating at least one set of spacapart antennas, the incoming signal at one antenna being coupled through a delay line having a multiplicity of taps thereon, a plurality of channels equal in number to the number of delay taps and signal processing means coupled to the output of said channels, a reference channel coupled to the output of the other antenna, phase shifting means for varying the phase of the reference channel signal, a frequency modulated oscillator which provides an output signal that is beat against the outputs of the delay line and the output of the second antenna, and a correlator coupled to the output of the channels for determining when correlation exists between a signal from the first antenna and the second antenna to indicate direction of an incoming signal with respect to the baseline between the set of antennas.