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:
Oct. 24, 1989
Filed:
Mar. 07, 1988
Michael S Masheff, St. Petersburg, FL (US);
E-Systems, Inc., Dallas, TX (US);
Abstract
A discrete fourier transform direction finding apparatus for performing a direction finding function on signals received through two antennae separated by a known distance. The outputs of the respective antennae are connected to first and second receiver channels which convert the received signals down to baseband and provide orthogonal I and Q channel outputs. A common local oscillator is used to maintain phase coherency between the channels and AGC signals are provided to maintain identical delays in the receiver RF paths. The processed signals from each receiver channel are than fed into a respective charge coupled device Chirp-Z transform (discrete fourier transform) circuit to produce real and imaginary components of the received signals. These signals are then converted to digital form and are used by subsequent circuitry to determine the angle of arrival of the received signal.