Patent ID: 6195043
Filing Date: 2001-02-27
Classification: G01S,H01Q

Abstract:
An improved apparatus for determining the angles-of-arrival and polarization states of a plurality of incoming electromagnetic waves, said apparatus of the type having means for determining the frequencies of said plurality of incoming electromagnetic waves, wherein the improvement comprises:(a) an antenna array comprising at least six sensing elements of differing and substantially known orientations of the polarization for converting said plurality of incoming electromagnetic waves into voltages; said elements being distributed about a principal axis where said distribution has a geometric center coinciding with the principal axis; each of said elements possessing a tilted polarization orientation characterized by a tilt angle with respect to said principal axis where the polarization orientation of each sensing element is tilted an equivalent angle; said polarization orientation capable of assuming values between zero and 2.pi., inclusive, excepting polarization orientations that are substantially radial from the geometric center of said antenna array;(b) an element selection network for electrically and switchably conducting said plurality of incoming electromagnetic waves as voltages to a receiver comprising at least five channels for receiving said plurality of incoming electromagnetic waves as voltages; said antenna element selection network providing at least five output signals;(c) measuring means for determining signal power of said voltages of said plurality of incoming electromagnetic waves as produced by said receiver;(d) a plurality of differencing junctions for determining phase differences of the plurality of incoming electromagnetic waves as produced by said receiver;(e) processing means for determining phase corrections to said phase differences of said plurality of incoming electromagnetic waves from said signal power of said voltages;(f) at least one summing junction for correcting said phase differences with said phase corrections; and(g) processing means for resolving angular ambiguities with said plurality of incoming electromagnetic waves and the corrected phase difference;whereby said angles-of-arrival and polarization of incoming electromagnetic waves are determined.