Method and apparatus for four-beam radar
First Claim
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1. A four-beam radar apparatus comprising:
- means for generating a driving signal;
means connected to said generating means, for splitting said driving signal into 4n2 driving signals where n is a nonzero positive integer;
4n2 phase shifters divided in a predetermined fashion into n2 phasing groups of four phase shifters apiece for generating predetermined phase shifts;
4n2 array elements arranged in a 2n×
2n square matrix divided in a predetermined fashion into n2 element groups of four array elements apiece;
n2 switching means respectively associated with one of said n2 phasing groups and one of said n2 element groups for selectably and alternately interconnecting said four elements in said element group and said four phase shifters in said phasing group in one of four alternate predetermined interconnections;
said 4n2 array elements being arranged at positions (±
j, ±
k) where j and k are positive integers between one and n inclusively;
each ordered coordinate pair j, k determining one of said n2 element groups; and
each ordered pair j, k determining one of said phasing groups, the four phase shifts being created by said group being determined by the product of a unit phase shift times ±
x or ±
y, where x equals (j+k-1), and where y equals (j-k).
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Abstract
A method and apparatus for producing remote profiling beams pointing altetely to the north, east, west or south by ordered distribution of phase shifts to elements of a square antenna array. Elements within a given group of four array elements share a related group of four phase shift means. Elements in a group trade phase shift means intragroup but there is no intergroup trading. The arrangement permits four-beam capability without unduly increasing the cost or complexity of the radar assembly over prior art assemblies. Also disclosed is a system for "tipping" the array either virtually or physically to obtain a vertical beam.
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Citations
3 Claims
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1. A four-beam radar apparatus comprising:
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means for generating a driving signal; means connected to said generating means, for splitting said driving signal into 4n2 driving signals where n is a nonzero positive integer; 4n2 phase shifters divided in a predetermined fashion into n2 phasing groups of four phase shifters apiece for generating predetermined phase shifts; 4n2 array elements arranged in a 2n×
2n square matrix divided in a predetermined fashion into n2 element groups of four array elements apiece;n2 switching means respectively associated with one of said n2 phasing groups and one of said n2 element groups for selectably and alternately interconnecting said four elements in said element group and said four phase shifters in said phasing group in one of four alternate predetermined interconnections; said 4n2 array elements being arranged at positions (±
j, ±
k) where j and k are positive integers between one and n inclusively;each ordered coordinate pair j, k determining one of said n2 element groups; and each ordered pair j, k determining one of said phasing groups, the four phase shifts being created by said group being determined by the product of a unit phase shift times ±
x or ±
y, where x equals (j+k-1), and where y equals (j-k). - View Dependent Claims (2, 3)
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Specification