Antenna array for grating lobe and sidelobe suppression

Claim 2

A broadside antenna array comprising a plurality of module antennas arranged on centers in a plane, each of said modules having a radiation pattern directed substantially perpendicularly to the plane of the array, said array comprising a first module at a reference point, a first plurality of modules equally spaced apart in the amount of a first angle between modules at a first radial distance from said reference point, the first radial distance being slightly greater than the aperture dimension of said first module, one module of said first plurality being on a first radial line extending from said reference point, and a second plurality of modules equally spaced apart angularly at a second radial distance from said reference point about twice as great as said first radial distance, one module of said second plurality being on a second radial line extending from the reference point, said second radial line lying between said first line and a radial line bisecting said first angle to produce pseudo-random spacings between locations, as perpendicularly projected on a straight line in said plane, of the modules of both of said pluralities.

Claim 3

A broadside antenna array as defined in claim 1 wherein said second plurality comprises a number of modules less than twice said first plurality.

Claim 4

A broadside antenna array comprising a plurality of module antennas arranged on centers in a plane, each of said modules having a radiation pattern directed substantially perpendicularly to the plane of the array, said array comprising a first module having a center at a reference point, a first plurality of modules equally spaced apart in the amount of a first angle at a first radial distance from said reference point, the first radial distance being slightly greater than the aperture dimension of said first module, one module of said first plurality being on a first radial line extending from said reference point, a second plurality of modules comprising a greater number of modules than said first plurality and equally spaced apart angularly at a second radial distance from said reference point, one module of said second plurality being on a second radial line extending from the reference point, and a third plurality of modules equally spaced apart angularly at a third radial distance from said reference point about three times as great as said first radial distance, one module of said third plurality being on a third radial line extending from the reference point, said first, second, and third radial lines all having different directions from said reference point, said second radial line lying between said first line and a radial line bisecting said first angle to produce pseudo-random spacings between locations, as perpendicularly projected on a straight line in said plane, of the modules of all of said pluralities.

Claim 5

A broadside antenna array comprising a plurality of module antennas arranged on centers in a plane, each of said modules having a radiation pattern directed substantially perpendicularly to the plane of the array, said array comprising a first module having a center at a reference point, a first plurality of modules equally spaced apart in the amount of a first angle at a first radial distance from said reference point, the first radial distance being slightly greater than the aperture dimension of said first module, one module of said first plurality being on a first radial line extending from said reference point, a second plurality of modules comprising a greater number of modules than said first plurality and equally spaced apart angularly at a second radial distance from said reference point, one module of said second plurality being on a second radial line extending from the reference point, and a third plurality of modules equally spaced apart angularly at a third radial distance from said reference point about three times as great as said first radial distance, one module of said third plurality being on a third radial line extending from the reference point, said first, second, and third radial lines all having different directions from said reference point, said second radial line lying between said first line and a radial line bisecting said first angle to produce pseudo-random spacings between locations, as perpendicularly projected on a straight line in said plane, of the modules of all of said pluralities.

Claim 6

A broadside antenna array as defined in claim 3 and further comprising feed system means connected to said modules for receiving signals from said array in a receiving mode, corresponding by reciprocity to a transmitting mode in which said modules are excited with transmitting signals having predetermined relative amplitudes and having relative phases that are linearly related to a distance from said reference point to a point projected normally from each module onto a sTraight line in said plane extending through said reference point.

Claim 7

A broadside antenna array as defined in claim 3 and further comprising feed system means connected to said modules for exciting said modules in a transmitting mode with signals having predetermined relative amplitudes and having relative phases that are linearly related to a distance from said reference point to a point projected normally from each module onto a straight line in said plane extending through said reference point and for receiving signals from said array in a receiving mode, said receiving mode corresponding by reciprocity to said transmitting mode.

Claim 8

A broadside antenna array as defined in claim 3 wherein said third plurality comprises a number of modules less than three times the number of said first plurality.

Claim 9

An antenna array comprising a plurality of module antennas arranged on centers in a plane comprising a first module having a center at a reference point, a first plurality of modules equally spaced apart in the amount of a first angle at a first radial distance from said reference point, one module of said first plurality being on a first radial line extending from said reference point, a second plurality of modules comprising a greater number of modules than said first plurality and equally spaced apart angularly at a second radial distance from said reference point, one module of said second plurality being on a second radial line extending from the reference point, and a third plurality of modules equally spaced apart angularly at a third radial distance from said reference point about three times as great as said first radial distance, one module of said third plurality being on a third radial line extending from the reference point, said first, second, and third radial lines all having different directions from said reference point, said second radial line lying between said first line and a radial line bisecting said first angle to produce pseudo-random spacings between locations, as perpendicularly projected on a straight line in said plane, of the modules of all of said pluralities, and wherein said first plurality of modules comprises six modules spaced 60* apart, said second plurality comprises twelve modules spaced 30* apart, and said third plurality comprises twelve modules spaced 30* apart.

Claim 10

An antenna array comprising a plurality of module antennas arranged on centers in a plane comprising a first module having a center at a reference point, a first plurality of modules equally spaced apart in the amount of a first angle at a first radial distance from said reference point, one module of said first plurality being on a first radial line extending from said reference point, a second plurality of modules comprising a greater number of modules than said first plurality and equally spaced apart angularly at a second radial distance from said reference point, one module of said second plurality being on a second radial line extending from the reference point, and a third plurality of modules equally spaced apart angularly at a third radial distance from said reference point about three times as great as said first radial distance, one module of said third plurality being on a third radial line extending from the reference point, said first, second, and third radial lines all having different directions from said reference point, said second radial line lying between said first line and a radial line bisecting said first angle to produce pseudo-random spacings between locations, as perpendicularly projected on a straight line in said plane, of the modules of all of said pluralities, and wherein said first plurality of modules comprises six modules spaced 60* apart, said second plurality comprises twelve modules spaced 30* apart, and said third plurality comprises twelve modules spaced 30* apart.

Claim 11

An antenna array as defined in claim 7 and further comprising feed system means connected to said modules for exciting said modules with signals having predetermined relative amplitudes and having relative phases that are linearly related to a distance from said reference point to a point projected normally from each module onto a straight line in said plane extending through said reference point.

Claim 12

An antenna array as defined in claim 8 wherein said feed system means comprises means for exciting said modules with signals having unequal amplitudes.

Claim 13

An antenna array as defined in claim 7 wherein said second radial line extends in a direction about 7 1/2 * different from the direction of said first radial line, measured in a sense of rotation about said reference point, and said third radial line extends in a direction about 7 1/2 * different from the direction of said second radial line measured in the same sense of rotation about said reference point.

Claim 14

An antenna array as defined in claim 10 further comprising feed system means connected to said modules for exciting said modules with signals having predetermined relative amplitudes and having relative phases that are linearly related to a distance from said reference point to a point projected normally from each module onto a straight line in said plane extending through said reference point.

Claim 15

An antenna array comprising a plurality of module antennas arranged on centers in a plane comprising a first module at a reference point, a first plurality of modules equally spaced apart in the amount of a first angle between modules at a first radial distance from said reference point, one module of said first plurality being on a first radial line extending from said reference point, and a second plurality of modules equally spaced apart angularly at a second radial distance from said reference point about twice as great as said first radial distance, one module of said second plurality being on a second radial line extending from the reference point, said second radial line lying between said first line and a radial line bisecting said first angle to produce pseudo-random spacings between locations, as perpendicularly projected on a straight line in said plane, of the modules of both of said pluralities, and wherein said first plurality of modules comprises six modules spaced 60* apart, and said second plurality of modules comprises 12 modules spaced 30* apart.

Claim 16

An antenna array comprising a plurality of module antennas arranged on centers in a plane comprising a first module at a reference point, a first plurality of modules equally spaced apart in the amount of a first angle between modules at a first radial distance from said reference point, one module of said first plurality being on a first radial line extending from said reference point, and a second plurality of modules equally spaced apart angularly at a second radial distance from said reference point about twice as great as said first radial distance, one module of said second plurality being on a second radial line extending from the reference point, said second radial line lying between said first line and a radial line bisecting said first angle to produce pseudo-random spacings between locations, as perpendicularly projected on a straight line in said plane, of the modules of both of said pluralities, and wherein said first plurality of modules comprises six modules spaced 60* apart, and said second plurality of modules comprises 12 modules spaced 30* apart.

Claim 17

An antenna array comprising a plurality of module antennas arranged on centers in a plane comprising a first module at a reference point, a first plurality of modules equally spaced apart in the amount of a first angle between modules at a first radial distance from said reference point, one module of said first plurality being on a first radial line extending from said reference point, and a second plurality of modules equally spaced apart angularly at a second radial distance from said reference point about twice as great as said first radial distance, one module of said second plurality being on a second radial line extending from the reference point, said second radial line lying between said first line and a radial line bisecting said first angle to produce pseudo-random spacings between locations, as perpendicularly projected on a straight line in said plane, of the modules of both of said pluralities, and wherein said second radial line extends in a direction about 7 1/2 * different from the direction of said first radial line, measured rationally about said reference point.

Claim 18

An antenna array comprising a plurality of module antennas arranged on centers in a plane comprising a first module at a reference point, a first plurality of modules equally spaced apart in the amount of a first angle between modules at a first radial distance from said reference point, one module of said first plurality being on a first radial line extending from said reference point, and a second plurality of modules equally spaced apart angularly at a second radial distance from said reference point about twice as great as said first radial distance, one module of said second plurality being on a second radial line extending from the reference point, said second radial line lying between said first line and a radial line bisecting said first angle to produce pseudo-random spacings between locations, as perpendicularly projected on a straight line in said plane, of the modules of both of said pluralities, and wherein said second radial line extends in a direction about 7 1/2 * different from the direction of said first radial line, measured rationally about said reference point.