Null steering antenna

Claim 2

In an antenna system of n antenna wherein a desired signal arrives in the general direction of main receiving beam and an undesired signal arrives in a direction at least slightly different from the direction of said desired signal; said main receiving beam having a main lobe in the direction of said desired signal and a minor lobe in the direction of said undesired signal, a method for generating a high quality beam in the direction of said desired signal and a null in the direction of said undesired signal comprising the steps of: calculating the progressive phase shift (φ) necessary to create a maximum in said main lobe; calculating the progressive phase shift (α) required to create a maximum in said minor lobe; determining the phase of said minor lobe relative to the voltage of said main beam; determining the amplitude of said minor lobe; calculating the ratio (k) of the amplitude of said minor lobe relative to the peak amplitude of said main beam; calculating the phase relationship (γ) between said minor lobe and said main beam at peak amplitude; calculating the value of 2 k sin [γ-n(φ-α)] for each of said n antennae; computing the arc tangent of each said value thereby determining the required phase shift for each antenna; and adding each said required phase shift to the corresponding antenna thereby establishing said null and said high quality beam.

Claim 3

In an antenna system of n antennae wherein a desired signal arrives in the general direction of a main receiving beam and an undesired signal arrives in a direction at least slightly different from the direction of said desired signal; said main receiving beam having a main lobe in the direction of said desired signal and a minor lobe in the direction of said undesired signal, a method for generating a high quality beam in the direction of said desired signal and a null in the direction of said undesired signal, comprising the steps of: calculating the progressive phase shift (φ) necessary to create a maximum in said main lobe; calculating the progressive phase shift (α) required to create a maximum in said minor lobe; determining the phase of said minor lobe, relative to the voltage of said main beam; determining the amplitude of said minor lobe; calculating the ratio (k) of the amplitude of said minor lobe relative to the peak amplitude of said main beam; calculating the phase relationship (γ) between said minor lobe and said main beam at peak amplitude; calculating the value of 2 k cos [γ-n(φ-α)] for each of n antennae thereby determining its required amplitude variation; and adding each said required amplitude variation to the corresponding antenna thereby establishing said null and said high quality beam.

Claim 4

In an antenna system of n antennae wherein a desired signal arrives in the general direction of a main receiving beam and an undesired signal arrives in a direction at least slightly different from the direction of said desired signal; said main receiving beam having a main lobe in the direction of said desired signal and a minor lobe in the direction of said undesired signal, a method for generating a high quality beam in the direction of said desired signal and a null in the direction of said undesired signal, comprising the steps of: calculating the progressive phase shift (φ) necessary to create a maximum in said main lobe; calculating the progressive phase shift (α) required to create a maximum in said minor lobe; determining the phase of said minor lobe, relative to the voltage of said main beam; determining the amplitude of said minor lobe; calculating the ratio (k) of the amplitude of said minor lobe relative to the peak amplitude of said main beam; calculating the phase relationship (γ) between said minor lobe and said main beam at peak amplitude; calculating the value of 2 k cos [γ-n(φ-α)] for each of n antennae thereby determining its required amplitude variation; and adding each said required amplitude variation to the corresponding antenna thereby establishing said null and said high quality beam.

Claim 5

In an antenna system of n antenna wherein a desired signal arrives in the general direction of a main beam and undesired signals arrive in a direction at least slightly different from the direction of said desired signal; said main beam having a main lobe in the direction of said desired signal and a minor lobe in the direction of each said undesired signal, a method for generating a high quality beam in the direction of said desired signal and a null in the direction of each undesired signal comprising the steps of: calculating the progressive phase shift (φ) necessary to create a maximum in said main lobe; calculating all progressive phase shifts (α) required to create a maximum in each minor lobe; determining the phase of each minor lobe relative to the voltage of said main beam; determining the amplitude of each minor lobe; calculating all ratios (k) of the amplitude of each minor lobe relative to the peak amplitude of said main beam; calculating all phase relationships (γ) between each minor lobe and said main beam at peak amplitude; for each null, repeatively follow the steps of calculating the value of 2 k sin [γ-n(φ-α)] for each of said antenna and with each calculation of said value taking into account the adjustments made in establishing any previous nulls; computing the arc tangent of each said value thereby determining the required phase shift for each antenna; and adding each required phase shift to the corresponding antenna thereby establishing a null in the direction of one of said undesired signals.

Claim 6

In an antenna system of n antenna wherein a desired signal arrives in the general direction of a main beam and undesired signals arrive in a direction at least slightly different from the direction of said desired signal; said main beam having a main lobe in the direction of said desired signal and a minor lobe in the direction of each said undesired signal, a method for generating a high quality beam in the direction of said desired signal and a null in the direction of each undesired signal comprising the steps of: calculating the progressive phase shift (φ) necessary to create a maximum in said main lobe; calculating all progressive phase shifts (α) required to create a maximum in each minor lobe; determining the phase of each minor lobe relative to the voltage of said main beam; determining the amplitude of each minor lobe; calculating all ratios (k) of the amplitude of each minor lobe relative to the peak amplitude of said main beam; calculating all phase relationships (γ) between each minor lobe and said main beam at peak amplitude; for each null, repeatively follow the steps of calculating the value of 2 k sin [γ-n(φ-α)] for each of said antenna and with each calculation of said value taking into account the adjustments made in establishing any previous nulls; computing the arc tangent of each said value thereby determining the required phase shift for each antenna; and adding each required phase shift to the corresponding antenna thereby establishing a null in the direction of one of said undesired signals.

Claim 7

In an antenna system of n antennae wherein a desired signal arrives in the general direction of a main beam and an undesired signal arrives in a direction at least slightly different from the direction of said desired signal; said main beam having a main lobe in the direction of said desired signal and a minor lobe in the direction of each said undesired signal, a method for generating a high quality beam in the direction of said desired signal and a null in the direction of each undesired signal comprising the steps of: calculating the progressive phase shift (φ) necessary to create a maximum in said main lobe; calculating all progressive phase shifts (α) required to create a maximum in each minor lobe; determining the phase of each minor lobe relative to the voltage of said main beam; determining the amplitude of each minor lobe; calculating all ratios (k) of the amplitude of each minor lobe relative to the peak amplitude of said main beam; calculating all phase relationships (γ) between each minor lobe and said main beam at peak amplitude; for each null, repetively follow the steps of calculating the value of 2 k cos [γ-n(φ-α)] for each of n antennae, with each value calculation taking into account the adjustments made in establishing any previous nulls; adding each said value calculated to the corresponding antenna thereby establishing a null in the direction of one of said undesired signals.

Claim 8

In an antenna system of n antennae wherein a desired signal arrives in the general direction of a main beam and an undesired signal arrives in a direction at least slightly different from the direction of said desired signal; said main beam having a main lobe in the direction of said desired signal and a minor lobe in the direction of each said undesired signal, a method for generating a high quality beam in the direction of said desired signal and a null in the direction of each undesired signal comprising the steps of: calculating the progressive phase shift (φ) necessary to create a maximum in said main lobe; calculating all progressive phase shifts (α) required to create a maximum in each minor lobe; determining the phase of each minor lobe relative to the voltage of said main beam; determining the amplitude of each minor lobe; calculating all ratios (k) of the amplitude of each minor lobe relative to the peak amplitude of said main beam; calculating all phase relationships (γ) between each minor lobe and said main beam at peak amplitude; for each null, repetively follow the steps of calculating the value of 2 k cos [γ-n(φ-α)] for each of n antennae, with each value calculation taking into account the adjustments made in establishing any previous nulls; adding each said value calculated to the corresponding antenna thereby establishing a null in the direction of one of said undesired signals.

Claim 9

The method of claim 1 wherein φ is calculated from the equation φ=d sin θ', d being the distance in radians between antennae, with θ' being the angle of arrival of the desired signal.

Claim 10

The method of claim 1 wherein α is calculated from the equation α=d sin θ*, d being the distance in radians between antennae, with θ* being the angle of arrival of the undesired signal.

Claim 11

The method of claim 2 wherein φ is calculated from the equation φ=d sin θ', d being the distance in radians between antennae, with θ' being the angle of arrival of the desired signal.

Claim 12

The method of claim 2 wherein α is calculated from the equation α=d sin θ*, d being the distance in radians between antennae, with θ* being the angle of arrival of the undesired signal.

Claim 13

The method of claim 3 wherein φ is calculated from the equation φ=d sin φ', d being the distance in radians between antennae, with θ' being the angle of arrival of the desired signal.

Claim 14

The method of claim 3 wherein α is calculated from the equation α=d sin θ*, d being the distance in radian between antennae, with θ* being the angle of arrival of the undesired signal.

Claim 15

The method of claim 4 wherein φ is calculated from the equation φ=d sin θ', d being the distance in radians between antennae, with θ' being the angle of arrival of the desired signal.

Claim 16

The method of claim 4 wherein α is calculated from the equation α=d sin θ*, d being the distance in radians between antennae, with θ* being the angle of arrival of the undesired signal.

Claim 17

A null steering antenna for creating a main receiving beam in the direction of a desired signal and a null in the direction of each undesired signal comprising: (a) an array of antennae positioned in the signal field; (b) null determining means for computing the phase shift value of the arc tangent of 2 k sin [γ-n(φ-α)] which is required to create each null; (c) adjustment means responsive to said null determining means for adjusting the phase of each antenna; (d) summing means to add the adjusted signals from said antennae; and (e) receiver means connected to the output of said summing means which thereby experiences a highly directional reception pattern that is receptive to signals arriving from the direction of said desired signal and virtually nonreceptive to signals arriving in the direction of said nulls.

Claim 18

A null steering antenna for creating a main receiving beam in the direction of a desired signal and a null in the direction of each undesired signal comprising: (a) an array of antennae positioned in the signal field; (b) null determining means for computing the phase shift value of the arc tangent of 2 k sin [γ-n(φ-α)] which is required to create each null; (c) adjustment means responsive to said null determining means for adjusting the phase of each antenna; (d) summing means to add the adjusted signals from said antennae; and (e) receiver means connected to the output of said summing means which thereby experiences a highly directional reception pattern that is receptive to signals arriving from the direction of said desired signal and virtually nonreceptive to signals arriving in the direction of said nulls.

Claim 19

The null steering antenna of claim 13 wherein said null determining means includes means for producing a primary antenna pattern in the direction of said desired signal, and secondary patterns superimposed on said primary pattern, the total number of secondary patterns corresponding to the number of nulls required.

Claim 20

The null steering antenna of claim 14 wherein each secondary pattern has one or more pairs of components, one component of each pair being on each side of said main receiving beam, the component of each pair on the side closest to said undesired signal having magnitude and phase chosen to combine with said primary pattern and any previous superimposed pattern to nullify said undesired signal, the component of each pair distant from said undesired signal having magnitude and phase chosen to eliminate the amplitude variations between antenna outputs.

Claim 21

A null steering antenna for creating a main receiving beam in the direction of a desired signal and a null in the direction of each undesired signal comprising (a) an array of antennae positioned in the signal field; (b) null determining means for computing the amplitude variation value of 2 k cos [γ-n(φ-α)] which is required to create each null; (c) adjustment means responsive to said null determining means for adjusting the amplitude of each antenna; (d) summing means to add the adjusted signals from said antennae; and (e) receiver means connected to the output of said summing means which thereby experiences a highly directional reception pattern that is receptive to signals arriving from the direction of said desired signal and virtually non-receptive to signals arriving in the direction of said nulls.

Claim 22

A null steering antenna for creating a main receiving beam in the direction of a desired signal and a null in the direction of each undesired signal comprising (a) an array of antennae positioned in the signal field; (b) null determining means for computing the amplitude variation value of 2 k cos [γ-n(φ-α)] which is required to create each null; (c) adjustment means responsive to said null determining means for adjusting the amplitude of each antenna; (d) summing means to add the adjusted signals from said antennae; and (e) receiver means connected to the output of said summing means which thereby experiences a highly directional reception pattern that is receptive to signals arriving from the direction of said desired signal and virtually non-receptive to signals arriving in the direction of said nulls.

Claim 23

The null steering antenna of claim 16 wherein said null determining means includes means for producing a primary antenna pattern in the direction of said desired signal and secondary antenna patterns superimposed on said primary pattern, the total number of secondary patterns corresponding to the number of nulls required.

Claim 24

The null steering antenna of claim 17 wherein each secondary pattern has one or more pairs of components, one component of each pair being on each side of said main receiving beam, the component of each pair on the side closest to said undesired signal having magnitude and phase chosen to combine with said primary pattern and any previous superimposed pattern to nullify said undesired signal, the component of each pair distant from said undesired signal having magnitude and phase chosen to eliminate the phase variation between antenna outputs.

Claim 25

The null steering of claim 14 wherein said means for producing said primary antenna pattern includes means for determining the progressive phase shift required to create a beam maximum in the desired signal direction.

Claim 26

The null steering antenna of claim 17 wherein said means for producing said primary antenna pattern includes means for determining the progressive phase shift required to create a beam maximum in the desired signal direction.