Beam scanning antennas with plurality of antenna elements for scanning beam direction
First Claim
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1. An array antenna comprising:
- a circular antenna array constructed of a number i of antenna elements disposed on a periphery of a circle at respective position angles ψ
i relative to a radial axis of the circle; and
phase shifting means for giving a respective phase shift α
i to radiation directivity of each of said antenna elements and for making the phase shift α
i equal to n times the position angle ψ
i, n being an integer excluding 0, wherein said phase shifting means comprises a rotating antenna element and said rotating antenna element comprises said antenna elements, each of which rotates for an angle α
i.
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Abstract
An array antenna is formed of a plurality of antenna elements, each of which scans a beam in the direction of an angle θ to a boresight of the antenna and electrically varies the direction of a rotation angle φ of the beam. The antenna elements are disposed so that the optical path difference of radio waves transmitted or received by two adjacent antenna elements in the directions of a plurality of direction angles φ on the plane tilted for an angle θ to the boresight of the antenna is nearly a multiple of the wave length of the radio waves.
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Citations
11 Claims
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1. An array antenna comprising:
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a circular antenna array constructed of a number i of antenna elements disposed on a periphery of a circle at respective position angles ψ
i relative to a radial axis of the circle; and
phase shifting means for giving a respective phase shift α
i to radiation directivity of each of said antenna elements and for making the phase shift α
i equal to n times the position angle ψ
i, n being an integer excluding 0,wherein said phase shifting means comprises a rotating antenna element and said rotating antenna element comprises said antenna elements, each of which rotates for an angle α
i.- View Dependent Claims (2)
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3. An array antenna comprising:
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number k of circular antenna arrays constructed of a number of i of antenna elements disposed on any periphery of concentric circles having radii different from each other and disposed at respective position angles ψ
k−
i relative to a radial axis of the circle; and
phase shifting means for giving a phase shift α
k−
i to radiation directivity of each of said antenna elements disposed on the same periphery and for making the phase shift α
k−
i equal to nk times position angle ψ
k−
i, nk being an integer excluding 0,wherein said integers nk are different from each other. - View Dependent Claims (4)
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5. An array antenna comprising:
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number k of circular antenna arrays constructed of a number of i of antenna elements disposed on any periphery of concentric circles having radii different from each other and disposed at respective position angles ψ
k−
i relative to a radial axis of the circle; and
phase shifting means for giving a phase shift α
k−
i to radiation directivity of each of said antenna elements disposed on the same periphery and for making the phase shift α
k−
i equal to nk times position angle ψ
k−
i, nk being an integer excluding 0,wherein the array antenna further comprises an RF switch for selecting a circular antenna array.
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6. An array antenna comprising:
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number k of circular antenna arrays, constructed of a number i of antenna elements disposed on any periphery of concentric circles having radii different from each other and disposed at respective position angles ψ
k−
i relative to a radial axis of the circle; and
phase shifting means for giving a phase shift α
k−
i to radiation directivity of each of said antenna elements disposed on the same periphery and for making the phase shift α
k−
i equal to nk times position angle ψ
k−
i, nk being an integer excluding 0,wherein said phase shifting means corresponding to each of said circular antenna arrays are electrically connected to feeding circuits being different from each other. - View Dependent Claims (7, 8, 9, 10, 11)
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Specification