Calibration apparatus for a switchable antenna array, and an associated operating method
First Claim
1. A method of calibrating a switchable antenna array having a radiation pattern, said antenna array including at least two vertical columns each having at least two antenna elements arranged one above the other, the antenna elements having inputs, said array of the type further including a beam forming network including a Butler matrix connected to the antenna element inputs, the Butler matrix having inputs and outputs and having phase control elements connected to the inputs thereof, the Butler matrix outputs being connected to feed the antenna element inputs in at least one of said columns, the beam forming network producing a different phase relationship between the plural antenna elements depending on which of plural inputs of said Butler matrix are connected to a common feed, in order to achieve a desired beam direction in the azimuth direction, the method comprising:
- feeding at least two of said inputs of the beam forming network simultaneously via a common feed cable arrangement,receiving and processing signals produced by fewer probes associated with a vertical column than there are antenna elements of said vertical column; and
at least in part in response to said received and processed signals, calibrating said antenna array to provide antenna radiation pattern adjustment in azimuthal direction for intermediate azimuthal angles, including trimming the phase control elements to cause the characteristic phase differences associated with the Butler Matrix inputs to intersect at a common calibration point, thereby producing radiation pattern intermediate lobes providing further different azimuth beam directions, such that the radiation pattern lobes produced when at least two inputs are connected can be added with predetermined desired phase.
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Accused Products
Abstract
A calibration device for a switchable antenna array, distinguished by the following improvements provides at least two inputs of two or more available inputs of the beam forming network fed simultaneously and/or jointly and/or in the same phase. The antenna elements have been trimmed in advance in order to produce intermediate lobes or further different azimuth beam directions, such that the individual lobes which are produced when at least two inputs are connected can be added with the correct phase.
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Citations
22 Claims
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1. A method of calibrating a switchable antenna array having a radiation pattern, said antenna array including at least two vertical columns each having at least two antenna elements arranged one above the other, the antenna elements having inputs, said array of the type further including a beam forming network including a Butler matrix connected to the antenna element inputs, the Butler matrix having inputs and outputs and having phase control elements connected to the inputs thereof, the Butler matrix outputs being connected to feed the antenna element inputs in at least one of said columns, the beam forming network producing a different phase relationship between the plural antenna elements depending on which of plural inputs of said Butler matrix are connected to a common feed, in order to achieve a desired beam direction in the azimuth direction, the method comprising:
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feeding at least two of said inputs of the beam forming network simultaneously via a common feed cable arrangement, receiving and processing signals produced by fewer probes associated with a vertical column than there are antenna elements of said vertical column; and at least in part in response to said received and processed signals, calibrating said antenna array to provide antenna radiation pattern adjustment in azimuthal direction for intermediate azimuthal angles, including trimming the phase control elements to cause the characteristic phase differences associated with the Butler Matrix inputs to intersect at a common calibration point, thereby producing radiation pattern intermediate lobes providing further different azimuth beam directions, such that the radiation pattern lobes produced when at least two inputs are connected can be added with predetermined desired phase. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19)
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20. A calibratable, switchable antenna array having a radiation pattern, said antenna array comprising:
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at least two vertical columns each having at least two antenna elements arranged one above the other, the antenna elements having inputs; a beam forming network including a Butler matrix connected to the antenna element inputs, the Butler matrix having inputs and outputs, phase control elements being connected to said Butler matrix inputs, the phase control elements being trimmed to cause phase differences associated with different Butler matrix inputs to converge at common calibration point, thereby producing intermediate lobes of said radiation pattern providing further different azimuth beam directions such that the radiation pattern lobes produced when at least two inputs of Butler Matrix are fed can be added with predetermined desired phase, the Butler matrix outputs being connected to associated antenna array element inputs via which the antenna elements which are provided in at least one column are fed, the beam forming network producing a different phase relationship between the antenna elements which are arranged in the individual columns depending on which of said Butler matrix inputs is connected, in order to achieve a desired beam direction in the azimuth direction; a common feed arrangement coupled to said beam forming network inputs, said feed arrangement feeding at least two of said inputs of the beam forming network simultaneously; at least one probe coupled to the antenna array and positioned in the near field thereof, said probe providing a calibration signal, the number of probes used for calibrating a vertical column being less than the number of antenna elements in the column; and a calibrator coupled to at least said beam forming network phase control elements, said calibrator electronically calibrating said antenna array in response to said calibration signal so as to determine the antenna'"'"'s azimuthal radiation angle, the phase control elements connected to the inputs of the beam forming network acting to adjust the phases of the signals fed to the inputs thereof to thereby cause the antenna array to produce intermediate lobes directed to further different azimuth beam directions. - View Dependent Claims (21, 22)
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Specification