Phased array antenna
First Claim
1. An antenna system for producing from a fixed array of active antenna elements which are each omnidirectional in a plane, a sensitivity pattern that is directional in said plane and which can be rotated around the array, comprising at least three of said elements each located at the corner of a regular polygon, and means for exciting all of the elements with currents of substantially equal magnitudes that are instantaneously in the same phase at two of said corners next adjacent and on either side of a third of said corners, and different in phase by substantially 90 electrical degrees at said third corner, the distance between two adjacent corners of said polygon being in the range substantially one-quarter to substantially 0.288 of the length of a wave at the mid-frequency of the operating frequency band of said system.
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Abstract
An antenna system for producing from a fixed array of active antenna elements which are each omnidirectional in a plane, a sensitivity pattern that is directional in said plane and which pattern can be rotated around the array. The system consists of at least three antenna elements located at the corners of a regular polygon and are excited with substantially equal magnitudes of current that are in the same phase at two adjacent corners and different in phase by substantially 90 electrical degrees at the third corner. The antenna system further includes an electrical power dividing and phasing network as well as electrical switching means to effect proper rotation.
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Citations
22 Claims
- 1. An antenna system for producing from a fixed array of active antenna elements which are each omnidirectional in a plane, a sensitivity pattern that is directional in said plane and which can be rotated around the array, comprising at least three of said elements each located at the corner of a regular polygon, and means for exciting all of the elements with currents of substantially equal magnitudes that are instantaneously in the same phase at two of said corners next adjacent and on either side of a third of said corners, and different in phase by substantially 90 electrical degrees at said third corner, the distance between two adjacent corners of said polygon being in the range substantially one-quarter to substantially 0.288 of the length of a wave at the mid-frequency of the operating frequency band of said system.
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8. A method of generating a directive antenna beam with high gain over approximately 90°
- width, with good front-to-back ratios and good front-to-side ratios which comprises;
(a) aligning four vertical antennas in a square configuration above a ground plane with quarter-wave spacing between adjacent antennas; and (b) feeding each of said antennas with equal amplitudes of power but adjusting the phase such that a first antenna is at 0°
phase, the two antennas adjacent to said first antenna are each at -90°
phase relative to said first antenna, and the fourth antenna is at -180°
phase relative to said first antenna.
- width, with good front-to-back ratios and good front-to-side ratios which comprises;
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9. A method of generating a directive antenna beam with high gain over approximately 120°
- width, with good front-to-back ratios and good front-to-side ratios which comprises;
(a) aligning three vertical antennas in an equilateral triangular configuration above a ground plane with a 0.288 wavelength spacing between adjacent antennas; and (b) feeding each of said antennas with equal amplitudes of power but adjusting the phase such that a first antenna is at 0°
phase and the two adjacent antennas are each at -90°
phase relative to said first antenna.
- width, with good front-to-back ratios and good front-to-side ratios which comprises;
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10. An antenna system for use in general radio communication in HF, VHF, and UHF bands which comprises:
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(a) four vertical antennas in a square configuration above a ground plane with quarter wave spacing between adjacent antennas; (b) a phasing network with four output ports with said output ports connected to said antennas such that when one or more signals are directed toward the input of the network a 0°
phase will be applied to a designated first antenna, a -90°
phase relative to the first antenna will be applied to each of the two antennas adjacent to the first antenna, and a -180°
phase relative to the first antenna will be applied to the fourth antenna;(c) a switching network connected to the said phasing network such that upon activation of the switching network the phasing network will cause a different antenna to become the said designated first antenna thereby steering the antenna array'"'"'s directive beam; and (d) means connected to said switching network for controlling switch activation such that control may be maintained over which antenna will become the said designated first antenna.
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11. An antenna system for use in general radio communication in HF, VHF, and UHF bands which comprises:
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(a) three vertical antennas in an equilateral triangular configuration above a ground plane with a 0.288 wavelength spacing between adjacent antennas; (b) a phasing network with three output ports connected to said antennas such that when one or more signals are directed toward the input of the network a 0°
phase will be applied to a designated first antenna, and a -90°
phase relative to the first antenna will be applied to each of the two antennas adjacent to the first antenna;(c) a switching network connected to the said phasing network such that upon activation of the switching network the phasing network will cause a different antenna to become the said designated first antenna thereby steering the antenna array'"'"'s directive beam; and (d) means connected to said switching network for controlling switch activation such that control may be maintained over which antenna will become the said designated first antenna.
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- 12. An array antenna for radiating or receiving radio waves with directional selectivity, comprising four antenna elements with said elements being placed on the circumference of a circle, said elements equally spaced along said circumference, said elements being electrically coupled to a common transmitter (or receiver) through an electrical power-dividing and phasing network said network having the property that energy from said transmitter will induce radio frequency currents to flow in each of said elements with electrical phases which differ such that two of the said elements which are diametrically opposite have equal phase while one of the others has an advanced phase and the remaining one has a retarded phase, both compared with the phase of the equally-driven pair, the diameter of said circle being substantially equal to 2 quarter-wavelength of a wave at the mid-frequency of the operating frequency band of said array.
- 19. An array antenna for radiating or receiving radio waves with directional selectivity, comprising three antenna elements erected above a ground plane with said elements being placed on the circumference of a circle on said ground plane, equally spaced on said circumference, said elements being coupled to a common transmitter (or receiver) through an electrical power dividing and phasing network which will induce radio frequency currents to flow in two of said elements with equal phase and in the third element with either and advanced or retarded phase compared with the other two, the distance between any two of said elements being substantially 0.288 of the length of a wave at the mid-frequency of the operating frequency band of the array.
Specification