Antenna arrays of internally phased elements

• US 3,925,784 A
• Filed: 02/06/1974
• Issued: 12/09/1975
• Est. Priority Date: 10/27/1971
• Status: Expired due to Term

• Current Assignee: Harry R. Phelan
• Original Assignee: Harry R. Phelan
• Inventors: Phelan, Harry R.
• Primary Examiner(s): Lieberman, Eli
• Application Number:
  US05/440,182
• Time in Patent Office: 671 Days
• Field of Search: 343/754,854,895,797
• US Class Current: 343/754
• CPC Class Codes: H01Q 15/22 functioning also as polarisation filter
• CPC Class Codes: H01Q 23/00 Antennas with active circuits or circuit elements integrated within them or attached to them
• CPC Class Codes: H01Q 3/2647 Retrodirective arrays
• CPC Class Codes: H01Q 3/46 Active lenses or reflecting arrays

Abstract

An antenna array which receives radio waves and reradiates them in a controllable direction. Direction of the reradiated wave is controlled by controlling the phase relationship between waves reradiated from individual antennas which are elements of the complete array assembly. Phase control of the individual element antennas is effected by altering the relative phase between the received wave and the reradiated wave for each individual element antenna. The phase of the received signal is controlled at terminals on the individual antennas at which that received signal arrives. The phase-altered signal is reapplied to those terminals to serve as an excitation signal for the antenna for causing a reradiated wave to be emitted. The difference between the direction of the reradiated wave and the direction of the received wave is controlled by diode switches or by varactor diodes (or by both) which can be mounted integrally with the individual element antennas of the array assembly.

Claims

1. A passive antenna for receiving and reradiating electromagnetic waves comprising:

at least three electrically conductive arms each having an inner end and an outer end, said arms being spaced apart and symmetrically arranged in a plane and having a common center such that AC electrical signals are induced in said arms by a received electromagnetic wave and in such a manner that said respective signals differ in phase among said arms, and interconnecting means located proximate to said inner arm ends at said common center and in said plane for connecting a selected pair of said inner arm ends together with essentially a short circuit for reapplying said phase differing signals to the interconnected arms in such a manner that an electromagnetic wave radiates from the antenna with a phase relationship with respect to the received electromagnetic wave that is determined by the selected interconnections of said inner arm ends.

2. An antenna as set forth in claim 1 wherein the interconnecting means comprises a plurality of switching diodes, and means for selectively actuating said diodes into conduction or nonconduction so that the relative phases of the reapplied signals are determined by a choice made among received signals of differing phases to be reapplied to the arms by the switching diodes.

3. An antenna as set forth in claim 2 wherein said plurality of electrically conductive arms comprises frequencyindependent antenna means having a frequency-independent phase shift between said received electromagnetic wave and said received signals and between said reapplied phase-differing signals and said radiated electromagnetic wave, whereby said phase relationship between said received and radiated electromagnetic waves is independent of frequency of the waves over a range of frequencies.

4. An antenna as set forth in claim 2 wherein the means for actuating said diodes comprises static switching means.

5. An antenna as set forth in claim 1 wherein the interconnecting means coMprises a plurality of switching means, and means for selectively actuating said switching means so that the relative phases of the reapplied signals are determined by a choice made among received signals of differing phases to be reapplied to the arms by the switching means.

6. A passive antenna for receiving radiated electromagnetic waves and reradiating them, comprising:

a plurality of electrically conductive arms in which A.C. electrical signals are induced by a received electromagnetic wave, and means for selectively changing the relative phases among the arms of the signals and for reapplying the phase-differing signals to the arms, by transmission and reflection, whereby the phase-differing signals in the arms induce an electromagnetic wave that radiates from the antenna with a phase relationship with respect to the received electromagnetic wave that is affected by the changes in the phases of the signals, said electrically conductive arms being arms of a multi-arm spiral antenna, and the means for selectively changing the relative phases and reapplying the signals are proximate to the inner ends of the spiral arms, and are controlled by a further element, namely, control means connected proximately to the outer ends of the conductive arms.

7. A passive antenna for receiving radiated electromagnetic waves and reradiating them, comprising:

a plurality of electrically conductive arms in which A.C. electrical signals are induced by a received electromagnetic wave, and means for selectively changing the relative phases among the arms of the signals and for reapplying the phase-differing signals to the arms, by transmission and reflection, whereby the phase-differing signals in the arms induce an electromagnetic wave that radiates from the antenna with a phase relationship with respect to the received electromagnetic wave that is affected by the changes in the phases of the signals, said electrically conductive arms being arms of a spiral antenna, and the means for selectively changing the relative phases and reapplying the signals are proximate to the outer ends of the spiral.

8. A passive antenna for receiving radiated electromagnetic waves and reradiating them, comprising:

a plurality of electrically conductive arms in which A.C. electrical signals are induced by a received electromagnetic wave, and means for selectively changing the relative phases among the arms of the signals and for reapplying the phase-differing signals to the arms, by transmission and reflection, whereby the phase-differing signals in the arms induce an electromagnetic wave that radiates from the antenna with a phase relationship with respect to the received electromagnetic wave that is affected by the changes in the phases of the signals, said electrically conductive arms being arms of a multiple-arm spiral antenna, and some of the means for selectively changing the relative phases and reapplying the signals are proximate to the inner ends of the spiral arms for affecting received signals having one direction of rotation, and others of such means are proximate to the outer ends of the spiral arms for affecting received signals having the opposite direction of rotation.

9. A passive antenna array for receiving radiated electromagnetic waves and reradiating them, comprising:

a plurality of electrically conductive arms spaced from each other and oriented relative to each other such that A.C. electrical signals are induced in said arms by a received electromagnetic wave and in such a manner that said respective signals differ in phase among said arms, and phase shifting means for selectively changing the relative phases of said signals among the arms and including interconnecting means for selectively interconnecting selected ones of the arm ends of the same sense for selectively reapplying the phase-differing signals to the arms, by transmission and reflection, in such a manner that an electromagnetic wave radiates from the antenna wIth a phase relationship with respect to the received electromagnetic wave that is determined by the selected interconnection of said arm ends, an array of said element antennas wherein the impinging wave strikes the array of element antennas on the same side of the array as that from which the resultant reradiated array wave leaves the antenna for propagation principally in the controllable directions, each of said element antennas comprises frequency-independent antenna means having a frequency-independent phase shift between said impinging wave and said received A.C. signals and between said reapplied A.C. signals and said reradiated elemental antenna waves, and wherein the array of element antennas forms a parabolic contour having a focus for one of said impinging and reradiating waves on the geometric axis of symmetry of said contour, and the array'"'"''"'"'s dimensions transverse to the axis of the parabolic contour are at least as great as five wavelengths of the A.C. signals, whereby said reradiated wave when propagating externally from said array remains collimated substantially independently of the frequency of the A.C. signals.

10. A passive antenna array for receiving electromagnetic waves and reradiating them in a controllable direction, comprising:

a plurality of element antennas that receive A.C. signals from an impinging wave, and means for reapplying the received A.C. signals to the element antennas with signal phases that differ controllably among the element antennas, to excite the element antennas to reradiate elemental antenna waves having signal phases that differ among themselves by amounts that cause a resultant reradiated array wave which the elemental antenna waves cooperate to form, to propagate principally in controllable directions from the array, under control of the means for reapplying the received A.C. signals, said element antennas being multiple-arm spiral antennas, and the means for reapplying the received A.C. signals are proximate to the inner ends of the spiral arms, and are controlled by a further element, namely, control means connected proximately to the outer ends of the conductive arms.

11. A passive antenna for receiving radiated electromagnetic waves and reradiating them, comprising:

a plurality of electrically conductive arms spaced from each other and oriented relative to each other such that A.C. electrical signals are induced in said arms by a received electromagnetic wave and in such a manner that said respective signals differ in phase among said arms, and phase shifting means for selectively changing the relative phases of said signals among the arms and including interconnecting means for selectively interconnecting selected ones of the arm ends of the same sense for selectively reapplying the phase-differing signals to the arms, by transmission and reflection, in such a manner that an electromagnetic wave radiates from the antenna with a phase relationship with respect to the received electromagnetic wave that is determined by the selected interconnection of said arm ends, said received and the reradiated electromagnetic waves have rotating polarization and wherein said electrically conductive arms are arms of a multi-arm spiral antenna, and wherein said interconnecting means includes means proximate the inner ends of the arms.

12. A passive antenna for receiving radiated electromagnetic waves and reradiating them, comprising:

a plurality of electrically conductive arms spaced from each other and oriented relative to each other such that A.C. electrical signals are induced in said arms by a received electromagnetic wave and in such a manner that said respective signals differ in phase among said arms, and phase shifting means for selectively changing the relative phases of said signals among the arms and including interconnecting means for selectively interconnecting selected ones of the arm ends of the same sense for selectively reapplying the phase-diffEring signals to the arms, by transmission and reflection, in such a manner that an electromagnetic wave radiates from the antenna with a phase relationship with respect to the received electromagnetic wave that is determined by the selected interconnection of said arm ends, said received and reradiated electromagnetic waves have rotating polarization and wherein said electrically conductive arms are arms of a multi-arm spiral antenna and said interconnecting means include means proximate the outer ends of the arms.

13. A passive antenna for receiving radiated electromagnetic waves and reradiating them, comprising:

a plurality of electrically conductive arms spaced from each other and oriented relative to each other such that A.C. electrical signals are induced in said arms by a received electromagnetic wave and in such a manner that said respective signals differ in phase among said arms, and phase shifting means for selectively changing the relative phases of said signals among the arms and including interconnecting means for selectively interconnecting selected ones of the arm ends of the same sense for selectively reapplying the phase-differing signals to the arms, by transmission and reflection, in such a manner that an electromagnetic wave radiates from the antenna with a phase relationship with respect to the received electromagnetic wave that is determined by the selected interconnection of said arm ends, said received and reradiated electromagnetic waves are rotationally polarized waves and wherein said plurality of spaced apart electrically conductive arms comprises a plurality of rotationally angularly spaced apart electrically conductive arms for receiving and reradiating said rotationally polarized waves, whereby a change in said phase relationship effectively electrically rotates the antenna for said reradiated signals.

14. A passive element antenna comprising:

a plurality of electrically conductive spiral arms spaced from each other, said arms having a common axis of rotation, each said arm having inner and outer ends, said inner ends being rotationally displaced about said axis relative to each other by a given angle to achieve a given rotational phase progression about said common axis; and

phase control means for effectively electrically rotating said spiral arms about said axis to control the phase relationship of electromagnetic energy to be radiated from said element antenna comprising interconnecting means for interconnecting at least one pair of said inner arm ends together so that electrical signals in said respectively interconnected pair of arms are interchanged from one arm to the other thereof with a relative phase change dependent upon the rotational phase relationship between said interconnected inner arm ends.

15. An element antenna as set forth in claim 14 for use in receiving and reradiating electromagnetic waves and wherein said arms are oriented such that AC electrical signals are induced in said arms by a received electromagnetic wave in such a manner that the respectively induced signals differ in phase among said arms whereby the electromagnetic energy reradiated from said element antenna exhibits a phase relationship with respect to the received electromagnetic energy that is determined by said interconnected inner arm ends.

16. An element antenna as set forth in claim 14, wherein said plurality of spiral arms includes a plurality of pairs of said arms and said interconnecting means includes means for selectively interconnecting the inner arm ends of at least one said pair of arms.

17. An element antenna as set forth in claim 16 wherein said interconnecting means includes switching means located proximate to said inner arm ends.

18. An element antenna as set forth in claim 17 wherein said plurality of arms and said switching means define a coplanar structure.

19. An element antenna as set forth in claim 14 wherein said plurality of spiral arms includes N pairs of arms, wherein N is at least one, and said interconnecting means includes switching means arranged to selectively interconnect at least one of N pairs of said inner arm ends, whereby said element antenna is selectively operable at one of 2N phase states.

20. An element antenna as set forth in claim 19, wherein said switching means is proximate to said inner arm ends.

21. An element antenna as set forth in claim 20 wherein said switching means and said N pairs of arms define a coplanar structure.

22. A passive element antenna comprising:

at least three elongated electrically conductive arms;

said arms being spaced from each other, said arms having inner and outer ends, said inner arm ends being rotationally displaced about a common axis of rotation by a given angle to achieve a given rotational phase progression about said axis so that AC electrical signals are induced in said arms from received electromagnetic energy such that the respective signals in the plurality of arms differ in phase from each other in accordance with said phase progression; and

control means for controlling said element antenna to reradiate electromagnetic energy phase relationship with respect to the received electromagnetic energy and comprising interconnecting means located proximate to said inner arm ends for interconnecting selected ones of the inner arm ends with essentially a short circuit so that at least one pair of said inner arm ends is interconnected by essentially a short circuit so that the phase differing signals in the two interconnected arms of said at least one pair are interchanged from one arm to the other thereof such that an electromagnetic wave radiates from the element antenna with a phase relationship relative to said received energy in dependence upon the selected interconnection.

23. An element anntenna as set forth in claim 22 wherein said arms extend outwardly of said common axis from said inner arm ends to said outer arm ends.

24. An element antenna as set forth in claim 23 wherein said arms are coplanar.

25. A passive element antenna comprising:

at least three electrically conductive arms spaced from each other, said arms being rotationally displaced from each other about a common axis of rotation, each said arm having inner and outer ends, said inner ends being rotationally displaced about said axis relative to each other by a given angle to achieve a given rotational phase progression about said common axis, and control means for effectively electrically rotating said arms about said axis to control the phase relationship of electromagnetic energy to be radiated from said element antenna comprising interconnecting means located proximate to said inner arm ends for interconnecting at least one pair of said inner arm ends together with essentially a short circuit so that electrical signals in said respectively interconnected pair of arms are interchanged from one arm to the other thereof with a relative phase change dependent upon the rotational phase relationship between said interconnected inner arm ends.

26. An element antenna as set forth in claim 25, wherein said arms are spiral arms of the same winding sense.

27. A element antenna as set forth in claim 25, wherein said arms are of like configuration.

28. An element antenna as set forth in claim 25, wherein said arms are of like configuration both in shape and size.

29. An element antenna as set forth in claim 28, wherein said arms are spiral arms of the same winding sense.

30. An element antenna as set forth in claim 28, wherein said arms and said interconnecting means are coplanar.