Crossed bent monopole doublets

• US 6,356,242 B1
• Filed: 01/27/2000
• Issued: 03/12/2002
• Est. Priority Date: 01/27/2000
• Status: Expired due to Fees

• Current Assignee: George Ploussios
• Original Assignee: George Ploussios
• Inventors: Ploussios, George
• Primary Examiner(s): Wimer, Michael C.
• Application Number:
  US09/492,958
• Time in Patent Office: 775 Days
• Field of Search: H01/Q 2.124, H01/Q 2.126, 343/846, 343/853, 343/844, 343/742, 343/797, 343/828, 343/829, 343/795
• US Class Current: 343/795
• CPC Class Codes: H01Q 21/24 Combinations of antenna units polarised in different directions for transmitting or receiving circularly and elliptically polarised waves or waves linearly polarised in any direction circularly polarised patch antennas H01Q9/0428; circularly polarised horns H01Q13/0241; cross-polarised horns H01Q13/0258; polarisation converters H01Q15/242; cross-polarised rear feeds H01Q19/136; crossed polarisation dual antenna H01Q25/001
• CPC Class Codes: H01Q 21/26 Turnstile or like antennas comprising arrangements of three or more elongated elements disposed radially and symmetrically in a horizontal plane about a common centre
• CPC Class Codes: H01Q 21/29 Combinations of different interacting antenna units for giving a desired directional characteristic H01Q25/00 takes precedence
• CPC Class Codes: H01Q 25/02 providing sum and difference patterns H01Q25/04 takes precedence
• CPC Class Codes: H01Q 9/42 with folded element, the folded parts being spaced apart a small fraction of the operating wavelength

Abstract

An antenna comprising a pair of bent monopole elements (a doublet) that are fed in a manner that results in elevation coverage from the horizon to horizon and dual polarization. Two orthogonal bent monopole doublets provide hemispherical coverage with horizontal and vertical polarization. Combining the doublet terminals through a processing circuit will provide polarization diversity and/or angle diversity capability.

Claims

1. An antenna comprising:

a ground plane having a first surface;

a pair of non-intersecting spaced antenna elements that are up to and including one quarter wavelength in length, extending from the first surface of the ground plane comprising first and second antenna elements with first and second feed points, respectively, wherein both antenna elements extend from the first surface of the ground plane and bend toward the antenna centerline that extends along an axis normal to the ground plane such that a vector representative of each of the elements has at least some horizontal component as viewed against the ground plane and such that the first and second antenna elements are symmetrically located about the antenna centerline; and

at least one splitter/combiner having at least two input terminals and at least one output terminal, the input terminals electrically coupled to separate antenna feed points, whereby the splitter/combiner is for splitting and combining electrical signals when transmitting and receiving signals, respectively.

2. The antenna of claim 1 wherein at least one element is asymmetrically top loaded.

3. The antenna of claim 2 wherein the antenna elements are self-resonant.

4. The antenna of claim 2 wherein the greatest amount of top loading for each asymmetrically top-loaded antenna element is directed towards the antenna centerline that extends along an axis normal to the ground plane.

5. The antenna of claim 2 wherein the cross-section of the asymmetrical top loading for at least one antenna element is rectangular in shape.

6. The antenna of claim 1 wherein the feed points for the antenna element pair are a distance of up to and including approximately one-half wavelength apart at an operating frequency of the antenna.

7. The antenna of claim 1 further including at least one microstrip transmission line electrically coupled to at least one element feed point.

8. The antenna of claim 7 wherein the ground plane has a second surface opposite to the first surface and the microstrip transmission line is coupled to a dielectric substrate coupled to at least one surface of the ground plane.

9. The antenna of claim 1 wherein at least one splitter/combiner shifts the current phase of at least one electrical signal by one hundred eighty (180) degrees.

10. The antenna of claim 1 wherein the length of the electrical coupling between the separate antenna feed points and the two splitter/combiner input terminals differ by approximately one-half wavelength at an operating frequency of the antenna.

11. An antenna comprising:

a ground plane having a first surface;

a pair of non-intersecting spaced antenna elements that are up to and including one quarter wavelength in length, extending from the first surface of the ground plane, symmetrically about an antenna centerline, comprising first and second antenna elements with first and second feed points, respectively;

a second pair of spaced antenna elements of up to and including one quarter wavelength, orthogonal to the first pair of antenna elements and extending from the first surface of the ground plane, symmetrically about the antenna centerline, comprising third and fourth antenna elements with third and fourth feed points, respectively, such that the centerpoint between each pair of antenna elements is identical, wherein at least one antenna element extends from the first surface of the ground plane and bends toward the antenna centerline that extends along an axis normal to the ground plane such that a vector representative of the element has at least some horizontal component as viewed against the ground plane;

a first splitter/combiner having at least two input terminals and at least one output terminal, the input terminals electrically coupled to the first and second antenna feed points, whereby the splitter/combiner is for splitting and combining electrical signals when transmitting and receiving signals respectively; and

a second splitter/combiner having at least two input terminals and at least one output terminal, the input terminals electrically coupled to the third and fourth antenna feed points, whereby the second splitter/combiner is for splitting and combining electrical signals when transmitting and receiving signals respectively.

12. The antenna of claim 11 wherein at least one element is asymmetrically top loaded.

13. The antenna of claim 12 wherein the antenna elements are self-resonant.

14. The antenna of claim 12 wherein the greatest amount of top loading for each asymmetrically top-loaded antenna element is directed towards the antenna centerline that extends along an axis normal to the ground plane.

15. The antenna of claim 12 wherein the cross-section of the asymmetrical top loading for at least one antenna element is rectangular in shape.

16. The antenna of claim 11 wherein the feed points for each antenna element pair are a distance of up to and including approximately one-half wavelength apart at an operating frequency of the antenna.

17. The antenna of claim 11 further including at least one microstrip transmission line electrically coupled to at least one element feed point.

18. The antenna of claim 17 wherein the ground plane has a second surface opposite to the first surface and the microstrip transmission line is coupled to a dielectric substrate coupled to at least one surface of the ground plane.

19. The antenna of claim 11 wherein at least one splitter/combiner shifts the current phase of at least one electrical signal by one hundred eighty (180) degrees.

20. The antenna of claim 11 further including a signal processor having at least two input terminals and at least one output terminal, the input terminals electrically coupled to the output terminals of the first and second splitter/combiners, respectively, the signal processor for splitting and combining electrical signals when transmitting and receiving signals, respectively.

21. The antenna of claim 20 wherein the signal processor is a ninety (90) degree hybrid combiner.

22. The antenna of claim 20 wherein the signal processor includes weighting amplifiers that are coupled to the output terminals of the first and second splitter/combiners, respectively.

23. The antenna of claim 21 wherein the signal processor includes at least one SPDT switch that switches the outputs of each of first and second ports to a sum difference combiner at third and fourth ports, to result in radiation patterns rotated by plus and minus forty five (45) degrees from the radiation patterns of the first and second ports.

24. The antenna of claim 23 comprising at least one SP4T switch allowing a user to select any one of the four ports to obtain the desired signal.

25. An antenna comprising

an imaginary ground plane with first and second surfaces;

a first pair of spaced antenna elements extending from the first surface of the imaginary ground plane;

a second pair of spaced antenna elements orthogonal to the first pair of elements and extending from the first surface of the imaginary ground plane;

such that the centerpoint between the first and second pairs of antenna elements is identical wherein at least one antenna element extends from the first surface of the imaginary ground plane and back toward the antenna centerline that extends along an axis normal to the imaginary ground plane such that a vector representative of the element has at least some horizontal component as viewed against the ground plane;

a third pair of spaced antenna elements extending from the second surface of the imaginary ground plane;

a fourth pair of spaced antenna elements orthogonal to the third pair of elements and extending from the second surface of the imaginary ground plane, such that the centerpoint between the third and fourth pair of antenna elements is identical wherein at least one antenna element extends from the second surface of the imaginary ground plane and back toward the antenna centerline that extends along an axis normal to the imaginary ground plane such that a vector representative of the element has at least some horizontal component as viewed against the ground plane;

a first splitter/combiner with an output port and a second splitter/combiner with an output port; and

a signal processor;

wherein, the third pair and fourth pair of antenna elements are aligned in the same plane as the first pair and second pair of antenna elements thereby causing the first pair and third pair of antenna elements to form a first U-shaped dipole and the second pair and fourth pair of antenna elements to form a second U-shaped dipole; and

each pair of antenna elements in the first U-shaped dipole is electrically coupled to the first splitter/combiner and each pair of antenna elements in the second U-shaped dipole is electrically coupled to the second splitter/combiner, all via a balanced transmission line; and

the output ports of the first and second splitter/combiners are electrically coupled to the signal processor.

26. The antenna of claim 25 wherein the antenna elements are self-resonant.