STRIPLINE FED APERTURE COUPLED MICROSTRIP ANTENNA

• US 20020163468A1
• Filed: 05/01/2001
• Published: 11/07/2002
• Est. Priority Date: 05/01/2001
• Status: Active Grant

• Current Assignee: Raytheon Company (Rtx Corporation)
• Original Assignee: Raytheon Company (Rtx Corporation)
• Inventors: Anderson, Joseph M.
• Granted Patent: US 6,492,947 B2
• Time in Patent Office: Days
• US Class Current: 343/700MS
• CPC Class Codes: H01Q 9/0428 radiating a circular polarised wave
• CPC Class Codes: H01Q 9/0457 electromagnetically coupled to the feed line

Abstract

An aperture coupled microstrip patch antenna coupling circuit. Electromagnetic energy propagating along a stripline feedline is coupled through one of the ground plane surfaces through a tuned aperture to an adjacent microstrip feedline device, which may be a microstrip patch antenna. Undesirable propagation modes are suppressed by enclosing the aperture-coupled slot in a non-resonant cavity. Impedance matching is accomplished with an impedance matching section.

Claims

1. An stripline aperture coupling device, comprising:

a stripline feedline having first and second ground planes and a feedline;

an aperture opening formed in said first ground plane, and

a means for controlling electromagnetic coupling between said feedline and said aperture opening.

2. The apparatus of claim 1, and wherein said means is a non-resonant cavity.

3. The apparatus of claim 2, and wherein said non-resonant cavity is formed from at least one conductor.

4. The apparatus of claim 3, and wherein said at least one conductor is disposed between said first and second ground planes.

5. The apparatus of claim 2, and wherein said at least one conductor is a plated through hole.

6. The apparatus of claim 1, further comprising a circuit element located adjacent to said aperture opening and wherein electromagnetic energy is coupled from said feedline to said circuit element.

7. The apparatus of claim 6, and wherein said circuit element is an antenna.

8. The apparatus of claim 7, and wherein said antenna is a microstrip patch antenna.

9. The apparatus of claim 8, and wherein said microstrip patch antenna is a comer clipped microstrip patch antenna.

10. The apparatus of claim 1, and wherein said aperture opening is resonant.

11. The apparatus of claim 10, and wherein said resonant opening is one-half wavelength long.

12. The apparatus is claim 10, and wherein said resonant opening is folded.

13. The apparatus of claim 12, and wherein said resonant opening is folded in a ‘

U’

shape.

15. The invention of claim 14 further comprising:

an impedance matching section coupled to said first end of said feedline that converts the impedance of said feedline to match the impedance of said resonant opening.

16. The invention of claim 15 wherein said impedance matching section is a one-quarter wavelength stub.

17. The invention of claim 14 wherein said resonant opening has a slot shape of approximate one-half wavelength length.

18. The invention of claim 17 wherein said resonant opening slot shape is folded.

19. The invention of claim 17 wherein said resonant opening slot shape is folded in a ‘

U’

shape.

20. The invention of claim 14 wherein said antenna is a microstrip patch antenna.

21. The invention of claim 14 wherein said antenna is a microstrip patch antenna, and further comprising:

a second dielectric material located between said microstrip patch antenna and said first ground plane.

22. The invention of claim 21 wherein said microstrip patch antenna is a corner-clipped microstrip patch antenna.

23. The invention of claim 14 wherein said plurality of conductors are plated through holes.

25. The invention of claim 24 further comprising:

an impedance matching section coupled to said first end of said feedline that converts the impedance of said feedline to match the impedance of said resonant opening.

26. The invention of claim 25 wherein said impedance matching section is a one-quarter wavelength stub.

27. The invention of claim 24 wherein said resonant opening has a slot shape of approximate one-half wavelength length.

28. The invention of claim 27 wherein said resonant opening slot shape is folded.

29. The invention of claim 27 wherein said resonant opening slot shape is folded in a ‘

U’

shape.

30. The invention of claim 24 wherein said plurality of conductors are plated through holes.

14. An aperture coupled antenna, comprising:

a stripline feedline having a first ground plane and a second ground plane positioned substantially parallel to each other with a first dielectric material disposed therebetween, and having a feedline with a first end located within said first dielectric material;

a resonant opening, formed through said first ground plane, located adjacent to said first end of said feedline;

a non-resonant cavity, formed from a plurality of conductors connected between said first and second ground planes, located about said resonant opening;

an antenna located adjacent to said resonant opening on the opposite side of said first ground plane from said feedline, and wherein

electromagnetic energy is coupled between said feedline and said antenna through said resonant opening.

24. A stripline to microstrip coupling circuit, comprising:

a stripline feedline having a first ground plane and a second ground plane positioned substantially parallel to each other with a first dielectric material disposed there between, and having a feedline with a first end located within said first dielectric material;

a resonant opening, formed through said first ground plane, located adjacent to said first end of said feedline;

a non-resonant cavity, formed from a plurality conductors connected between said first and second ground planes, located about said resonant opening;

a stripline conductor supported by a second dielectric material on the opposite side of said first ground plane from said feedline, said stripline conductor located adjacent to said resonant opening, and wherein

electromagnetic energy is coupled between said feedline and said stripline conductor through said resonant opening.