Microstrip patch antenna array

• US 5,572,222 A
• Filed: 08/11/1995
• Issued: 11/05/1996
• Est. Priority Date: 06/25/1993
• Status: Expired due to Fees

• Current Assignee: Allen Telecom Inc. (CommScope Holding Company, Inc.)
• Original Assignee: Allen Telecom Group, Inc.
• Inventors: Mailandt, Peter, Huynh, Tan D.
• Primary Examiner(s): Hajec, Donald T.
• Assistant Examiner(s): Wigmore, Steven
• Application Number:
  US08/514,132
• Time in Patent Office: 452 Days
• Field of Search: 343/700 MS
• US Class Current: 343/700.0MS
• CPC Class Codes: H01Q 21/0075 Stripline fed arrays H01Q21/065 takes precedence
• CPC Class Codes: H01Q 21/08 the units being spaced along or adjacent to a rectilinear path waveguide fed H01Q21/0037

Abstract

A microstrip patch antenna array incorporating a plurality of spaced-apart patch radiating elements electromagnetically coupled to a microstrip line conductively coupled to a source of signals. Both the spaced-apart patch radiating elements and the microstrip line are located on the same side of an adjacent conductive substrate. The microstrip patch radiating elements are arranged in a linear co-planar array electromagnetically excited by the field created by the air substrated microstrip line passing adjacent thereto.

Claims

1. A microstrip patch antenna array comprising:

a conductive substrate;

a continuous conductive elongated microstrip line of finite length extending entirely along a straight line, having opposed ends, and spaced from said conductive substrate;

a connector having a conductor connected to said elongated microstrip line at a feed point located intermediate the ends thereof;

a plurality of generally rectangular patch radiating elements disposed at selected positions along the length of said microstrip line on the side of said microstrip line opposite from said conductive substrate, each of said patch radiating elements having a width and length greater than the width of said microstrip line and including a coupling portion disposed generally centrally thereof and having a peripheral edge, and an outer radiating portion surrounding said coupling portion, said coupling portion being physically separated from said radiating portion by an elongate slot extending along a substantial portion of said peripheral edge thereof, said coupling portion being connected to said radiating portion at a boundary therebetween, each of said patch radiating elements being spaced one from the other and insulated from said conductive substrate and from said microstrip line and positioned adjacent to said microstrip line with said microstrip line disposed underneath a portion of said elongate slot of each of said patch radiating elements, and with said coupling portion of each of said patch radiating elements being disposed over said elongated microstrip line, for electromagnetic excitation therefrom in response to a signal applied to said microstrip line at said feed point, and said coupling portion, said elongate slot, and outer radiating portion of each of said patch radiating elements being disposed on either side of said elongated microstrip line.

2. A microstrip patch antenna array as claimed in claim 1 wherein said conductive substrate acts as a ground plane.

3. A microstrip patch antenna array as claimed in claim 1 wherein the ends of said elongated microstrip conductive line are conductively connected to said conductive substrate.

4. A microstrip patch antenna array as claimed in claim 1 wherein said coupling portion of each of said patch radiating elements is positioned to be bisected by said elongated microstrip line.

5. A microstrip patch antenna array as claimed in claim 1 wherein the distance from the center of each of said patch radiating elements to the center of an adjacent one of said patch radiating elements is approximately equal to one wavelength for the operating frequency range of said microstrip patch antenna array.

6. A microstrip patch antenna array as claimed in claim 1 including an even number of said patch radiating elements wherein half of said radiating elements are disposed on one side of said feed point and the remaining elements are disposed on the other side of said feed point.

7. A microstrip patch antenna array as claimed in claim 6 wherein the orientation of said patch radiating elements on one side of said feed point is reversed from the orientation of said patch radiating elements on the other side of said feed point.

8. A microstrip patch antenna array as claimed in claim 7 wherein the distance from the feed point to the boundary between the coupling and radiating portions of the patch radiating elements is about equal to an odd number of one-quarter wavelengths.

9. A microstrip patch antenna array as claimed in claim 8 wherein the distance between the feed point and the two closest ones of said radiating elements differs by about one-half wavelength.

10. A microstrip patch antenna array as claimed in claim 1 including a tuning member disposed along and connected to said elongated microstrip line and disposed between said feed point and one of the two closest ones of said radiating elements and immediately adjacent an edge thereof.

11. A microstrip patch antenna array as claimed in claim 10 wherein said tuning member is disposed in part below said radiating elements.

12. A microstrip patch antenna array as claimed in claim 1 wherein the sides of said patch radiating elements oriented generally parallel to said elongated microstrip line are approximately one-half wavelength.

13. A microstrip patch antenna array as claimed in claim 1 in which the spacing between said elongated microstrip line and said conductive substrate is greater than the spacing between said elongated microstrip line and said patch radiating elements.

14. A microstrip patch microstrip antenna array as claimed in claim 1 wherein said antenna is adapted for use at frequencies between about 1.6 GHz and about 2.1 Ghz.

15. A microstrip patch antenna array as claimed in claim 14 wherein the dimension of the sides of said patch radiating elements oriented generally parallel to said elongated microstrip line is about 2.6 inches, and said patch radiating elements are constructed from a metal sheet having a thickness of about 0.062 inch.

16. A microstrip patch antenna array as claimed in claim 15 in which the distance between the elongated microstrip feed line and said conductive substrate is about 0.335 inch and the distance between each of said radiating elements and said ground plane is about 0.675 inch.

17. A microstrip patch antenna array as claimed in claim 16 in which the width of said coupling portion of each of said patch radiating elements is about 0.875 inch, and the boundary between the coupling portion and said radiating portion is about 0.8 inch from the adjacent edge of said patch radiating element.

18. A microstrip patch antenna as claimed in claim 17 in which said antenna array exhibits a bandwidth of approximately 20% with a VSWR no greater than 1.5:

1.

19. A microstrip patch antenna array as claimed in claim 1 in which the spacing between said elongated microstrip line and said conductive substrate is less than the spacing between said conductive substrate line and said patch radiating elements.