Trap microstrip PIFA

• US 6,380,895 B1
• Filed: 04/06/2000
• Issued: 04/30/2002
• Est. Priority Date: 07/09/1997
• Status: Expired due to Fees

• Current Assignee: AMC Centurion AB (DuPont de Nemours, Inc.)
• Original Assignee: Allgon AB (Bure Equity AB)
• Inventors: Moren, Stefan, Rowell, Corbett
• Primary Examiner(s): Wong, Don
• Assistant Examiner(s): VANNUCCI, JAMES
• Application Number:
  US09/462,086
• Time in Patent Office: 754 Days
• Field of Search: 343/700.MS, 343/822, 343/725, 343/751
• US Class Current: 343/700.0MS
• CPC Class Codes: H01Q 1/243 with built-in antennas
• CPC Class Codes: H01Q 1/244 extendable from a housing along a given path
• CPC Class Codes: H01Q 1/36 Structural form of radiating elements, e.g. cone, spiral, umbrella; Particular materials used therewithH01Q1/08, H01Q1/14 take precedence
• CPC Class Codes: H01Q 5/321 within a radiating element or between connected radiating elements
• CPC Class Codes: H01Q 5/371 Branching current paths

Abstract

The present invention relates to a small microstrip antenna device, mountable inside a hand-held radio communication device, for receiving and transmitting RF signals in one or more frequency bands. The microstrip antenna comprises a ground plane means (101), at least a first feeding means (107) and N radiating elements where N is an integer greater than zero. The microstrip antenna structure also has a first conductive path (104). The feeding means is arranged on the first patch for feeding radio frequency signals to the N radiating elements, wherein at least a first of the N radiating elements has a second patch (106). The second patch is inductively coupled (108) to the first patch.

Claims

1. A microstrip antenna structure for receiving and transmitting radio frequency signals in at least two frequency bands, comprising:

a ground plane means,

at least a first feeding means and,

N radiating elements where N is an integer number greater than zero,

said microstrip antenna structure having a first conductive patch,

said feeding means being arranged for feeding radio frequency signals to the first patch,

at least a first of the N radiating elements having a second patch,

inductive means for inductively coupling the second patch to said first patch and,

said second patch having a free end.

2. The structure according to claim 1 wherein,

said first and second patch being thin conductive layers on a dielectric carrier,

said ground plane means substantially coextending with said N radiating means being arranged in proximity to the patches.

3. The structure according to claim 1 wherein,

said second patch having a substantially rectangular shape.

4. The structure according to claim 1 wherein,

said first and second patch being arranged at a specific distance from each other to attain, in addition to the inductive coupling, a capacitive coupling between the first and second patch with a specific capacitance.

5. The structure according to claim 1 wherein,

first capacitive means being arranged for attaining in addition to the inductive coupling, a capacitive coupling said first patch to the second patch.

6. The structure according to claim 1 wherein,

said inductive means is formed by at least one discrete component held by retainer means for inductively coupling said first and second patches to each other.

7. The structure according to claim 6 wherein,

said retainer means comprise first and second protrusions arranged on a dielectric substrate for retaining the discrete component.

8. The structure according to claim 1 wherein,

N is equal to one and,

said first patch being substantially rectangular.

9. The structure according to claim 1 wherein,

at least a second of the N radiating elements is an elongated conductive strip having a free end.

10. The structure according to claim 1 wherein,

N is greater than one,

said first conductive patch comprises at least a first protruding part,

at least a second radiating element comprises a third substantially rectangular conductive patch,

inductive means being arranged for inductively coupling said third patch to the first protruding part and,

said third patch having a free end.

11. The structure according to claim 1 wherein,

at least one of the N radiating elements having a capacitive coupling to the ground plane means at the free end,

said capacitive coupling being adjusted to a specific capacitance.

12. The structure according to claim 11 wherein,

a conductive extension means extending towards the ground plane means so as to attain the capacitive coupling.

13. The structure according to claim 11 wherein,

said antenna structure further comprising a discrete component achieving the capacitive coupling.

14. The structure according to claim 1 wherein,

said inductive means is a meandering conductive strip.

15. The structure according to claim 1 wherein,

said inductive means is a coil.

16. The structure according to claim 1 wherein,

said inductive means is a tunable, active inductor.

17. The structure according to claim 1 wherein,

said N radiating elements being arranged substantially parallel to each other.

18. The structure according to claim 1 wherein,

N being three,

said first patch having three protruding parts essentially forming a Y-shape and,

first, second and third radiating elements extending from said protruding parts.

19. The structure according to claim 1 wherein,

N being three,

said first patch having three protruding parts essentially forming a T-shape and,

first, second and third radiating elements extending from said protruding parts.

20. The structure according to claim 1 wherein,

N being three,

first and second radiating elements extending essentially parallel in a first direction and,

a third radiating element extending in an opposite direction to the first direction.

21. The structure according to claim 1 wherein,

N being four,

said first patch having four protruding parts essentially forming a cross shape and,

first, second, third and fourth radiating elements extending from the protruding parts.

22. The structure according to claim 1 wherein,

N being four,

said first patch having four protruding parts essentially forming a H-shape and,

first, second, third and fourth radiating elements extending from said protruding parts.

23. The structure according to claim 1 wherein,

coupling means being arranged for coupling the first patch to ground.