Notched-fed antenna

• US 20050116873A1
• Filed: 01/12/2005
• Published: 06/02/2005
• Est. Priority Date: 07/15/2002
• Status: Active Grant

• Current Assignee: Fractus SA
• Original Assignee: Fractus SA
• Inventors: Soler Castany, Jordi, Puente Baliarda, Carles
• Granted Patent: US 7,342,553 B2
• Time in Patent Office: Days
• US Class Current: 343/795
• CPC Class Codes: H01Q 1/38 formed by a conductive layer on an insulating support patch antennas H01Q9/0407; microstrip dipole antennas H01Q9/065; microstrip slot antennas H01Q13/106; transmission line microstrip antennas H01Q13/206; manufacturing reflecting surfaces using insulating material for supporting the reflecting surface H01Q15/142
• CPC Class Codes: H01Q 21/28 Combinations of substantially independent non-interacting antenna units or systems multiple beam H01Q25/00
• CPC Class Codes: H01Q 5/371 Branching current paths
• CPC Class Codes: H01Q 5/42 using two or more imbricated arrays H01Q5/49 takes precedence
• CPC Class Codes: H01Q 9/04 Resonant antennas
• CPC Class Codes: H01Q 9/045 with particular feeding means for circular polarisation H01Q9/0428
• CPC Class Codes: H01Q 9/16 with feed intermediate between the extremities of the antenna, e.g. centre-fed dipole H01Q9/44 takes precedence
• CPC Class Codes: H01Q 9/28 Conical, cylindrical, cage, strip, gauze, or like elements having an extended radiating surface; Elements comprising two conical surfaces having collinear axes and adjacent apices and fed by two-conductor transmission lines waveguide horns or mouths H01Q13/00; slot antennas H01Q13/00
• CPC Class Codes: H01Q 9/285 Planar dipole H01Q9/065 takes precedence; patch antenna H01Q9/0407
• CPC Class Codes: H01Q 9/30 with feed to end of elongated active element, e.g. unipole H01Q9/44 takes precedence
• CPC Class Codes: H01Q 9/40 Element having extended radiating surface

Abstract

A novel notched-fed antenna is defined in the present invention. The shape of the radiating element is modified by inserting a set of notches next to the feeding area. By means of this configuration, the antenna provides a small performance, a multifrequency behavior or a combination of both effects and hence it can be used in those environments where a compact, small or multiband antenna is required.

Claims

1. A monopole or dipole antenna characterized in that the radiating element includes at least one notch, wherein at least one of said notches intersects at least at one point on the edge of said radiating element, wherein said intersecting point is located at a distance to the feeding point, said distance being shorter than a half the length of the longest edge of the said radiating element, and wherein the maximum width of said notch or notches is narrower than a half of the longest length of said notches.

2. A monopole or dipole antenna according to claim 1 characterized in that the radiating element includes one notch

3. A monopole or dipole antenna according to claim 1 characterized in that the radiating element includes two notches

4. A monopole or dipole antenna according to claim 1 and 3 characterized in that the radiating element includes two notches, wherein the first notch is inserted at one side of the feeding point, and the other is inserted at the opposite side with respect to the feeding point.

5. A monopole or dipole antenna according to claim 3 or 4 wherein the two notches have the same shape.

6. A monopole or dipole antenna according to claim 4 comprising a radiating element with at least a first and a second notch, wherein said second notch is different in shape from said first notch, being such difference in length, shape or both.

7. A monopole or dipole antenna according to any of the preceding claims wherein the antenna includes at least one notch, said notch being shaped as a curve, said curve intersecting itself at least at one point.

8. A monopole or dipole antenna according to any of the preceding claims where the antenna includes at least two notches, said notches intersect one with the other at least at one point.

9. A monopole or dipole antenna according to any of the preceding claims wherein the perimeter of said radiating element is a shape chosen from the following set:

triangular, square, rectangular, trapezoidal, pentagonal, hexagonal, heptagonal or octagonal.

10. A monopole or dipole antenna according to any of the claim 1, 2, 3, 4, 5, 6, 7 or 8 wherein the perimeter of said radiating element has a circular ∘

elliptical shape, and wherein, for a circular or elliptical shape, the longest edge is considered as a quarter of the perimeter of a circular or elliptical shape.

11. A monopole or dipole antenna according to any of the preceding claims wherein at least a portion of said radiating element is a multilevel structure or a loaded structure.

12. A monopole or dipole antenna according to any of the preceding claims wherein at least one notch is a curve composed by a minimum of two segments and a maximum of nine segments which are connected in such a way that each segment forms an angle with their neighbours, wherein, no pair of adjacent segments define a larger straight segment.

13. A monopole or dipole antenna according to any of the preceding claims wherein the shape of at least a portion of one notch is a space-filling curve.

14. A monopole or dipole antenna according to any of the preceding claims where the radiating element includes at least a second conductor parallel to the radiating element, said second conductor being located at a distance from the radiating element smaller than a quarter of the central operating wavelength, and wherein the space between the radiating element and said second conductor can be filled with air or a dielectric or a combination of both.

15. An antenna wherein the radiating element is an aperture antenna, said antenna characterized in that the aperture has the shape of a notched-fed antenna according to any of the preceding claims.

16. An antenna according to any of the preceding claims, wherein said antenna is an element of an antenna array, said array including at least a notched-fed antenna.

17. An antenna according to any of the preceding claims, characterized in that the antenna is shorter than a quarter of the central operating wavelength.

18. An antenna according to any of the preceding claims, characterized in that the antenna features a similar radiation pattern and input impedance at more than once frequency bands.

19. An antenna according to any of the preceding claims characterized in that it is a monopole antenna and includes a conducting or superconducting ground-plane.

20. An antenna according to claim 19 characterized in that the ground-plane is part of a handled case, or part of the metallic structure of a car or train.

21. An antenna according to any of the preceding claims characterized in that the radiating element is printed over a dielectric substrate.

22. An antenna according to any of the preceding claims characterized in that the dielectric substrate is a portion of a window glass of a motor vehicle, part of the metallic structure of a handled telephone.

23. An antenna according to any of the preceding claims characterized in that it is adapted to transmit or receive electromagnetic waves of radio, or TV, or cellular telephone in the bands GSM900, GSM 1800 or UMTS.