ULTRA WIDE BAND ANTENNA WITH A SPLINE CURVE RADIATING ELEMENT

• US 20090189825A1
• Filed: 01/16/2009
• Published: 07/30/2009
• Est. Priority Date: 01/25/2008
• Status: Active Grant

• Current Assignee: Dublin Institute of Technology
• Original Assignee: Dublin Institute of Technology
• Inventors: John, Matthias, Ammann, Max
• Granted Patent: US 8,232,922 B2
• Time in Patent Office: Days
• US Class Current: 343/848
• 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
• CPC Class Codes: H01Q 9/42 with folded element, the folded parts being spaced apart a small fraction of the operating wavelength
• CPC Class Codes: Y10T 29/49016 Antenna or wave energy "plumbing" making

Abstract

The present application relates to microstrip-fed printed planar antennas and in particular to the geometry of same. More particularly an antenna is provided with a radiating or ground plane element having a generally continuous curved shape and being symmetrical about the longitudinal axis and non-symmetrical about an axis transverse to the longitudinal axis.

Claims

1. An antenna comprising:

a radiating element provided on a planar surface;

a ground plane element provided on a planar surface; and

wherein at least the radiating element has a shape defined by a spline curve.

2. The antenna of claim 1 wherein the radiating element is disposed along a longitudinal axis, the radiating element having a generally continuous curved shape and being symmetrical about the longitudinal axis and non-symmetrical about an axis transverse to the longitudinal axis.

3. An antenna according to claim 1, wherein the radiating element is provided on a first planar surface and the ground plane element is provided on a second planar surface, the antenna further comprising a dielectric substrate defining the first and second planar surfaces.

4. An antenna according to claim 1, wherein the antenna is a wide band antenna.

5. An antenna according to claim 1, wherein the antenna is an ultra wide band antenna.

6. An antenna according to claim 1, wherein the antenna has a bandwidth greater than 25% of the center frequency of the antenna.

7. An antenna according to claim 1, wherein the shape of the radiating element and ground plane element is definable by a spline curve.

8. An antenna according to claim 1, wherein the spline curve is a quadratic Bé

zier spline curve.

9. An antenna according to claim 1, wherein the spline curve is defined by a number of control points.

10. An antenna according to claim 9, wherein the number of control points is equal to three or more.

11. An antenna according to claim 8, wherein the expression defining the quadratic Bé

zier curve is given by;

$B_n<br><br>\left(t\right)={\left(1-t\right)}^2<br><br>\left[\begin{array}{c}{P}_{\mathrm{vnx}}\\ P_{\mathrm{vny}}\end{array}\right]+2<br><br><br><br>t<br><br>\left(1-t\right)<br><br>\left[\begin{array}{c}{P}_{\mathrm{nx}}\\ P_{\mathrm{ny}}\end{array}\right]+t^2<br><br>\left[\begin{array}{c}{P}_{\mathrm{vn}+1<br><br><br><br>x}\\ P_{\mathrm{vn}+1<br><br><br><br>y}\end{array}\right];<br><br>$ $t\in <br><br>\left[0,1\right],n\in <br><br>\left[0,N\right]$

where P_vn is a ‘

virtual’

control point placed in the middle of a line defined between two control points P_n and P_n+1 and N is the number of control points and P_N+1 is P₀.

12. An antenna according to claim 1, wherein the antenna is generally ovoid or leaf like in shape.

13. An antenna according to claim 1 provided on a flexible substrate.

14. An antenna according to claim 1 having a folded body.

15. An antenna according to claim 1 wherein each of the radiating element and the ground plane element have a shape defined by a spline curve.

16. An antenna according to claim 1 wherein the antenna has a body, the radiating element and ground plane element being provided on opposing sides of the body.

17. An antenna according to claim 1 is a printed monopole antenna.

18. An antenna according to claim 1 wherein the radiating element has a shape defined by a plurality of spline curves.

19. An antenna comprising:

a radiating element provided on a planar surface;

a ground plane element provided on a planar surface; and

wherein at least the radiating element is disposed along a longitudinal axis of the antenna and has a generally continuous curved shape, the shape being symmetrical about the longitudinal axis and non-symmetrical about an axis transverse to the longitudinal axis.

20. A method of manufacturing an antenna comprising the steps of:

selecting a required design criteria;

selecting a plurality of control points;

establishing a plurality of curved splines employing said control points so as to define at least a radiation element shape; and

adjusting the control points to obtain a radiation element meeting the required design criteria.

21. A method of manufacturing an antenna according to claim 20 wherein the radiation element shape and a ground plane element shape are defined using a plurality of curved splines.

22. A method of manufacturing an antenna according to claim 20, wherein the number of control points is three or more.

23. A method of manufacturing an antenna according to claim 20, further comprising the step of printing the obtained radiation element.

24. A method according to claim 23 further comprising the step of providing a feed to the radiation element.

25. A method according to claim 20, wherein the curved splines are Bé

zier splines.

26. A method according to claim 20, wherein the step of adjusting the control points employs an optimization technique.

27. A method according to claim 26, wherein the optimization technique is a genetic algorithm.

28. A method according to claim 20 where the antenna is a wide band or ultra wide band antenna.

29. A wide band printed antenna comprising

a radiating element provided on a first planar surface,

a ground plane provided on a second planar surface, and

wherein at least the radiating element is disposed along a longitudinal axis, with the radiating element having a generally continuous curved shape and being symmetrical about the longitudinal axis and non-symmetrical along an axis transverse to the longitudinal axis and wherein the shape of the radiating element is definable by a series of spline curves

30. An antenna comprising

a radiating element provided on a first planar surface,

a ground plane element, and

wherein the radiating element is disposed along a longitudinal axis of the antenna, with the radiating element and ground plane having a generally continuous curved shape being symmetrical about the longitudinal axis and non-symmetrical about an axis transverse to the longitudinal axis