BLADE ANTENNA AND WIRELESS LOCAL AREA NETWORK COMPRISING A BLADE ANTENNA

Abstract

Blade antenna suitable for use in a wireless local area network, comprising at least one blade antenna unit and preferably two blade antenna units wherein each unit comprises: a ground plane, a first blade structure which is mounted substantially perpendicular onto the ground plane, wherein the ground plane and first blade structure are at least partially made of an electrically conductive material and are electrically insulated from each other, thereby forming a blade antenna, a body of dielectric material in which the blade structure at least partially is embedded and which functions as a lens structure for electromagnetic waves received or

Claims

1. Blade antenna suitable for use in a wireless local area network, comprising at least one blade antenna unit comprising: a ground plane, a first blade structure which is mounted substantially perpendicular onto the ground plane, wherein the ground plane and first blade structure are at least partially made of an electrically conductive material and are electrically insulated from each other, thereby forming a blade antenna, a body of dielectric material in which the blade structure at least partially is embedded and which functions as a lens structure for electromagnetic waves received or transmitted by the blade antenna.

2. Blade antenna according to claim 1, wherein the at least one blade antenna unit comprises a first blade structure having a circumference which is substantially defined by the polar function: ${\rho }_d\left(\varphi \right)=\frac{1}{\sqrt[n_1]{{.Math.\frac{1}{a}.Math.\cos .Math.\frac{m_1}{4}.Math.}^{n_2}\pm {.Math.\frac{1}{b}.Math.\sin .Math.\frac{m_2}{4}.Math.}^{n_3}}}$ with a,b ∈.sup.+; m.sub.1,m.sub.2,n.sub.1,n.sub.2,n.sub.3 ∈; a,b,n.sub.1 ≠ 0 and wherein: ρ.sub.d(φ) is a curve located in the XY-plane; and φ ∈ [0, 2π) is the angular coordinate.

3. Blade antenna according to claim 1, wherein the at least one blade antenna unit comprises: one or more second blade structures mounted substantially perpendicular onto the ground plane, which are at least partially made of an electrically conductive material and are electrically insulated from the ground plane, and which are at least partially embedded in the lens structure.

4. Blade antenna according to claim 3, wherein at least one second blade structure has a circumference which is substantially defined by the polar function: ${\rho }_d\left(\varphi \right)=\frac{1}{\sqrt[n_1]{{.Math.\frac{1}{a}.Math.\cos .Math.\frac{m_1}{4}.Math.}^{n_2}\pm {.Math.\frac{1}{b}.Math.\sin .Math.\frac{m_2}{4}.Math.}^{n_3}}}$ with a,b, ∈.sup.+; m.sub.1,m.sub.2,n.sub.1,n.sub.2,n.sub.3 ∈; a,b,n.sub.1 ≠ 0 and wherein: ρ.sub.d(φ) is a curve located in the XY-plane; and φ ∈ [0, 2π) is the angular coordinate.

5. Blade antenna according to claim 3, wherein two of the first and second blade structures are virtually identical.

6. Blade antenna according to claim 1, wherein one blade structure of one blade antenna unit, is divided in two main parts that are conductively connected.

7. Blade antenna according to claim 3, wherein one second blade structure of one blade antenna unit, intersects the first blade structure over a common axis.

8. Blade antenna according to claim 1, wherein one blade structure of one blade antenna unit, is configured to operate in the 5 GHz frequency band, wherein the length of said structure is between 4 and 12 mm.

9. Blade antenna according to claim 1, wherein one blade structure of one blade antenna unit, is configured to operate in the 2.4 GHz frequency band, wherein the length of said structure is between 8 and 24 mm.

10. Blade antenna according to claim 1, wherein the height of the lens structure of one blade antenna unit, is smaller than or equal to 30 mm.

11. Blade antenna according to claim 1, wherein the lens structure of one blade antenna unit, has a cylindrical shape.

12. Blade antenna according to claim 1, wherein the dielectric material of the lens structure of one blade antenna unit, has a dielectric constant of between 2 and 90.

13. Blade antenna according to claim 1, wherein the dielectric material of the lens structure of one blade antenna unit, has a refractive index n, wherein n ≠1.

14. Blade antenna according to claim 1, wherein the ground plane of one blade antenna unit, is a substantially circular plane having a diameter of 10 to 15 mm.

15. Blade antenna according to claim 1, wherein one blade antenna unit is configured to communicate in a first frequency band and a second frequency band.

16. Blade antenna according to claim 15, comprising at least one process for switching between two frequency bands.

17. Blade antenna according to claim 1, wherein one blade antenna unit comprises a lens structure that has a base profile which is substantially defined by the polar function: ${\rho }_d\left(\varphi \right)=\frac{1}{\sqrt[n_1]{{.Math.\frac{1}{a}.Math.\cos .Math.\frac{m_1}{4}.Math.}^{n_2}\pm {.Math.\frac{1}{b}.Math.\sin .Math.\frac{m_2}{4}.Math.}^{n_3}}}$ with a,b ∈.sup.+; m.sub.1,m.sub.2,n.sub.1,n.sub.2,n.sub.3 ∈; a,b,n.sub.1 ≠ 0 and wherein: ρ.sub.d(φ) is a curve located in the XY-plane; and φ ∈ [0, 2π) is the angular coordinate.

18. Blade antenna according to claim 1, wherein the blade antenna comprises at least two blade antenna units of which the individual ground planes lie in a common plane or on parallel planes.

19. Blade antenna according to claim 18, wherein the blade antenna units are fixed to each other by a spacing structure.

20-21. (canceled)

22. Blade antenna according to claim 1, containing one blade antenna unit wherein one blade structure has a circumference which is substantially circular or elliptical.

23-24. (canceled)

Description

[0068] The invention will be further explained by a description of the appended figures wherein:

[0069] FIG. 1 shows a preferred embodiment of the blade antenna according to the invention;

[0070] FIG. 2 shows another preferred embodiment of the blade antenna according to the invention;

[0071] FIG. 3 shows a preferred embodiment of a blade antenna integrated in an access point.

[0072] FIG. 1 shows a three dimensional picture of a blade antenna 1 suitable for a wall mounted access point (WLAN), comprising two identical blade antenna units 3 wherein each unit comprises: [0073] a ground plane 5, [0074] a first blade structure 7 which is mounted substantially perpendicular onto the ground plane 5, [0075] a second blade structure 9 which is mounted substantially perpendicular onto the ground plane 5.

[0076] The blade structures 7,9 and the ground plane 5 are made of an electrically conductive material. The two blade structures are in a substantially perpendicular orientation to each other. Each blade structure 7,9 is divided in an upper part and a lower part which are conductively connected by a rod 10. The second blade structure 9 is connected to the first blade structure 7 over a common axis in line with rod 10. The blade structures 7,9 converge at the bottom pin 8 which is conductively connected to a feed line (not shown) provided on the bottom side of the spacing structure 14. The bottom pin 8 extends through an insulating disk 6 of a dielectric material in the center of the ground plane 5. Consequently, the whole blade structure 7,9 is mounted onto the ground plane 5 while being electrically insulated from the ground plane.

[0077] The overall circumference of the blade structures 7,9 is substantially defined by the polar function for a supershape of the Gielis' formula:

[00006]${\rho }_d\left(\varphi \right)=\frac{1}{\sqrt[n_1]{{.Math.\frac{1}{a}.Math.\cos .Math.\frac{m_1}{4}.Math.\varphi .Math.}^{n_2}+/-{.Math.\frac{1}{b}.Math.\sin .Math.\frac{m_2}{4}.Math.\varphi .Math.}^{n_3}}}$

[0078] with m1=m2=4, and the convexity parameters n1, n2, n3 being equal and having a value chosen of 2.5. Furthermore, the supershape is modified by several Boolean operations: By Boolean subtraction of a strip a slot is created which divides the supershape in a lower and an upper part. By Boolean addition of a strip, each lower part is provided with extensions in the form of a strip near the slot.

[0079] Further, each blade antenna unit 3 comprises a lens structure 12 in the form of a cylindrical body 12 of dielectric material in which the blade structures 7,9 are enclosed and which functions as a lens structure for electromagnetic waves received or transmitted by the blade antenna 1. The bottom plane of the lens structure 12 covers the ground plane 5.

[0080] The two blade antenna units 3 are fixed to each other by a spacing structure 14 of electrically insulating material such as used for printed circuit boards, preferably the composite FR4. Not visible are electricity lines at the bottom side of the spacing structure which provide electric feed to the blade structures 7,9.

[0081] FIG. 2 shows a three dimensional picture of a blade antenna 20 suitable for a ceiling mounted access point for a WLAN, comprising one blade antenna unit 23 which comprises: [0082] a ground plane 25, [0083] a first blade structure 27 which is mounted substantially perpendicular onto the ground plane 25, [0084] a second blade structure 29 which is mounted substantially perpendicular onto the ground plane 25.

[0085] The blade structures 27,29 and the ground plane 25 are made of an electrically conductive material. The two blade structures are in a substantially perpendicular orientation to each other. Each blade structure 27,29 is divided in an upper part and a lower part which are conductively connected. The second blade structure 25 is connected to the first blade structure 27 over a common longitudinal axis 34. The overall circumference of the blade structures 27,29 is substantially a circle. The ground plane 25 has a significantly larger diameter than the bottom plane of the lens structure 32, e.g. 4- or 5-fold larger.

[0086] Analogously to FIG. 1, the blade structures 27,29 converge at a bottom pin (not shown) which is conductively connected to a feed line provided below the ground plane 25. The pin extends through the ground plane 25, while being electrically insulated from the ground plane using an insulating structure that surrounds the pin through the ground plane.

[0087] FIG. 3 shows a three dimensional picture of a blade antenna 1 integrated in a wall mounted access point 30 for WLAN. The picture shows the limited space for fitting the blade antenna 1 in the access point 30. The blade antenna 1 is identical to the one pictured in FIG. 1.

EXAMPLES

[0088] The blade antenna 1 depicted in FIG. 1, has the following properties: [0089] dual-band operation at 2.4 GHz and 5.0 GHz; [0090] efficiency of 89% at 2.4 GHz and 96% at 5.0 GHz; [0091] peak gain level of 3.3 dBi at 2.4 GHz and 3.2 dBi at 5.0 GHz.

[0092] The blade antenna 20 depicted in FIG. 2, has the following properties: [0093] dual-band operation at 2.4 GHz and 5.0 GHz; [0094] efficiency of 95% at 2.4 GHz and 95% at 5.0 GHz; [0095] peak gain level above 2.0 dBi at 2.4 GHz and above 3.0 dBi at 5.0 GHz.