ANTENNA SUITABLE FOR INTEGRATION IN A LAPTOP OR TABLET COMPUTER

Abstract

Antenna of a shape that allows for its integration in a laptop or tablet computer, which antenna has dual band or multi band functionality, and comprises: an elongate carrier structure of electrically insulating material, and an electric circuitry provided on the carrier structure, which comprises the following electrically conductive elements: a ground plane, two or more antenna elements spaced apart from each other, one or more filter elements which are positioned between a pair of adjacent antenna elements, wherein the antenna elements and the filter elements are electrically connected to the ground plane, and wherein the carrier structure contains a feed connector system that allows for an electrical connection between an external feed line and the antenna elements, and wherein the parts of the carrier structure on which the antenna elements are provided, has a relative dielectric constant of at least 2.0, and is of a substantially solid design, which preferably has a minimum cross-sectional area of 0.30 to 1.5 cm2.

Claims

1. Antenna of a shape that allows for its integration in a laptop or tablet computer, which antenna has dual band or multi band functionality, and comprises: an elongate carrier structure of electrically insulating material, and an electric circuitry provided on the carrier structure, which comprises the following electrically conductive elements: a ground plane, two or more antenna elements spaced apart from each other, one or more filter elements which are positioned between a pair of adjacent antenna elements, wherein the antenna elements and the filter elements are electrically connected to the ground plane, and wherein the carrier structure contains a feed connector system that allows for an electrical connection between an external feed line and the antenna elements, and wherein the parts of the carrier structure on which the antenna elements are provided, has a relative dielectric constant of at least 2.0, and is of a substantially solid design.

2. Antenna according to claim 1, wherein each antenna element has a length of 15 mm or smaller in the longitudinal direction of the carrier structure.

3. Antenna according to claim 1, wherein each filter element is an electrically passive element which is not adjustable by a connected circuitry.

4. Antenna according to claim 1, wherein the carrier structure has a first longitudinal side which is substantially free from electrically conductive elements, which side amounts to 20% to 50% of the total longitudinal surface area of the carrier structure.

5. Antenna according to claim 1, wherein the ground plane is mainly provided on a second longitudinal side of the carrier structure, which amounts to 20% to 40% of the total longitudinal surface area of the carrier structure.

6. Antenna according to claim 1, wherein each antenna element and filter element is mainly provided on a third longitudinal side of the carrier structure, which amounts to 30% to 60% of the total longitudinal surface area of the carrier structure.

7. Antenna according to claim 1, wherein the carrier structure has longitudinal sides which comprise a top side, front side, bottom side and back side, wherein each antenna element and filter element is mainly provided on the top side and front side, the ground plane is mainly provided on the back side, and the bottom side is substantially free from electrically conductive elements.

8. Antenna according to claim 1, wherein the carrier structure has a D-shaped cross-section, of which the flat side is substantially free from electrically conductive elements.

9. Antenna according to claim 1, wherein the carrier structure has the shape of a rod of a length of 15 to 20 cm.

10. Antenna according to claim 1, wherein each antenna element has a dual band functionality, and is operative at 2.4 GHz and 5.0 GHz bands.

11. Antenna according to claim 1, wherein the antenna elements are distributed over the length of the carrier structure in a row, wherein each pair of adjacent antenna elements is spaced apart by a similar distance which is approximately half of the wavelength of the lower frequency of the dual band in which the antenna is operative.

12. Antenna according to claim 1, wherein the one or more filter elements are positioned halfway between a pair of adjacent antenna elements.

13. Antenna according to claim 1, wherein each antenna element is individually connected to the ground plane, wherein each filter element is individually connected to the ground plane, and wherein each antenna element is individually connected to the feed connector system.

14. Antenna according to claim 1, wherein each antenna element comprises: an antenna flare structure which is mainly positioned opposite to the ground plane, two antenna arms of which a first antenna arm connects the antenna flare structure with the ground plane, and a second antenna arm connects the antenna flare structure with the feed connector system, wherein the antenna arms are mainly positioned on a top side of the carrier structure.

15. Antenna according to claim 1, wherein each filter element comprises: a filter flare structure which is mainly positioned opposite to the ground plane, a filter arm which connects the filter flare structure with the ground plane, an array of parallel and spaced apart filter strips directly connected to the ground plane, wherein the filter arm and the array are mainly positioned on a top side of the carrier structure.

16. Antenna according to claim 1, wherein the feed connector system comprises insulated feed lines inside the carrier structure, wherein each feed line is connected to the second antenna arm at one end, and at the other end is connectable to an external feed line.

17. Antenna according to claim 1, wherein the carrier structure is provided with bores and recesses for mounting the antenna in a laptop or tablet computer.

18. Antenna according to claim 1, wherein the antenna is a molded interconnect device (MID), wherein the electric circuitry is made via laser direct structuring (LDS).

19. Antenna according to claim 1, wherein the antenna flare structure and/or filter flare structure have a contour that is conformal with the following superformula: ${}_d\left(\right)={\left(|\frac{1}{a}.Math.\cos .Math.\frac{m_1}{4}.Math..Math.{|}^{n_2}.Math.+\text{/}-|\frac{1}{b}.Math.\sin .Math.\frac{m_2}{4}.Math..Math.{|}^{n_3}\right)}^{-\frac{1}{n_1}}$ wherein: d() is a curve located in the XY-plane, [0, 2) is the angular coordinate, m.sub.10 and m.sub.20, and wherein at least one of n.sub.1, n.sub.2, and n.sub.3 does not equal 2.

20. Antenna according to claim 1, further comprising a control element for adjusting the amount of gain produced by the antenna elements.

21. Laptop or tablet computer in which an antenna according to claim 1 is integrated at a location adjacent to the display of the computer.

22. An antenna module suitable for assembling an antenna according to claim 1, comprising: an elongate carrier section of electrically insulating material, and an electric circuitry provided on the carrier structure, which comprises the following electrically conductive elements: a ground plane, an antenna element, wherein the antenna element is electrically connected to the ground plane, and wherein the carrier section contains a feed connector system that allows for an electrical connection between an external feed line and the antenna element, and wherein the carrier section has a relative dielectric constant of at least 2.0, and is of a substantially solid design, which has a minimum cross-sectional area of 0.30 to 1.5 cm.sup.2.

23. Antenna module according to claim 22, wherein the antenna element has a length of 15 mm or smaller in the longitudinal direction of the carrier section.

24. Antenna according to claim 22, wherein the carrier section has a first longitudinal side which is substantially free from electrically conductive elements, which side amounts to 20% to 50% of the total longitudinal surface area of the carrier section.

25. The antenna according to claim 1, wherein the parts of the carrier structure on which the antenna elements are provided has a cross-sectional area of 0.30 to 1.5 cm.sup.2.

26. The antenna according to claim 19, wherein none of n.sub.1, n.sub.2, and n.sub.3 equals 2.

Description

[0110] The invention is further explained by the appended figures that illustrate preferred embodiments wherein:

[0111] FIG. 1 shows a laptop computer provided with an antenna according to the invention;

[0112] FIG. 2 shows in perspective an antenna according to a preferred embodiment of the invention;

[0113] FIG. 3 shows a back side of the antenna;

[0114] FIG. 4 shows a top side of the antenna;

[0115] FIG. 5 shows a detail of the view shown in FIG. 3;

[0116] FIG. 6 shows a cross-section of the antenna;

[0117] FIG. 7 shows an alternative built-up of an antenna using antenna modules according to the invention.

[0118] FIG. 1 shows in an exploded view an antenna 1 provided with three antenna elements 5a, 5b, 5c which is incorporated in a laptop computer 21 between the hinges 26 that connect the screen part 22 to the processor or keyboard part 24. The view is exploded so as to show the position of antenna 1, which is actually hidden underneath the upper surface of the keyboard part 24.

[0119] FIG. 2 shows in perspective the front side and top side of the antenna 1, which consists of a carrier structure 3 of insulating polymer material onto which electric elements are provided such as antenna elements 5a, 5b, 5c, and filter elements 7a, 7b. Each antenna element contains a first antenna arm 51, a second antenna arm 52 and an antenna flare structure 54, which consists of two elongated strips 56 parallel to the longitudinal direction of the carrier structure 3 which strips are connected to each other at one end. The length of the first antenna element 5a is indicated as L1. Each filter element contains an array 71 of filter strips crossways to longitudinal direction of the carrier structure 3, a filter arm 72, and a filter flare structure 72 parallel to the longitudinal direction of the carrier structure 3. Although not visible in FIG. 2, the first antenna arm 51 is connected to a ground plane, the second antenna arm 52 is connected to a feed line, and the filter arm 72 is connected to the ground plane. [0120] The separating distance, or space, between two adjacent antenna elements 5a and 5b is indicated as d1.

[0121] As an additional feature to what is shown in the figures, the antenna flare structures may be realized in a folded manner in order to reduce the area occupation and achieve an enhanced uniformity of radiation where that is needed or useful for the targeted application.

[0122] FIG. 3 shows the back side of the antenna 1 comprising: a ground plane 30 of electrically conductive material, such as copper with nickel and gold coating (when using LDS technology) or silver (when using PDS technology) which extends over virtually the complete back side surface. The carrier structure has been provided with recesses 33 and bores 32 for mounting the antenna inside a laptop computer. Furthermore the carrier structure is provided with connecting points 35 for connecting the feed connector system of the antenna to an external feed line. The feed connector system comprises insulated feed lines inside the carrier structure that are non-visible. Parts of the filter elements 7a,b and the antennas 5a,b,c are visible.

[0123] FIG. 4 shows the top side of the antenna 1 with carrier structure 3, comprising the filter elements 7a,b and the antennas 5a,b,c. On the top side are provided the first and second antenna arm 51, 52, and the array of filter strips 71. Part of the antenna flare structure 54 is visible.

[0124] FIG. 5 shows in detail antenna element 5b as shown in FIG. 3, comprising a feed connector system, consisting of a body 58 which is insulated from the ground plane 30, by parts of the carrier structure 3. The body 58 is connected to the core of an insulated feed line 60 (shown by dotted lines), which is provided inside the carrier structure underneath the ground plane 30. The other end of the feed line 60 is connected to a connecting point 35 as shown in FIG. 3.

[0125] FIG. 6 shows a cross-section perpendicular to the longitudinal direction of the elongate carrier structure 3 at the antenna arm 51, which illustrates that the carrier structure has a D-shaped cross-section, with a given height h1, and width w1. The bottom side 70 is free from electrically conductive elements. The ground plane 30 is provided on the back side, whereas the antenna arm covers the top side and the larger strip 56 of the flare structure is present on the front side.

[0126] FIG. 7 shows an alternative to the antenna structure as depicted in the preceding figures, wherein two separate antenna modules 80 having an antenna element 5b are mounted in line (indicated by dotted line DL) onto a substrate structure 90 (only partly depicted), such that they are separated by a void in between. In between this void, a separate filter module 82 having a filter element 5b is mounted. The antenna elements 5a and filter element 5b are provided on a carrier section 84 of similar longitudinal size as the elements themselves. The modules 80,82 each have their own individual ground plane, and their own individual feed connector. The modules 80,82 have a similar D-shaped cross-section as depicted in FIG. 6.

EXAMPLE

[0127] An antenna according to the appended FIGS. 2-5, and having a dual band frequency of 2.4 GHz and 5.0 GHz was produced. The antenna is a molded interconnect device (MID), wherein the electric circuitry is made via laser direct structuring (LDS). The material from which the antenna is produced was a polymer doped with metal particles. The metallization build-up takes place in copper baths. As a final step, a nickel and a thin layer of gold is applied.

[0128] As an alternative to the above manufacturing method, the antenna can be produced using printed deposited silver (PDS) technology based on a 3D aerosol jet deposition of silver metallization on the surface of the polymer carrier, as well as FluidANT technology useful for the jet deposition of micron-sized silver flake based ink onto the antenna carrier structure.

[0129] The following results were obtained:

[0130] At 2.4 GHz:

[0131] Average Realized Gain of each individual antenna element: up to 3.6 dB.

[0132] Peak Realized Gain: up to 3.1 dBi

[0133] Coupling effect observed between each of the three possible pairs of antenna elements is lower than 19.0 dB.

[0134] At 5 GHz:

[0135] Average Realized Gain of each individual antenna element: up to 4.0 dB

[0136] Peak Realized Gain: up to 4.5 dBi

[0137] Coupling effect observed between each of the three possible pairs of antenna elements is lower than 20.1 dB.

[0138] As an indicator for radiation uniformity, the uniformity of the achieved throughput level has been measured upon rotation of the antenna with respect to the WLAN router.

[0139] The throughput level variation over device rotation measured for the antenna, was less than 10%, and typically in the order of 5%. In particular, this was applicable to a situation with high path attenuation (e.g. a large distance to router). The measured results are valid for a broad range of frequency bands, including 2.4 and 5.0 GHz.

[0140] As an indicator for decorrelation effects, the envelope correlation coefficient (ECC) is used as a standard. An ECC of 0.01 or smaller, was measured for the antenna over a broad range of frequency bands, including 2.4 and 5.0 GHz.