TECHNICAL FIELD

The disclosure relates to an antenna element for an electronic device comprising a conductive structure comprising an aperture and a coupling arrangement extending at least partially across the aperture.

BACKGROUND

The size of electronic devices, such as tablets and mobile phones, is an important consideration when designing electronic devices. There is movement towards very large displays which cover as much as possible of the electronic device, making the space available for antennas very limited and forcing either the size of the antennas to be significantly reduced, and performance impaired, or a large part of the display to be inactive.

Furthermore, electronic devices need to support more and more radio signal technology such as 2G/3G/4G radio. For coming 5G radio technology, the frequency bands will be expanded to cover frequencies up to 40 GHZ, thus requiring the addition of a number of new wide-band antennas in addition to the existing antennas.

Additionally, electronic devices oftentimes comprise a metal housing, for at least aesthetic reasons. This, in combination with the large display, leaves narrow dielectric gaps between display and frame which limit the possible electrical fields transmitted or received by the antennas.

SUMMARY

It is an object to provide an improved antenna element. The foregoing and other objects are achieved by the features of the independent claims. Further implementation forms are apparent from the dependent claims, the description, and the figures.

According to a first aspect, there is provided an antenna element for an electronic device comprising a conductive structure comprising an aperture, a coupling arrangement extending at least partially across the aperture, the coupling arrangement comprising a first coupling element configured to excite a first electrical field and a second coupling element configured to excite a second electrical field, a first antenna feed line and a second antenna feed line, the first antenna feed line being connected to the first coupling element, the second antenna feed line being connected to the second coupling element.

This solution allows a larger amount of radio frequency output, from e.g. a mmWave radio frequency integrated circuit (RFIC) to be used within the same radiating structure. Hence, there is a need for a reduced number of radiating structures compared to prior art , freeing up precious space within, e.g., an electronic device housing the antenna element. By using a larger amount of radio frequency output, the antenna element produces higher gain and target radiated power. Furthermore, the need for discrete power splitters, combiners, switches, or any other circuitry taking up space is reduced.

In a possible implementation form of the first aspect, the first electrical field and the second electrical field have equal amplitudes and same or opposite phases, such that the radiation excited by the feed lines and coupling elements couple to the same radiating mode of the antenna.

In a further possible implementation form of the first aspect, the first coupling element and the second coupling element is one of a galvanic coupling and a capacitive coupling.

In a further possible implementation form of the first aspect, the first coupling element and the second coupling element extend consecutively after each other or in parallel across the aperture. The consecutive configuration allows the feed lines to be placed closer to the open end of the cavity, while the parallel configuration improves the impedance matching to lower impedance and benefits from moving the feed lines closer to any of the short-circuiting walls or surfaces.

In a further possible implementation form of the first aspect, the conductive structure comprises a first wall and the aperture comprises a slot extending through the first wall, the slot being delimited by a first closed end edge and side edges extending between the first closed end edge and a second closed or open end, the first coupling element and the second coupling element extending at least partially from a first side edge to a second side edge, allowing an antenna element which is extremely spatially efficient and which requires as few components as possible. In a further possible implementation form of the first aspect, the conductive structure comprises a first wall, a second wall, and a closed end surface connecting the first wall and the second wall, the aperture having an open end and being delimited by the closed end surface and the first wall and the second wall, the first coupling element and the second coupling element extending at least partially between the first wall to the second wall, allowing an antenna element in which the coupling elements are protected from external influence and take advantage of existing structures.

In a further possible implementation form of the first aspect, the first antenna feed line extends adjacent the first wall, the first coupling element extending at least partially between the first wall and the second wall, allowing the first wall to be used as reference ground.

In a further possible implementation form of the first aspect, the second antenna feed line extends adjacent the first wall, the second coupling element extending at least partially between the first wall and the second wall, allowing the first wall to be used as reference ground.

In a further possible implementation form of the first aspect, the antenna element further comprises a ground plane extending within the aperture in parallel with the first wall and the second wall, wherein the first coupling element extends at least partially between the first wall and the ground plane, and the second coupling element extends at least partially between the ground plane and the second wall.

In a further possible implementation form of the first aspect, at least one of the first wall and the ground plane is a reference ground.

In a further possible implementation form of the first aspect, the first antenna feed line and the second antenna feed line extend closer to the first wall than to the second wall.

In a further possible implementation form of the first aspect, the first antenna feed line and the second antenna feed line extend closer to the ground plane than to the first wall and to the second wall. In a further possible implementation form of the first aspect, the first antenna feed line extends closer to the first wall than to the ground plane, and the second antenna feed line extends closer to the ground plane than to the second wall.

In a further possible implementation form of the first aspect, the first antenna feed line extends adjacent a first surface of the ground plane or extends adjacent the first wall, and the second antenna feed line extends adjacent an opposite, second surface of the ground plane, allowing the feed lines to use the same reference ground.

In a further possible implementation form of the first aspect, at least one of the first antenna feed line and the second antenna feed line extend outside of the aperture, and the first coupling element and the second coupling element extend through the first wall and/or the second wall by means of throughgoing vias.

In a further possible implementation form of the first aspect, the antenna element further comprises a third antenna feed line and a fourth antenna feed line, the first antenna feed line and the third antenna feed line extending adjacent a first surface of the ground plane or extending adjacent the first wall, and the second antenna feed line and the fourth antenna feed line extending adjacent an opposite, second surface of the ground plane or extending adjacent the second wall, allowing additional electric fields to be generated.

In a further possible implementation form of the first aspect, the first antenna feed line is connected to the first coupling element such that the first coupling element extends between the first antenna feed line and the second antenna feed line, and the third antenna feed line is connected to the second coupling element such that the second coupling element extends between the third antenna feed line and the fourth antenna feed line.

In a further possible implementation form of the first aspect, the first coupling element comprises first sub-coupling elements and the second coupling element comprises second sub coupling elements, one of the first sub-coupling elements and one of the second sub-coupling elements extending between the first wall and the ground plane, one of the first sub-coupling elements and one of the second sub-coupling elements extending between the ground plane and the second wall, the first antenna feed line being connected to one first sub-coupling element, the second antenna feed line being connected to a further first sub-coupling element, the third antenna feed line being connected to one second sub-coupling element, the fourth antenna feed line being connected to a further second sub-coupling element, allowing the antenna element to be configured as efficiently yet as spatially efficient as possible.

According to a second aspect, there is provided an electronic device comprising a display, a housing, and any least one antenna element according to the above, wherein at least part of the conductive structure of the antenna element is at least one of a mechanical structure and a solid or flexible printed circuit board. This solution allows a larger amount of radiofrequency output, from e.g. a mmWave radio frequency integrated circuit (RFIC) to be used within one radiating structure, which radiating structure may be comprised within other already existing device components.

In a possible implementation form of the second aspect, the housing comprises a back cover and a conductive frame extending between peripheral edges of the display and the back cover, the display being separated from the conductive frame by means of a dielectric gap, the antenna element extending adjacent a face of the display, and the dielectric gap allowing the first electrical field and/or the second electrical field excited by the antenna element to radiate past the conductive frame, taking advantage of the existing configuration of electronic devices without having to add artificial gaps merely for the sake of antenna radiation.

In a further possible implementation form of the second aspect, the electronic device comprises a plurality of antenna elements forming an antenna array, the antenna elements of the antenna array sharing at least one of the first wall, the second wall, or a third wall extending between the first wall and the second wall of the antenna elements, allowing an improved antenna which comprises as many antenna elements as possible.

This and other aspects will be apparent from and the embodiments described below.

BRIEF DESCRIPTION OF THE DRAWINGS

In the following detailed portion of the present disclosure, the aspects, embodiments and implementations will be explained in more detail with reference to the example embodiments shown in the drawings, in which: Fig. 1 shows perspective views of an electronic device in accordance with one embodiment of the present invention;

Fig. 2 shows a perspective view of an antenna element in accordance with one embodiment of the present invention;

Fig. 3 shows a perspective view of an antenna element in accordance with one embodiment of the present invention;

Fig. 4 shows a perspective view of an antenna element in accordance with one embodiment of the present invention;

Fig. 5 shows a perspective view of an antenna element in accordance with one embodiment of the present invention;

Fig. 6 shows a perspective view of an antenna array in accordance with one embodiment of the present invention;

Fig. 7 shows a perspective view of an antenna element in accordance with one embodiment of the present invention;

Fig. 8 shows a perspective view of an antenna element in accordance with one embodiment of the present invention;

Fig. 9 shows a perspective view of an antenna element in accordance with one embodiment of the present invention;

Fig. 10 shows a perspective view of an antenna element in accordance with one embodiment of the present invention;

Fig. 11 shows a perspective view of an antenna array in accordance with one embodiment of the present invention. DETAILED DESCRIPTION

Fig. 1 shows schematic perspective views of an electronic device 11 comprising a display 12, a housing 13, and any least one antenna element 1 which is described in more detail below. The antenna element 1 extends adjacent a face of the display 12. The housing 13 comprises a back cover 13a and a conductive frame 13b extending between peripheral edges of the display 12 and the back cover 13 a. The display 12 is separated from the conductive frame 13b by means of a dielectric gap which allows a first electrical field and/or a second electrical field, excited by the antenna element 1, to radiate past the conductive frame 13b. At least a part of a conductive structure 2 of the antenna element 1 may be comprised in a mechanical structure and/or a solid or flexible printed circuit board of the electronic device 11.

Figs. 2 to 5 and 7 to 10 show different embodiments of the antenna element 1. The antenna element 1 comprises a conductive structure 2 comprising an aperture 3, as well as a coupling arrangement extending at least partially across the aperture 3. The coupling arrangement comprises a first coupling element 4 configured to excite a first electrical field and a second coupling element 7 configured to excite a second electrical field. In one embodiment, the first electrical field and the second electrical field have equal amplitudes and same or opposite phases. This is to ensure that the radiation excited by the pair of coupling elements couple to the same radiating mode of the same antenna.

The antenna element 1 furthermore comprises at least one first antenna feed line 5 and at least one second antenna feed line 6. The first antenna feed line 5 is connected to the first coupling element 4, and the second antenna feed line 6 is connected to the second coupling element 7.

As shown in Fig. 10, the conductive structure 2 may comprise a first wall 2a, such as a plate. The aperture 3 comprises a slot 9 extending through the first wall 2a. The slot 9 may be delimited by a first closed end edge 9a and side edges 9c, 9d extending between the first closed end edge 9a and an opposite, second closed end 9b. The slot 9 may also be delimited by the first closed end edge 9a and the side edges 9c, 9d, while having an open end 9b opposite to the first closed edge 9a (not shown). The first coupling element 4 and the second coupling element 7 extend partially, or completely, from a first side edge 9c to a second side edge 9d, i.e. essentially in parallel with the first wall 2a. The first coupling element 4 and the second coupling element 7 may be capacitive couplings, as shown in Fig. 10, or galvanic (not shown). The antenna element 1 may comprise a plurality of first antenna feed lines 5 and/or second antenna feed lines 6 with corresponding first coupling elements 4 and second coupling elements 7.

The electronic device 11 may comprise a plurality of antenna elements 1 forming an antenna array 16. The antenna elements 1 of the antenna array 16 may have one shared first wall 2a, comprising a plurality of apertures 3 as shown in Fig. 11.

The antenna array 16 allows a high number of radiofrequency outputs, e.g. 8-16, to be used by means of a plurality of feed lines arranged within one radiating structure. This reduces the need for discrete power splitters or combiners or switches, or any other circuitry taking up space. Each antenna element 1 of the antenna array 16 comprises two or more feed lines, the phasing and placement of which is configured such that they couple to the same radiating mode of the antenna. The phase angles may be offset between antenna elements 1 , allowing phased beam steering. In one embodiment, the polarity of one of the signals is reversed.

As shown in Figs. 2 to 5 and 7 to 9, the conductive structure 2 may comprise a first wall 2a and a second wall 2b, preferably extending in parallel, and a closed end surface 2c connecting the first wall 2a and the second wall 2b, preferably extending perpendicular to the first wall 2a and the second wall 2b. The conductive structure 2 may also comprise a third wall 2e extending between the first wall 2a and the second wall 2b, preferably extending perpendicular to the first wall 2a, the second wall 2b, and the closed end surface 2c. The conductive structure 2 may also comprise a fourth wall 2f (not shown) extending between the first wall 2a and the second wall 2b, preferably extending parallel with the third wall 2e. Hence, the first wall 2a, the second wall 2b, the closed end surface 2c, the third wall 2e, and the fourth wall 2f substantially form an open-ended cavity. The cavity, i.e. the aperture 3, has an open end 2d and is delimited by, at least, the first wall 2a, the second wall 2b, and the closed end surface 2c. The first coupling element 4 and the second coupling element 7 extend at least partially between the first wall 2a and the second wall 2b, which is described in more detail below. The first coupling element 4 and the second coupling element 7 may be one of a galvanic coupling, as indicated in Fig. 2, and a capacitive coupling, as indicated in Fig. 3.

The electronic device 11 may comprise a plurality of antenna elements 1 forming an antenna array 16. The antenna elements 1 of the antenna array 16 may share at least one of the first wall 2a, the second wall 2b, or the third wall 2e extending between the first wall 2a and the second wall 2b of the antenna elements 1. The antenna elements 1 may also share the closed end surface 2c. As shown in Fig. 6, all antenna elements 1 may share the same first wall 2a and second wall 2b, while every pair of adjacent antenna elements 1 share one wall between them, this wall comprising at least one of the third wall 2e and the fourth wall 2f.

The first coupling element 4 and the second coupling element 7 may be arranged such that they extend consecutively after each other across the aperture 3, i.e. in series, as shown in Figs. 4, 5, and 9, or in parallel across the aperture 3, as shown in Figs 2, 3, and 7 to 10. The consecutive/series configuration allows the feed lines to be placed closer to the open end of the cavity. The parallel configuration improves the impedance matching to lower impedance and benefits from moving the feed lines closer to any of the short-circuiting walls or surfaces 2a, 2b, 2c, 2e.

As shown in Figs. 2, 3, 5, and 7 to 9 the first antenna feed line 5 may extend adjacent the first wall 2a, the first coupling element 4 extending at least partially between the first wall 2a and the second wall 2b. The first wall 2a may be a reference ground for first antenna feed line 5.

As shown in Figs. 2, 3, and 7 to 9 the second antenna feed line 6 may also extend adjacent the first wall 2a, the second coupling element 7 extending at least partially between the first wall 2a and the second wall 2b. The first wall 2a may be a reference ground for second antenna feed line 6.

As shown in Figs. 4, 5, and 9, the antenna element 1 may also comprise a ground plane 10 which extends within the aperture 3, in parallel with the first wall 2a and the second wall 2b. The first coupling element 4 extends at least partially between the first wall 2a and the ground plane 10, and the second coupling element 7 extends at least partially between the ground plane 10 and the second wall 2b.

The first antenna feed line 5 and the second antenna feed line 6 may extend closer to the first wall 2a than to the second wall 2b, as shown in Figs. 2 to 5 and 7 to 9, such that the first wall 2a is the reference ground.

The first antenna feed line 5 and the second antenna feed line 6 may also extend closer to the ground plane 10 than to the first wall 2a and to the second wall 2b, as shown in Fig. 4. In this embodiment, the ground plane 10 is the reference ground for first antenna feed line 5 as well as second antenna feed line 6.

As shown in Fig. 5, the first antenna feed line 5 may extend closer to the first wall 2a than to the ground plane 10, while the second antenna feed line 6 extends closer to the ground plane 10 than to the second wall 2b.

The second antenna feed line 6 may extend adjacent a second surface of the ground plane 10, as shown in Figs. 4 and 5, while the first antenna feed line 5 extends adjacent an opposite first surface of the ground plane 10 as show in in Fig. 4, or adjacent the first wall 2a as shown in Fig. 5.

As shown in Fig. 8, at least one of the first antenna feed line 5 and the second antenna feed line 6 may extend outside of the aperture 3, i.e. on side of the first wall 2a and/or the second wall 2b which does not face the aperture space. The first coupling element 4 and the second coupling element 7 extend through the first wall 2a and/or the second wall 2b by means of throughgoing vias, i.e. vertical interconnect access openings, (not shown), such that they reach and at least partially extend across the aperture 3.

As shown in Figs. 7 to 9, the antenna element 1 may comprise a third antenna feed line 14 and a fourth antenna feed line 15. The third antenna feed line 14 is similar, preferably identical, to the first feed line 5, and the fourth antenna feed line 15 is similar, preferably identical to the second feed line 6.

The first antenna feed line 5 and the third antenna feed line 14 extend adjacent a first surface of the ground plane 10 (not shown), or adjacent the first wall 2a. The second antenna feed line 6 and the fourth antenna feed line 15 extend adjacent a second surface of the ground plane 10, as shown in Fig. 9, or adjacent the second wall 2b, as shown in Figs. 7 and 8.

The first antenna feed line 5 is connected to the first coupling element 4 such that the first coupling element 4 extends between the first antenna feed line 5 and the second antenna feed line 6. The third antenna feed line 14 is connected to the second coupling element 7 such that the second coupling element 7 extends between the third antenna feed line 14 and the fourth antenna feed line 15. The first coupling element 4 may comprise first sub-coupling elements 4a, 4b and the second coupling element 7 may comprise second sub-coupling elements 7a, 7b, as shown in Fig. 9. A first sub-coupling element 4a and a second sub-coupling element 7a may extend between the first wall 2a and the ground plane 10. A further first sub-coupling element 4b and a further second sub-coupling element 7b may extend between the ground plane 10 and the second wall 2b. The first antenna feed line 5 is connected to the first sub-coupling element 4a, and the second antenna feed line 6 is connected to the further sub-coupling element 4b. The third antenna feed line 14 is connected to the second sub-coupling element 7a, and the fourth antenna feed line 15 is connected to the further second sub-coupling element 7b.

The third antenna feed line 14 may, just as the first antenna feed line 5, extend adjacent the first wall 2a, the second coupling element 7 extending in parallel with the first coupling element 4 and at least partially between the first wall 2a and the second wall 2b. The first wall 2a may be a reference ground for third antenna feed line 14. The third antenna feed line 14 may extend closer to the first wall 2a than to the second wall 2b, as shown in Figs. 7 to 9, such that the first wall 2a is the reference ground. The third antenna feed line 14 may also extend closer to the ground plane 10 than to the first wall 2a (not shown). In such an embodiment, the ground plane 10 is the reference ground for the third antenna feed line 14. The fourth antenna feed line 15 may extend closer to the ground plane 10 than to the second wall 2b. The fourth antenna feed line 15 may extend adjacent a second surface of the ground plane 10 while the third antenna feed line 14 extends adjacent an opposite first surface of the ground plane 10 or adjacent the first wall 2a (not shown).

The various aspects and implementations have been described in conjunction with various embodiments herein. However, other variations to the disclosed embodiments can be understood and effected by those skilled in the art in practicing the claimed subject-matter, from a study of the drawings, the disclosure, and the appended claims. In the claims, the word “comprising” does not exclude other elements or steps, and the indefinite article “a” or “an” does not exclude a plurality. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measured cannot be used to advantage.

The reference signs used in the claims shall not be construed as limiting the scope.