WO2003075404A1

WO2003075404A1 - Antenna array with a planar dipole

Info

Publication number: WO2003075404A1
Application number: PCT/EP2003/001739
Authority: WO
Inventors: Gerald Schillmeier; Werner Blaier; Udo Flinner; Ralf Exler
Original assignee: Kathrein-Werke Kg
Priority date: 2002-03-07
Filing date: 2003-02-20
Publication date: 2003-09-12
Also published as: AU2003212256A1; ATE323955T1; ES2260611T3; DE10209977A1; EP1481445B1; TWI288987B; EP1481445A1; TW200304250A; DE50303032D1

Abstract

Disclosed is an improved antenna array which is characterized by the fact that at least one coupling element (21, 121) is configured and/or arranged such that the bordering edge (21") of said coupling element (21, 121) is disposed parallel, at least approximately parallel, or at a slightly divergent angle (a) of less than 5 DEG to the corresponding lateral bordering edge (17) of the two dipole halves (1') and that the distance between the bordering edge (21") of the coupling element (21) and the corresponding lateral bordering edge (17) is shorter than 5 mm at least along 50 percent of the total length thereof.

Description

Antenna arrangement with an area dipole

The invention relates to an antenna arrangement with an area dipole according to the preamble of claim 1.

Dipole antennas are well known. They can be used to receive a wide variety of frequencies. The length of the dipole halves depends on the frequency range to be transmitted.

In this context, area dipoles are known in principle, the dipole halves of which consist, for example, of two rectangular conductive dipole halves, which can also be formed, for example, on a substrate in the form of a printed circuit board.

Such area dipoles can also be used, for example, in the DVB-T area.

Such surface dipoles, on the one hand, have a quality that is not sufficient for many applications and / or, above all, an insufficient broadband capability, above all when they should be realized in a comparatively compact design in relation to the operating wavelength.

It is therefore an object of the present invention to provide an antenna arrangement with an area dipole, which has an improved quality and / or broadband capability, in particular with a compact design.

The object is achieved according to the features specified in claim 1 and / or 8. Advantageous embodiments of the invention are specified in the subclaims.

It is more than surprising that an improvement in the quality and / or broadband nature of the area dipole antenna can already be achieved by providing an additional coupling element. This coupling element consists of a conductive, preferably flat arrangement, which is arranged such that it extends with a partial length next to the one dipole half and with a further partial length along the other dipole half. It is preferably provided that the boundary line or edge of the flat coupling element, which is closer to the corresponding lateral boundary lines or edges of the dipole halves of the surface dipole, are directly adjacent to one another.

In a particularly preferred embodiment of the invention it is provided that the adjacent boundary lines or edges of the coupling element and the dipole halves of the surface dipole run parallel to one another. In plan view perpendicular to the plane of the surface It is preferably provided that the adjacent boundary edges of the coupling element and the dipole halves lie directly one above the other or are only arranged with a slight or minimal lateral offset to one another.

A particularly favorable implementation can be realized if the coupling element is arranged on one side of a substrate, preferably in the form of a printed circuit board, and the dipole halves of the surface dipole are arranged on the other side of the substrate. Regardless, however, the coupling element can be on the same side of the substrate or the printed circuit board, i.e. if necessary also be provided at the same level. It can also be provided on the substrate spacer or other device in order to arrange the coupling element, if necessary, on another height plane parallel to the plane of extent of the dipole halves of the surface dipole. A small height offset, for example on the order of 0.2 to 4 mm, enables favorable results. Distances of up to 10 mm and more are also possible.

Finally, even more favorable values result if the dipole halves are provided at their ends pointing away from one another with so-called roof capacities which are oriented transversely to the direction of extension of the dipole halves, i.e. electrical sections belonging to the dipole halves and which run transversely to the longitudinal extent of the dipole halves.

In an alternative or, preferably, in a further development of the invention, it is further provided that the dipole halves point outwards from their middle section to be facing each other to their opposite Sections become increasingly wider at least in a partial longitudinal direction, that is to say become wider in their plane of extension. The lateral boundary edges of the dipole halves can preferably run diverging from the center to their outer end, as a result of which a further improvement in the broadband range can be achieved with the simplest implementation of the area dipole. Because the boundary edges of the coupling element preferably run parallel to the boundary edges of the adjacent dipole halves of the surface dipole (or are arranged only diverging at a small angle to one another), these boundary edges of the coupling element can also run obliquely.

Finally, a further improvement can also be realized in that a further coupling element is provided opposite the coupling element on the other adjacent side of the dipole halves. This further coupling element can furthermore also comprise a matching network which can be implemented with the printed circuit board and the coupling element on a microstrip basis. This further coupling element is preferably formed in the longitudinal direction of the dipole halves with a smaller longitudinal extension than the opposite coupling element mentioned first.

Both coupling elements can also be electrically (eg capacitively) or galvanically connected. The adaptation network or parts thereof can also be provided on both coupling elements. The radiation characteristic of the antenna can also be influenced by means of the two or the at least one coupling element. The invention is explained in more detail below with reference to drawings. The following show in detail:

FIG. 1: shows a schematic plan view of a first exemplary embodiment of an antenna arrangement with an area dipole and a lateral coupling element;

Figure 2 is a cross-sectional view along the

Longitude plane in Figure 1;

3 shows a further cross-sectional illustration through the exemplary embodiment according to FIG. 1, but along a cross-sectional plane transverse to the longitudinal direction L in FIG. 1;

FIG. 4: an embodiment example modified from FIG. 1 in plan view with dipole halves widening outward in a wedge shape;

FIG. 5: an exemplary embodiment, modified from FIG. 4, in a top view with respect to a surface dipole with a correspondingly adapted coupling element;

FIG. 6: a further modified exemplary embodiment with an adaptation network; and

FIG. 7: an exemplary embodiment modified again compared to FIG. 6. FIG. 1 shows a schematic plan view of a first exemplary embodiment of an antenna arrangement according to the invention in the form of a flat dipole 1 with two dipole halves 1 ′ which extend in the longitudinal direction 3.

For this purpose, the surface dipole 1 comprises conductive surface elements 5 for the dipole halves 1 ', which can preferably be formed on a substrate 7, in particular in the form of a printed circuit board 7'.

According to the exemplary embodiment according to FIGS. 1 and 2, the actual dipole halves 1 'are rectangular and have a length L and a width B in the plane of extension E of the dipole halves 1'.

At the two mutually facing, inner ends 9 of the dipole halves 1 ', a feed point 11 is provided for the feed.

In the exemplary embodiment shown, so-called roof capacitances 1 ″ are formed on the opposite, ie outer ends 13 of the dipole halves l ¹ to improve the broadband capability and / or to improve the quality of the antenna, which in the exemplary embodiment shown also have a rectangular structure and run at right angles to the longitudinal extent 3 of the area dipole 1. The protrusions 16 of the roof capacities 1 ", that is, the extent to which the roof capacities 1" protrude beyond the side delimitation edges 17 of the dipole halves 1 ', can be selected differently for optimization. In the exemplary embodiment shown, these protrusions 16 are smaller than the longitudinal dimension of the dipole halves 1 'without the roof capacities 1 ". On the other hand, there would be an extent in the transverse direction to the longitudinal direction of the surface dipole 1, which corresponds to greater than 10%, preferably greater than 20%, in the exemplary embodiment shown approximately 40% to 60% of the longitudinal extent of a dipole half 1 '. In the exemplary embodiment shown, the width of the roof capacities 1 "is smaller than the width of the dipole halves 1 'and is preferably approximately 30% to 70%, preferably 40% to 60% of the width of the dipole halves 1'. However, the widths can also be of the same order of magnitude lie.

To improve the quality and / or broadband nature of the antenna, a coupling element 21 is now provided, which in the exemplary embodiment shown consists of a conductive surface element 21 '. In the exemplary embodiment shown according to FIGS. 1 and 2, this conductive surface element 21 'is formed on the opposite side 25 of the printed circuit board 7'. Therefore, in the top view according to FIG. 1, the coupling element lying on the underside of the printed circuit board 7, 7 'is shown in broken lines. The coupling element 21 is rectangular in plan view and is arranged such that its longitudinal extension extends parallel to the longitudinal direction 3 of the surface dipole 1. Its boundary edge 21 "runs parallel to the side boundary edges 17 of the dipole halves 1 'parallel and preferably in plan view transversely to the plane of extent E congruent with the side boundary edges 17 or only with a slight lateral offset of preferably less than 20 mm, in particular less than 10.5 or even The distance between the at least one coupling element and the respectively adjacent dipole half can be chosen to be larger the longer the roof capacities are. Instead of the parallel alignment of the boundary edge 21 ″ of the coupling element 21 with the adjacent side boundary edges 17 of the dipole halves 1 ′, a slightly divergent angle of preferably less than 5 °, in particular less than 1 °, can also be set between the boundary edges. A parallel course of the edges to one another However, in the case of non-linear boundary edges of the dipole halves and the coupling element, it is preferably provided that the distance between the adjacent edges remains the same or preferably changes only slightly, ie the change in distance between the adjacent edges the dipole halves and the coupling element should preferably not be more than 10%, in particular not more than 5% or at least not more than 1% of the operating wavelength over the length of the dipole halves, ie at least over half the length of the dipole halves.

The improved quality and broadband are also produced in that the plane E _{κ of} the coupling element 21 is offset from the plane of extension E _{D of} the surface dipole 1, namely in the exemplary embodiment shown at a distance corresponding to the thickness D of the substrate 7. The thickness of the substrate can be adjusted by suitable means Material selection, that is, can be additionally changed by the respective dielectric constant. However, additional structures can also be provided in order to make the distance between the extension plane E _{κ of} the coupling element 21 and the dipole halves 1 ′ even larger, that is to say deviating from the thickness of the substrate 7. Likewise, the coupling element 21 can be on the same side like the surface dipole 1, and is only by a minimal dimension nated gap of preferably less than 5mm, in particular less than 1mm to the adjacent side boundary edge 17 of the dipole halves 1 'separated. In the same way, spacer elements can also be provided on the same side of the substrate, so that the coupling element 21 can be arranged in a plane offset from the plane of the dipole halves 1 '.

If the coupling element is arranged on a different side or on a different height level than the dipole halves, the coupling element and the dipole halves can also be arranged in an overlapping manner in plan view. The overlap can extend over a certain length and / or the entire width of the dipole.

The exemplary embodiments 1 and 2 also show that the coupling element 21 is preferably arranged symmetrically to a transverse plane of symmetry 27, that is to say extends with the same partial length parallel to both dipole halves 1 '.

Reference is now made to an exemplary embodiment according to FIG. 4, in which an improvement in the antenna properties, in particular with regard to their broadband capability, is achieved by using no rectangular dipole halves 1 'but flat dipole halves 1', the side boundary edges 17 of which lie from their inner end 9 become increasingly wider towards their outer end 13, at least in a partial longitudinal extension of the dipole halves 1 '. In the exemplary embodiment shown according to FIG. 4, these dipole halves 1 'are designed to become continuously wider from the inside to their outer end, so that their side boundary edges 17 from diverging from the inside to the outside. The angle at which the side boundary edges 17 diverge with respect to each dipole half 1 'can be, for example, around 30 °. Values from 10 ° to 50 °, in particular 20 ° to 40 °, are preferably used. This results in a triangular or trapezoidal structure for the dipole halves 1 'from above. The roof capacities 1 ″ are again preferably present at the outer end and may then only protrude laterally to a lesser extent from the outer broad end of the dipole halves 1 ′.

A further improvement, in particular the quality of the adaptation, is realized in the exemplary embodiment according to FIG. 5 in that the coupling element 21, already explained with reference to FIGS. 1 ff, is provided on at least one side of the two dipole halves 1 ', which is on the same side in the same or is provided or formed for this purpose in a staggered plane or on the opposite side of the substrate on the boundary plane of the substrate or in a plane staggered thereto. Since the boundary edge 21 ″ of the coupling element 21 adjacent to the side boundary edge 17 of the respective dipole half 1 ′ should preferably run parallel or with a constant distance or only diverging at a small angle or with a variable distance from one another, the plan view according to FIG. 4 then preferably results In this exemplary embodiment, the coupling element 21 is at least approximately roof-shaped or gable-shaped in a side view along the arrow representation 29.

In the embodiment according to FIG. 6, the embodiment according to FIG. 5 is now supplementary A further coupling element 121 is provided on the opposite side to the coupling element 21. A coupling element 21 or a further coupling element 121 is thus provided on both sides in plan view transversely to the plane of extent E of the substrate and thus to the plane of extent of the dipoles. This further coupling element 121 preferably further comprises an adaptation network 31, which can also be implemented on a microstrip basis with the substrate 7 of the printed circuit board 7 'and the coupling element. In the exemplary embodiment according to FIG. 5, the connecting lines 33 to the matching network 31 and from there the feed lines 35 to the feed point 11 are also drawn in at the inner ends 9 of the two dipole halves 1 '. This adaptation network 31 can also include devices for balancing.

The further coupling element 121 has only a smaller longitudinal extent in the longitudinal direction 3 than the first coupling element 21 in order to improve the adaptation.

According to the exemplary embodiment according to FIG. 5, the additional coupling elements 21, 121 can be provided on the same side of the substrate 7 as the surface dipoles 1 '. However, both coupling elements 21, 121 can also be provided on the opposite side 25, that is to say on the opposite side of the substrate in relation to the surface dipoles 1 '. Finally, however, a coupling element 21 or 121 can also be provided on the side of the substrate on which the surface dipoles 1 'are also provided, whereas the other coupling element 121 or 21 is arranged on the opposite side 25. Whenever the coupling elements on the same side and possibly on the same extension plane as that Surface dipoles 1 "are provided, preferably at least one slightly dimensioned gap 41 is provided between the boundary edge 21" of the coupling element 21 or 121 and the boundary edge 17 of the corresponding surface dipole 1 '.

The two coupling elements can also be electrically (e.g. capacitively) or galvanically connected, e.g. via a connection which is provided in the spacing space between the two inner ends of the dipole halves and / or via one or more bridge connections across the dipole halves. The matching network or parts thereof can also be provided on the second coupling element or on both coupling elements.

Figure 7 shows in principle the same embodiment as Figure 6, but with the difference that to adapt to lower frequencies without extending the area used, the dipole halves 1 'are arranged asymmetrically with or without their coupling elements to their roof capacities 14, so that the Overhangs 16 of the roof capacity at the respective outer ends of the two dipole halves 1 'project at different distances transversely to the longitudinal direction of the dipole halves 1'.

For the sake of completeness, it is pointed out that the antenna can also be designed without a substrate. The antenna arrangement is then, for example, using dipole halves and using at least one coupling element, which can be milled or stamped, for example, from sheet metal, preferably via spacers to form the antenna arrangement explained. adds.

Claims

claims:

1. Antenna arrangement with an area dipole (1), which is preferably arranged on a substrate (7), in particular in the form of a printed circuit board (7 ¹ ), with or without and on the outer ends (13) of the dipole halves (1 ') roof capacities (14) extending transversely to the longitudinal direction (3) of the dipole halves (1 '), characterized by the following features a) at least one coupling element (21, 121) is provided, b) the coupling element (21, 121) formed and / or arranged so that the boundary edge (21 ") of this coupling element (21, 121) to the adjacent one

Side boundary edge (17) of the two dipole halves

(l ¹ ) at least over half the length of one

Dipole half (l ¹ ), but preferably over the entire

Length of the dipole halves - parallel or at the same distance less than 5 mm, or

- runs at least approximately parallel, or

- diverging at an angle () of less than 10 °, or - runs with a changing distance, the change in distance not exceeding 10% of the operating wavelength.

2. Antenna arrangement according to claim 1, characterized in that the coupling element (21) extends at least with approximately the same partial length next to both dipole halves (1 ').

3. Antenna arrangement according to claim 1 or 2, characterized in that the coupling element (21) consists of a conductive surface element (21 ').

4. Antenna arrangement according to one of claims 1 to 3, characterized in that the boundary edge (21 ") of the coupling element (21) at a distance of less than 3 mm, in particular less than 2 mm, preferably less than 1 mm to the each adjacent side boundary edge (17) of the associated dipole half (! ').

5. Antenna arrangement according to one of claims 1 to 4, characterized in that the coupling element (21) is arranged in a plane (E _κ ) offset to the extension plane (E) of the surface dipole (1).

6. Antenna arrangement according to claim 5, characterized in that the dipole halves (l ¹ ) are arranged on one side of the substrate (7) and that the at least one coupling element (21) on the opposite side (25) of the substrate (7) is arranged.

7. Antenna arrangement according to claim 5 or 6, characterized in that spacers are provided, about what the distance between the extension plane (E) of the surface dipole (1) to the plane (E _κ ) can be preselected differently.

8. Antenna arrangement with a dipole (1), which is preferably arranged on a substrate (7), in particular in the form of a printed circuit board (7 ¹ ), with or without on the outer ends (13) of the dipole halves (1 ') and transversely to the longitudinal direction (3) of the dipole halves (l ¹ ) extending roof capacities (1 "), in particular according to one of claims 1 to 7, characterized in that the dipole halves (1 ') at least in a partial length between their inner and their outer End '(9, 13) have an increasingly greater width (B) lying transversely to the longitudinal direction (3) in the extension plane (E).

9. Antenna arrangement according to claim 8, characterized in that the dipole halves (l ¹ ) from their inner to their outer end (9, 13) are provided with diverging side boundary edges (17).

10. Antenna arrangement according to claim 8 or 9, characterized in that the dipole halves (1 ') have at least approximately triangular or trapezoidal shape in plan view.

11. Antenna arrangement according to one of claims 1 to 10, characterized in that the boundary edges (21 ") of the coupling element (21) extending at an angle to each other

Have sections which are preferably parallel or at least approximately parallel or at an angle (α) of less than 3 °, preferably at least over half the length of the dipole halves or generally with a changing distance of not more than 5% of the operating wavelength from the adjacent side boundary edges (17) of the respective dipole half (l ¹ ), which are at an angle to the longitudinal direction (3) of the surface dipole (1 ) are provided.

12. Antenna arrangement according to one of claims 1 to 11, characterized in that at least one further coupling element (121) is provided which is formed on the side of the dipole halves (l ¹ ) opposite the first coupling element (21).

13. Antenna arrangement according to one of claims 1 to 11, characterized in that the further coupling element

(121) is provided on the same side (25) of the substrate (7) on which the first coupling element (21) is also arranged or formed.

14. Antenna arrangement according to claim 12 or 13, characterized in that the further coupling element (121) with an adaptation network (31) is preferably also provided in microstrip technology.

15. Antenna arrangement according to claim 13 or 14, characterized in that the matching network (31) or parts thereof are arranged on both coupling elements (21, 121).

16. Antenna arrangement according to one of claims 13 to 15, characterized in that the two coupling elements (21, 121) are electrically, ie in particular capacitively or galvanically connected to one another, preferably Via a connection which lies between the inner ends of the dipole halves (1 ') to be pointed towards one another and / or via at least one or more bridge connections across the dipole halves (1').

17. Antenna arrangement according to one of claims 12 to 16, characterized in that the further coupling element (121) in the longitudinal direction (3) of the surface dipole (1) is dimensioned shorter than the first coupling element (21).

18. Antenna arrangement according to one of claims 1 to 17, characterized in that roof capacitances (1 ") are formed at the outer end of the dipole halves (1 ').

19. Antenna arrangement according to claim 18, characterized in that the roof capacitances (1 ") are formed with their lateral projections so that they extend on both sides of the dipole halves (l ¹ ) transversely to their longitudinal direction (3) with the same spacing.

20. Antenna arrangement according to claim 18, characterized in that the roof capacitances (1 ") are formed with their lateral projections so that they extend on both sides of the dipole halves (l ¹ ) transversely to their longitudinal direction (3) with different spacing dimensions ,

21. Antenna arrangement according to one of claims 1 to 20, characterized in that the dipole halves (l ¹ ) and the optionally provided roof capacities (1 ") and the at least one coupling element (21, 121) directly and / or with the interposition of spacers on one Substrate (7) are preferably arranged in the form of a printed circuit board (7 ').

22. Antenna arrangement according to one of claims 1 to 20, characterized in that the dipole halves (l ¹ ) and the roof capacities (14) which may be provided and the at least one coupling element (21, 121) are constructed in the form of discrete components using spacers, the dipole halves (1) optionally being provided with provided roof capacities (1 ") and preferably the at least one coupling element (21, 121) made of stamped parts.