Dual-polarized radiating assembly

ES 2 245 441 T3

DESCRIPTION

Radiant dual polarization configuration.

The invention relates to an arrangement of dual polarization antenna elements, especially for the field of mobile radio transmission according to the preamble of claim 1.

Dual polarization antenna elements are preferably used in the field of mobile radio transmission at a frequency of 800 to 1000 MHz and 1700 to 2200 MHz. In this case, one antenna generates two orthogonal polarizations, especially the efficiency has proven of the use of two linear polarizations with the orientation of + 45 ° or -45 ° with respect to the vertical (polarization X). To optimize the illumination of the supply area, antennas with different average horizontal widths are used, with average widths of 65 ° and 90 ° having been imposed as a useful scale.

For antennas with only one polarization there are several solutions according to the state of the art to realize these different average widths.

Thus, for example simple vertically oriented dipoles with a reflector optimized to the corresponding mean width are used as vertically polarized antennas. For antennas with only one operating frequency range, solutions for X-polarized antennas with average widths of 90 ° have already been disclosed. For this, for example cross dipoles or square dipoles or patch antenna elements with a correspondingly configured reflector are used to achieve a corresponding horizontal mean width.

According to DE-A1-197 22 742, a reflector geometry is proposed for this purpose in which grooves are applied at the lateral limits of the reflector which protrude laterally relative to the reflector plate. If such a reflector geometry is used, for example with cross dipoles or with a special dipole structure, as is known, for example, from DE 198 60 121 A1, then a horizontal mean width can be realized between approximately 85 ° and 90 °. However, this example refers only to an antenna that operates only in one operating frequency band.

However, in the case of dual-polarized antenna elements, which must operate in two frequency ranges that are arranged separately from each other, that are arranged offset from each other, for example by a factor of 2: 1, solutions are known with only average horizontal widths of approximately 65 °.

Thus, for example, according to document US-B-6 333 720 (corresponding to document DE-A1-198 23 749) an antenna is proposed in the form of a square of dipoles that is composed of four dipoles that are arranged displaced with respect to each other and oriented in each case in parallel in pairs. In this case each dipole is made up of two dipole halves that are fed centered by means of a balancing circuit. The respective dipole halves are fed in this case at their mutually directed ends at feed points which are configured at least approximately equiphasic and approximately symmetrically there. In the corner areas of the dipole square, the dipole ends that are displaced 90 ° relative to each other are isolated from each other with respect to the high frequency.

Additionally, in this previous publication a combination of dipole antenna elements is proposed by means of which an average width of approximately 65 ° can be realized for the two frequency ranges (for example, the 900 MHz band and the 1800 band). MHz).

For example, a corresponding solution using patch antenna elements is known from WO 00/01 032.

The realization of antennas that can operate in two frequency bands or in two operating frequency ranges and also must have an average width of approximately 90 ° has not been possible up to now.

Furthermore, reference is also made to other previous antennas publications which, however, are also not suitable in an average width of about 90 ° for operation in two frequency ranges arranged offset from one another. In this case, they are, for example, antennas as described in the publication S. Maxi and Bifi Gentili: "Dual-Frequency Patch Antennas" in: IEEE Antennas and Propagation Magazine, volume 39, no. 6, December 1997. A dual-polarized antenna that has a triple structure and is oriented horizontally and vertically in its polarization can also be detached as known in Nobuhiro Kuga: “A Notch-Wire Composite Antenne for Polarization Diversity Reception” in IEEE AP volume 46, no. 6, June 1998, pages 902-906. This antenna generates an omnidirectional pattern. But neither can any dual-band antenna with an average horizontal width of about 90 ° be able to follow from this.

Therefore, the aim of the invention is to create an arrangement of antenna elements that, on the one hand, can be used for two orthogonal polarizations, and in which at least one antenna element can be integrated in a higher frequency range, being able to realize medium widths of approximately 90 °.

The object is achieved according to the invention according to the characteristics indicated in claim 1. Advantageous embodiments of the invention are indicated in the dependent claims.

Thanks to the arrangement of dual-polarization antenna elements according to the invention, the possibility is first created of constructing antennas that have horizontal mean widths of 90 ° in the two frequency ranges. Regardless of this, these antenna element structures can also be used to operate, if necessary, only in one frequency range.

The invention is shown below by means of drawings. In this case they show in particular:

Figure 1, a schematic perspective representation of an arrangement of dual polarization antenna elements according to the invention, Figure 2, a schematic side view of the arrangement of antenna elements shown in perspective representation in Figure 1 in a section perpendicular cross-section through the plane of the reflector, FIG. 3, a schematic plan view of the embodiment according to FIGS. 1 and 2,

ES 2 245 441 T3 FIG. 4, a schematic representation in perspective of a modified embodiment of an arrangement of antenna elements, FIG. 5, a side view of the embodiment according to FIG. 4, FIG. 6, a view In plan of the embodiment according to Figures 4 and 5, Figure 7, a plan view corresponding to Figure 6 of a modified embodiment with a pattern of holes as antenna element arrangements, FIG. 8, a plan view of another modified embodiment with convexly formed antenna element arrangements, FIG. 9, another modified embodiment in a schematic plan view with concavely formed antenna element arrangements, FIG. Figure 10, a schematic plan view of another modified embodiment with extensions of lateral antenna elements, Figure 11, a plan view of a variant of the exemplary embodiment shown in figure 10 with projecting projections running perpendicular to the elongation extensions, figure 12, a side view of the exemplary embodiment according to figure 11, figure 13, a view a schematic plan of an arrangement of antenna elements in two double polarization bands with a patch antenna element that is arranged inside for the highest frequency, figure 14, a perspective representation of the antenna element arrangement according to figure 13, figure 15, a schematic plan view of an antenna element arrangement modified with respect to figure 13, and figure 16, a schematic perspective representation with respect to the exemplary embodiment of figure 15.

Figures 1 to 3 show a first embodiment of a dual polarization antenna according to the invention.

As can be seen from Figure 1 in perspective representation, from Figure 2 in a schematic side view (in a perpendicular sectional representation through the plane of the reflector) and from Figure 3 in a plan view, the arrangement of elements of The antenna according to the invention has essentially four antenna element devices 1, that is to say four antenna element devices 1a, 1b, 1c and 1d, which are conductive. These four antenna element devices 1 form a square-shaped structure in plan view. In other words, the antenna is formed with the described antenna element arrangement with point symmetry or 90 ° rotation symmetry in plan view.

The antenna element devices 1 that form a square structure in plan view can also be called antenna elements, antenna arms, antenna rods or, in general, antenna structures.

These four rod-shaped antenna element devices 1 in the exemplary embodiment shown according to FIGS. 1 to 3, have approximately a length equal to approximately 0.2 times to 1 times the operating wavelength λ. The separation from plane 3 of reflector 5 is approximately 1/8 to 1/4 of the operating wavelength.

From the structure described, it is obtained, therefore, that in the exemplary embodiment shown rod-shaped antenna element devices 1 are arranged which are arranged parallel to the plane of the reflector in a common plane 7 of antenna elements. In this case the antenna devices 1 facing each other, that is to say, in the embodiment shown, the antenna element devices 1a and 1c are arranged parallel to each other. Furthermore, the two additional antenna element devices which are arranged in each case offset by 90 °, that is to say, in the illustrated embodiment, the antenna element devices 1b and 1d, are also arranged parallel to each other. The two pairs of antenna element devices arranged parallel to each other, 1a and 1c on the one hand and 1b and 1d on the other hand, are oriented perpendicular to each other or at least approximately perpendicular to each other, thereby an arrangement of antenna elements is produced that can emit and receive in two polarizations that are perpendicular to each other, and specifically in a plane E1 that is oriented at an angle of + 45 ° with respect to the horizontal and in a plane E2 that is oriented at an angle of -45 ° with respect to the horizontal.

As can also be seen from the exemplary embodiment, the two ends 9 of the four antenna element devices 1 facing each other, that is to say, spaced from each other, namely the ends 9a, 9a 'and 9b, 9b', as well as 9c, 9c 'and 9d, 9d' of antenna elements are isolated against high frequency with respect to the adjacent end point in each case of the device of adjacent antenna elements. That is, the end 9a of the antenna element is isolated against the high frequency of the end 9b 'of the adjacent antenna element, the end 9b of the antenna element is isolated from the end 9c' of the adjacent antenna element, the end 9c of the antenna element of the end 9d 'of the adjacent antenna element and the end 9d of the antenna element of the end 9a' of the adjacent antenna element. Each of the four antenna element devices 1 is clamped and supported in each case by means of an electrically conductive clamping device 17, preferably relative to the reflector 5. In the exemplary embodiment according to FIGS. 1 to 3, this holding device 17 can be composed, by device 1 of antenna elements, of two rods or device 19 of rods that are guided in each case from a base 21 preferably formed by the reflector, in which they are mechanically mounted and positioned as conductors of electricity, to the antenna element devices 1 divergent towards the antenna element ends 9. In this case, the arrangement is such that the rod devices 19 are led in each case towards the ends of adjacent antenna elements, for example, to the antenna element ends 9a and 9b 'of the devices 1a and 1b of antenna elements arranged adjacent to each other run parallel from their base 21 with a spacing from each other, whereby a slot or gap 25 is formed in each case between two rods or two rod devices 19 arranged adjacently.

ES 2 245 441 T3

From the described structure it can be seen, on the one hand, that the rods or rod device 19, at the end 27 on the reflector side or on the base side, are connected to each other by means of a conductive base 21, the conductive plate 5 of the reflector and / or a conductive connection 29. As stated, a cable connection to the reflector 5 is additionally preferably also produced in this case. However, this cable joint does not necessarily have to be present.

Approximately, in the exemplary embodiment described according to FIGS. 1 to 3, by means of the corresponding antenna element device 1, the clamping device 17, 19 or rods leading to the ends of the corresponding antenna elements of the antenna element. antenna elements and ends 27 that are arranged on the base or reflector side, as well as by means, if applicable, of the conductive connection devices 29 provided in the middle and / or a conductive base or by means of the reflector 5 itself a trapezoidal structure is formed.

The supply of the antenna element devices 1 is carried out in this embodiment at the corresponding end of the four gaps or slots 25, that is to say, at the antenna element ends 9. The supply is in this case carried out at these four corners or points 13 preferably by means of coaxial cables 31 which are indicated schematically in the schematic plan view according to FIG. 2.

In this case, the inner conductor 31 'is electrically connected in each case to one of the ends of one of the antenna element devices 1 and the outer conductor 31' 'to the adjacent end of the adjacent antenna device 1. In other words, for example, the outer connector 31 "of the coaxial cable 31 is electrically connected to the end 9a of the antenna element of the antenna element device 1a, while the inner conductor 31 'is electrically connected to the end 9b' of the adjacent antenna element of the adjacent antenna element device 1b.

Therefore, at the ends 9 arranged in pairs adjacent to each other of the antenna element devices 1, that is to say, at the four mentioned points or corners 13 feeding points 113 are formed in each case, so that the supply of the The antenna element arrangement is carried out in each case in an equiphasic manner at these feed points, that is to say, at the opposite end to the reflector side of the grooves or interstices 25 at the diametrically opposite points or corners in each case, that is, at the corresponding end of the gap at the mentioned feed points 113. This can be done, for example, through interconnection using a coaxial cable of equal length from a central feed point. Thus, two central power points 35a and 35b are originated for each of the orthogonal polarizations which at the same time present a high decoupling from each other.

Since the rods or rod device 19 of the clamping device 17 and thus the grooves or gaps 25 have a length λ / 4, the antenna element ends 9 can be short-circuited without problems on the base or reflector side. Therefore, in this example, they act in conjunction with the power cables as balanced.

In the schematic cross-sectional representation according to FIG. 2, the reflector is shown in cross-section, which may also comprise on the outside lateral limitation walls 5 'which run transverse or perpendicular to the plane 3 of the reflector.

In the following, reference is made to a following exemplary embodiment.

By means of Figures 4 and 5 another embodiment is shown. This embodiment differs from that according to Figures 1 to 3 in that the surface, which is surrounded by the corresponding antenna element device 1 and the rods or rod devices 19 acting laterally at the ends of the element devices 1 antenna and by the base 21 that supports the rods 19 and, if applicable, by the reflector 5 and / or the conductive connection elements 29 mentioned, it is not free or empty, Rather, it is electrically shaped over the entire surface and is thus designed as a closed surface. Thus, four antenna element devices 1 or antenna element structures 1 are thus created, each having a closed surface element 39. In each case, the upper limit edge 1 'of this surface element 39 represents the antenna element device 1 which can be compared with the exemplary embodiment according to FIGS. 1 to 3. Finally, the lateral limit edges 19 'represent the rods or rod device 19 that delimit the corresponding slot or the corresponding gap 25. The lower edge 27 'can be compared to the connecting element 28 on the base or reflector side.

Another difference between the exemplary embodiment according to FIGS. 4 to 6 and the exemplary embodiment according to FIGS. 1 to 3 is that the surface elements 39 in the representation in vertical section are configured on the edge, the lower section 39 ', on the the base or the reflector, the surface element runs slightly divergent outwards (for example, at an angle of 20 ° to 70 °, preferably 30 ° to 60 °, especially 45 °), while only a section 39 ", which is arranged outwards and is separated from the reflector, of the corresponding surface element 39 is oriented in the vertical direction, that is, perpendicular to the reflector.

5. This opens the possibility that the total length of the groove or gap 25, and thus the total length of the limit edges 19 'comparable to the clamping rods 19' according to figure 1, is again λ / 4 of the operating frequency (preferably the medium operating frequency), in such a way that by means of the surface elements 39 a short circuit of the boundary edges 19 'of antenna elements that are arranged above and run parallel to the reflector can take place on the base or reflector side, by which the true antenna element devices 1. The exemplary embodiment according to FIG. 2 also shows that of course the exemplary embodiment according to FIG. 1 should not run with rods or rod devices 19 running straight, but also, in the exemplary embodiment according to FIG. 1 a 3, the rods or rod devices, which run parallel to each other, may have a bent shape, comparable to the edge 19 'in the exemplary embodiment according to FIGS. 3 and 5, forming a groove 25.

ES 2 245 441 T3

The overall height of an antenna element formed in this way is less due to this bent configuration of the individual surface elements 39.

The embodiment according to FIGS. 4 to 6 can also be configured in such a way that only rectangular surface elements 39 "are provided which are arranged above, instead of the lower surface elements 39 'configured in the plan view in the form of trapezium in each case, interruptions are provided, the upper surface elements 39 "then being held by means of lateral support elements 19.

The schematic plan view according to FIG. 7 only shows that the surface elements 39, in contrast to the last mentioned embodiment, do not have to be designed closed over the entire surface, but can also, for example, be provided of a pattern 43 of holes. Other deviations are also possible and conceivable.

In the exemplary embodiment according to FIG. 8, a global structure has been selected in which the individual antenna element devices 1 are not formed by rods or boundary edges running straight, but rather form devices 1 of convex or convex antenna elements. partially circular in plan view. If the crosswise-facing grooves or interstices 25 were not limited by clamping rods or rod devices 19, but rather these edges 19 'were part of surface elements 39 which are arranged offset by 90 °, then these would be configured in the same way. corresponding so that they would run aligned in the form of a partial truncated cone or partial cylinder.

In an exemplary embodiment according to FIG. 9, the antenna element devices 1 are not convex, but concave. Likewise, in this exemplary embodiment, the device 1 of antenna elements arranged above again could be configured as a device in the form of an electrically conductive rod or the like, which are held by means of rods or corresponding rod devices 19. The intermediate free surface can also be completely closed again, so that the surface elements 39 are formed in a manner comparable to the exemplary embodiment according to FIGS. 4 and 5.

In particular, by means of Figures 8 and 9 it can therefore be seen that the antenna element devices 1, 2, for example, when using corresponding surface elements 39 which may have antenna element edges 1 'which do not only run straight between the feed points 13, 113, but are formed in plan view, considered from a central section, such that they protrude convexly outwardly or even concavely formed. In this case, correspondingly molded antenna element devices 1 or antenna elements 1 can be used which cover the entire surface or part of the surface with surface sections 39 or by forming a corresponding free space 39 '.

In addition, FIG. 10 makes it clear that an improvement in the emission characteristic can also be realized because in the antenna element devices 1, optionally rod-shaped, or in the case of the surface elements 39, at the edges 1 'corresponding boundary that form the true 1 antenna element devices, electrically conductively bonded flaps or extensions 45 may protrude that protrude outwardly running aligned preferably centrally and parallel to the reflector.

In the exemplary embodiment according to FIGS. 11 and 12, another extension 49 is provided at the outer ends of these flaps or extensions 45, which in this exemplary embodiment is preferably vertically aligned with respect to plane 3 of the reflector. In this case, the plan view according to figure 11 also shows that the flaps or extensions 45 that are arranged in each case in pairs offset by 90 ° from each other and preferably run parallel to plane 3 of the reflector can run with different longitudinal extension along the along the plane of the reflector. The same also applies to the elongation extensions 49 that are preferably vertical to the plane 3 of the reflector.

By means of the exemplary embodiments explained, therefore, a dual polarization antenna has been described, that is to say, an arrangement of antenna elements that works in a frequency band and can also have large mean widths of, for example, 90 °.

In this case, for example, several of these antenna element arrangements, explained by means of FIGS. 1 to 11, may be arranged one above the other in a vertical arrangement, preferably in front of a common reflector 3. If the devices 1 antenna elements or boundary edges 1 'are arranged, corresponding to the exemplary embodiments explained, horizontally or vertically with respect to each other, then an X-polarization antenna is thereby obtained in which one of the polarizations is oriented at + 45 ° and the other polarization, at -45 ° with respect to the horizontal plane. Therefore, the polarization directions coincide in plan view with the path of the grooves or interstices 25.

However, in an enlarged antenna structure an overall antenna arrangement can be formed which is also suitable for operation in two frequency bands or ranges which are arranged at a distance from each other and differ, for example, by a factor of 2: 1. In other words, therefore, an antenna can be formed that can be operated in a frequency band of 900 MHz and a frequency band of 1800 MHz or, for example, in a frequency band of 900 Mhz and a frequency band of 2000 Mhz or 2100 MHz.

By means of the embodiment according to FIGS. 13 and 14, this is done because within the arrangement of dual polarization antenna elements explained by FIGS. 1 to 11, another arrangement of antenna elements is provided to operate in a strip of higher frequencies.

In the exemplary embodiment according to Figures 13 and 14 this is done by means of a patch antenna 51 which in the plan view has, for example, a parallelepiped-shaped structure and can also be arranged approximately at the height of the boundary edges 1 ' hence of the antenna element devices 1.

In the exemplary embodiment according to FIGS. 15 and 16, an arrangement 53 of dipoles is used for operation in the highest frequency band.

ES 2 245 441 T3 vector, as is known basically from DE 198 60 121 A1. In this element 53 of vector dipoles, the halves of the dipole, from the structural point of view, are formed in each case by two half-components of the dipole aligned perpendicular to each other, the connection of the ends of the symmetrical or fundamentally symmetrical or approximately symmetrical cables leading to the corresponding dipole halves takes place in such a way that always the corresponding cable halves of the adjoining dipole halves perpendicular to each other are electrically connected. The power supply of the dipole halves arranged diametrically in each case takes place for a first polarization and for a second polarization orthogonal to this in a decoupled manner. The antenna element that is arranged inside, shown in figures 15 and 16, in the form of a vector dipole 53 mentioned is also suitable for sending or receiving X-aligned polarizations, that is, polarizations aligned at + 45 ° or -45 ° with respect to aligned polarizations. In other words, the polarizations of the vector dipole 53 that is arranged inside and the outer antenna element configured in a wedge shape from bottom to top are parallel.

Of course, in contrast to the exemplary embodiments explained so far, other combinations of types of antenna elements, for example cross dipoles, can also be envisaged, which can be used and used within the meaning of the invention.