A multi-band antenna with a broadband improved director

Abstract

The disclosure relates to a multi-band antenna with different kinds of radiators. The antenna comprises a reflector, a first radiator and a second radiator arranged on the reflector, and a director. The first radiator is configured to radiate electromagnetic waves in a first frequency band, and the second radiator is configured to radiate electromagnetic waves in a second frequency band that is different from the first frequency band, for instance, is lower than the first frequency band. The director is arranged above the second radiator relative to the reflector, and is configured to be directional for EM waves of the second frequency band. The director comprises a ring-like metal structure and a plurality of metal stubs connected to the ring-like metal structure. The director provides at least low frequency band directivity and broadband transparency.

Description

[0001] A MULTI BAND ANTENNA WITH A BROADBAND IMPROVED DIRECTOR

[0002] TECHNICAL FIELD

[0003] The present disclosure relates to an antenna. For instance, to an antenna for a base station of a mobile communication network. The antenna comprises different kinds of radiators, in order to be operable as a multi-band antenna in different frequency bands. The antenna further comprises a director, which is designed to improve the radiation pattern of the antenna by providing low frequency band directivity and broadband transparency. The director can be directional in the low frequency band and transparent in at least the high frequency band operated by the antenna.

[0004] BACKGROUND

[0005] Network operators are striving for high-efficient antennas, for example, for base stations. A way to improve the cell-efficiency in a network, is to introduce more directive antennas. For instance, this can be achieved by applying a director to the radiators of the antenna. Especially single band antennas are often provided with such a solution. However, an interleaved, multi-band antenna - which comprises low frequency band radiators and high frequency band radiators - is typically not equipped with such directive elements. The reason is that traditional directors would cause resonances and coupling, and therefore would rather deteriorate the radiation pattern of the antenna.

[0006] SUMMARY

[0007] In view of the above, the solutions of this disclosure are based further on the following considerations. To improve the directivity of a multi-band antenna within the low frequency band, an element would be needed that combines two features. Firstly, it should be directive within the low frequency band, and secondly it should be transparent (e.g., non-resonant) within the high frequency band. Conventional solutions do not fulfill both requirements, as they are at least not offering broadband transparency.

[0008] Therefore, an objective of this disclosure is a solution that fulfills both requirements. An objective is, for example, to improve the low frequency band directivity of an antenna without jeopardizing its high frequency band performance. For instance, a broadband frequency range of 1.4-2.7 GHz is thereby targeted. An objective is to provide a director that provides more directivity and more multi-band efficiency to the antenna.

[0009] These and other objectives are achieved by the solutions of this disclosure as described in the independent claims. Advantageous implementations are further described in the dependent claims.

[0010] A first aspect of this disclosure provides an antenna comprising: a reflector; a first radiator arranged on the reflector and configured to radiate electromagnetic (EM) waves in a first frequency band; a second radiator arranged on the reflector and configured to radiate EM waves in a second frequency band that is different from the first frequency band; a director arranged above the second radiator relative to the reflector; wherein the director is configured to be directional for EM waves of the second frequency band; and wherein the director comprises a ring-like metal structure and a plurality of metal stubs connected to the ring-like metal structure.

[0011] The director of the antenna of the first aspect provides more directivity and more multi-band efficiency to the antenna. The antenna may be a multi-band, for example, dual-band antenna. The director improves the low frequency band directivity of the antenna, without negatively impacting the antenna’s high frequency band performance. The ring-like metal structure used for the director allows reducing metal, for example, when compared to a circular metal sheet patch used as director. The metal reduction leads to improved scattering behavior of the director in the high frequency band. The metal stubs, which are electrically connected to the ring-like metal structure, further make the director less resonant in the high frequency band.

[0012] One of the first frequency band and second frequency band is the high frequency band, while the other one is the low frequency band. In the most common example, the first frequency band is the high frequency band, and the second frequency band is the low frequency band.

[0013] A metal stub is a conductive piece, typically in the form of a rod or strip, which may extend straight, but also in a bent of curved manner. A metal stub may be solid or hollow, and may be made of a suitable metal such as copper or aluminum. Each metal stub may have a specific length, shape, and diameter, which may be designed regarding the used frequency bands. The metal stubs may be made of the same material as the ring-like metal structure. The metal stubs and the ring-like metal structure may be integral, formed from a single piece of metal.

[0014] In an implementation form of the first aspect, the director is configured to be non-resonant for EM waves of the first frequency band.

[0015] In an implementation form of the first aspect, the director is configured to be non-resonant for EM waves of the second frequency band.

[0016] Thus, the performance of the antenna of the first aspect can be further improved regarding its transparency. For example, being configured to be directional for EM waves means that the director is designed to focus these EM waves in specific directions, thereby enhancing signal strength in those areas, while minimizing radiation in others. Further, being configured to be non- resonant for EM waves means that the director is designed to not resonate at the frequency of these EM waves, thereby improving its scattering properties and reducing losses regarding these EM waves.

[0017] In an implementation form of the first aspect, each metal stub extends inward or outward from a circumference of the ring-like metal structure.

[0018] In an implementation form of the first aspect, the plurality of metal stubs is distributed around a circumference of the ring-like metal structure, for example, uniformly distributed around the circumference of the ring-like metal structure.

[0019] In an implementation form of the first aspect, the ring-like metal structure comprises a metal ring.

[0020] The metal ring is circular, whereas the ring-like metal structure may deviate from a strictly circular shape. Ring-like metal structure implies, however, that the metal structure forms some sort of closed loop, for instance, defining a circumference.

[0021] In an implementation form of the first aspect, each metal stub extends radially from the metal ring toward the geometric center of the metal ring.

[0022] Radially means regarding the radius of the metal ring. This may be inward or outward of the ring.

[0023] In an implementation form of the first aspect, the plurality of metal stubs is connected together at the geometric center of the metal ring via capacitive coupling. In an implementation form of the first aspect, the ring-like metal structure further comprises a metal patch arranged at the geometric center of the metal ring, the metal patch being disconnected from the plurality of metal stubs.

[0024] The metal patch may be circular. The circular metal patch may be concentrically arranged with the metal ring.

[0025] In an implementation form of the first aspect, the antenna comprises: more than one of the first radiator; more than one of the second radiator; and more than one of the director, wherein each director is associated with one of the second radiators.

[0026] In this way, a larger antenna aperture can be designed, with multiple radiators which may, for example, be arranged in one or more arrays on the reflector.

[0027] For instance, each director may be arranged above one of the second radiators. For example, in this disclosure, one element of the antenna being arranged above another element of the antenna means, that the element is more distant from the reflector than the other element. However, it does not necessarily mean that this element is immediately arranged above the other element (there may be an element in between) or strictly vertically (e.g., perpendicular to the reflector plane) above the other element.

[0028] In an implementation form of the first aspect, the first directors are arranged in a first array, the second radiators are arranged in a second array, and the first array and the second array are arranged in an interleaved manner on the reflector.

[0029] In an implementation form of the first aspect, the directors are arranged on a common substrate layer, and / or on a common dielectric support layer, and / or on a common foil layer.

[0030] This allows ease of fabrication and especially assembly of the antenna of the first aspect.

[0031] In an implementation form of the first aspect, each director is formed by sheet metal or on a printed circuit board.

[0032] This provides a particularly stable implementation, and allows integrating electronic wiring.

[0033] In an implementation form of the first aspect, a radiating element of the second radiator is arranged above a radiating element of the first radiator relative to the reflector.

[0034] In an implementation form of the first aspect, the antenna further comprises an enclosure, wherein the first radiator and the second radiator are both arranged in the enclosure.

[0035] Different radiators or different arrays of radiators can be integrated in the same enclosure, without losing performance due to the solution with the director(s).

[0036] In an implementation form of the first aspect, the first frequency band is higher than the second frequency band.

[0037] Accordingly, the first radiators may be HB radiators, and the second radiators may be LB radiators. The two frequency bands may be separated by a frequency gap.

[0038] In sum, the present disclosure proposes the use of a newly designed director in the antenna of the first aspect, wherein the antenna may be a base station antenna. The newly designed director improves at least the directivity of the EM waves of the second frequency band, that is, it is configured to acts directive for the second radiators. At the same time, the director does not jeopardize the radiation pattern of the first radiators, as it behaves more or less non-resonantly and transparently for the EM waves of the first frequency band.

[0039] BRIEF DESCRIPTION OF DRAWINGS

[0040] The above-described aspects and implementation forms are explained in the following description in relation to the enclosed drawings, in which:

[0041] FIG. 1 shows an antenna according to this disclosure with a first radiator, a second radiator, and a director.

[0042] FIG. 2 shows an exemplary antenna of this disclosure with an array of first radiators, an array of second radiators, and an array of directors.

[0043] FIG. 3 shows an exemplary antenna of this disclosure with an array of first radiators, an array of second radiators, and an array of directors formed on a foil layer.

[0044] FIG. 4 compares scattering characteristics of an antenna with a director as proposed in this disclosure and antennas with simple exemplary directors.

[0045] FIG. 5 compares scattering characteristics of an antenna with a director as proposed in this disclosure and antennas with complex exemplary directors.

[0046] FIG. 6 compares a peak directivity of an antenna with a director as proposed in this disclosure and an antenna with a simple exemplary director.

[0047] FIG. 7 compares a high frequency band pattern of an antenna with a director as proposed in this disclosure and an antenna with a simple exemplary director.

[0048] FIG. 8 compares coupling characteristics for an antenna with a director as proposed in this disclosure and an antenna with a simple exemplary director.

[0049] FIG. 9 illustrates various exemplary implementations of a director as proposed in this disclosure.

[0050] DETAILED DESCRIPTION OF EMBODIMENTS

[0051] FIG. 1 shows an antenna 100 according to this disclosure. The antenna 100 may be suitable for a base station of a mobile communication network. For instance, the antenna 100 may be used in an advanced antenna system (AAS), for example, for a 5G network. The antenna 100 may be suitable for a base station antenna drive system. However, the solutions proposed in this disclosure may be applied to other antennas as well.

[0052] The antenna 100 comprises a reflector 101. For instance, the reflector 101 may be a metal reflector or may have a conductive or metallic surface. The reflector 101 may be designed to reflect or direct EM waves, particularly radio waves. Typically the reflector 101 is arranged behind the radiators of the antenna 100, and reflects all EM waves transmitted by the radiators of the antenna, in order to enhance the antenna's gain and directivity. The reflector 101 may be planar or curved. The radiators of the antenna 100 comprise a first radiator 102 and a second radiator 103. Both radiators 102 and 103 are arranged on the reflector 101. The first radiator 102 is configured to radiate EM waves in a first frequency band, while the second radiator 103 is configured to radiate EM waves in a second frequency band. The second frequency band is different from the first frequency band. For instance, the first frequency band may be higher than the second frequency band, e.g., the first frequency band may be referred to as the high frequency band and the second frequency band may be referred to as the low frequency band. This could, however, be vice versa. The two frequency bands may be non-overlapping. The two frequency bands may be separated by a frequency gap. The two frequency bands may have the same bandwidth or different bandwidth.

[0053] As illustrated in FIG. 1 , just as an example, the two radiators 102 and 103 could be of a different type, and / or different shape, and / or different size. For example, the second radiator 103 may be higher than the first radiators 102, for example, in the sense that a radiating element of the second radiator 103 may be arranged above a radiating element of the first radiator 102 relative to the reflector 101, i.e., regarding a distance from the reflector plane.

[0054] The antenna 100 further comprises a director 104, which is arranged above the second radiator 103 relative to the reflector 101, e.g., regarding a distance from the reflector plane. The director 104 is configured to be directional for EM waves of the second frequency band. That is, the director 104 acts directive for the radiation of the second radiators 103. The director 104 has a specific design that is proposed in this disclosure. Namely, the director 104 comprises a ring-like metal structure 105 and a plurality of metal stubs 106, which are connected to the ring-like metal structure 105, and may extend away from the ring-like metal structure 105. The ring-like metal structure 105 can be a metal ring, but may deviate from a strict ring shape. The metal stubs 106 can be straight as illustrated, but do not have to be. Curved or bent stubs are possible. Further, the stubs 106 may extend toward the inside of the ring-like metal structure 105 as shown, but also could extend toward the outside of the ring-like metal structure 105, or both. Thereby, the metal stubs 106 may extend from a circumference of the ring-like metal structure 105.

[0055] A width and length of the metal stubs 106 can be adjusted, for instance, to optimize for the specifically used frequency bands. Also the number of metal stubs 106 and their arrangement around the circumference of the ring-like metal structure 105 can be adjusted, for instance, for the same purpose. For example, the metai stubs 106 may be uniformly or non-uniformly distributed around the circumference of the ring-like metal structure 105. The design of the director 104 aims at making the director 104 non-resonant for EM waves of the first frequency band. Thus, the director 104 may be made transparent for the radiation of the first radiators 102.

[0056] FIG. 2 shows an exemplary antenna 100 of this disclosure, which bases on the antenna 100 shown in FIG. 1. Same elements in FIG. 1 and FIG. 2 have the same reference signs, and may be implemented likewise. The antenna 100 of FIG. 2 has more than one of the first radiator 102, and more than one of the second radiator 103. All first radiators 102 may be identical, and all second radiators 103 may be identical. For example, as shown in FIG. 2, the antenna 100 may have a first array of first radiators 102, and a second array of second radiators 103. The first array and the second array can be arranged in an interleaved manner on the reflector 101.

[0057] The antenna 100 of FIG. 2 also has more than one director 104, for instance, an array of directors 104. All directors 104 may be identical. Each director 104 is associated with one of the second radiators 103, and may be arranged above that second radiator 103. It may be understood that the antenna 100 of FIG. 1 can constitute a “unit cell”, which is repeated one or more times in the antenna 100 of FIG. 2. The directors 104 in FIG. 2 may be implemented as sheet metal. For the sake of clarity, any supporting plastic components, or the like, are not shown in FIG. 2. FIG. 2 also indicates that the radiating elements 203 of the second radiators 103 are arranged above the radiating elements 202 of the first radiators 102 relative to the reflector 101. The second radiators 103 in FIG. 2 are higher than the first radiators 102, that means, they extend further from the reflector plane.

[0058] FIG. 3 shows another exemplary antenna 100 of this disclosure, which bases on the antenna 100 shown in FIG. 2. Same elements in FIG. 2 and FIG. 3 have the same reference signs, and may be implemented likewise. Also the antenna 100 of FIG. 3 has a plurality of first radiators 102 and a plurality of second radiators 103, which may be arranged in arrays as illustrated, and already described regarding FIG. 2.

[0059] In FIG. 3, the directors 104 of the antenna 100, which are associated one-by-one with the second radiators 103, are formed on a common foil layer 301. For instance, the directors 104 may be patterned on the surface of or in the foil layer 301. Each director 104 may be a metallic or conductive pattern formed on the foil layer 301, for instance, printed on the foil layer 301. The foil layer 301 allows assembling the entire array of directors 104 above the radiator arrays at once. The directors 104 may be pre-patterned or pre-produced on the foil layer 301. The foil layer 301 may be very thin, and thus does not add much weight to the antenna 100. The foil layer 301 may comprise a conductive foil or a dielectric foil, like a plastic foil. For the sake of clarity, any supporting other plastic components of the antenna 100, or the like, are not shown in FIG. 3.

[0060] Alternatively, the directors 104 of the antenna 100 could be formed on a common substrate layer, and / or on a common dielectric support layer. Alternatively, the directors 104 of the antenna 100 could be formed by sheet metal or could be formed on or in a PCB.

[0061] In the following, an antenna 100 of this disclosure with a proposed director 104 is compared with exemplary antennas comprising either simple or complex exemplary directors. In particular, the FIGs. 4 and 5 compare scattering characteristics of various directors, FIG. 6 compares peak directivity of various antennas, FIG. 7 compares a high frequency band pattern of various antennas, and FIG. 8 compares a coupling characteristic for various antennas.

[0062] The solutions of this disclosure, particularly the design of the director(s) 104, are based on two steps of improvement of the director 104. FIG. 4 shows in this regard three different scattering curves of three different directors. Namely, the director 104 of this disclosure, an exemplary circular metal sheet patch director 401, and an exemplary ring director 402. FIG. 4 regards the scattered power within a low frequency band, e.g., the second frequency band 403, and a high frequency band, e.g., the first frequency band 405, which are separated by an unused frequency range 404.

[0063] It can be seen in FIG. 4, that the director 104 of this disclosure is configured to be non-resonant for EM waves of the first frequency band 405 and of the second frequency band 403. For example, a structure like the director 104 can be regarded being non-resonant, if the scattered power is less than a certain value (for instance, less than -50dBi). Furthermore, a structure like the director 104 can be regarded being directive, if the scattered power is higher than a certain value (for instance, higher than -65dBi). Accordingly, the director 104 is also configured to be directional for EM waves of at least the second frequency band 403.

[0064] FIG. 4 shows the scattering behavior of an exemplary circular sheet metal director 401. It can be seen that this director 401 is resonant within the high band frequency band. By reducing metal, for instance, by using an exemplary ring director 402 instead of the exemplary circular metal sheet patch director 401 , the scattering behavior at the higher frequencies can be improved, but not for the entire high frequency band 405. However, with further the metal stubs 106 being added to design the director 104 of this disclosure, wherein the metal stubs 106 are connected electrically to the ring-like metal structure 105 (here specifically a metal ring, like also used for director 402), the director 104 becomes less resonant for the entire high frequency band 405. The correspondent scattering curve shows the improved scattering behavior of the director 104 compared to the directors 401 and 402.

[0065] The number of the metal stubs 106 and / or their lengths may be optimized with the objective of lower scattering within the entire frequency bands 403 and 405, respectively. Thereby, it may be considered that the minimum scattered power within the low frequency band 403 is higher than, for example, the certain value of -65dBi.

[0066] The illustrations of the directors 104 and 402 on the right side of the diagram show also vectors, which indicate the induced maximum current at a high frequency of, e.g., 1.44 GHz. The lengths of the vectors represent the induced electrical current in a linear manner. The current can be reduced by a factor of 4 in the director 104 compared to the director 402 (in the scattering power representation 12 dB), by introducing the plurality of metal stubs 106.

[0067] FIG. 5 compares further scattering curves of two additional exemplary directors 501 and 502, which are more complexly shaped than the exemplary sheet metal patch director 401 and the exemplary ring director 402 in FIG. 4 (the complex shapes of the directors 501 and 502 are illustrated, black being metal, white being cut-outs in the metal). FIG. 5 again regards the scattered power within the low frequency band (here the second frequency band 403) and the high frequency band (here the first frequency band 405), which are separated by an unused frequency range 404. As can be seen in FIG. 5, both exemplary directors 501 and 502 cause higher scattered power values within the high frequency band 405 than the director 104 proposed in this disclosure.

[0068] FIG. 6 shows the peak directivity improvement for the low frequency band radiator (here the second radiator 103), which is achieved by the application of the director 104 in the antenna 100. The result of using the director 104 is shown in comparison to, respectively, the peak directivity 601 of the same second radiator 103 without any director and the peak directivity that is achieved with the exemplary sheet metal patch director 401. For example, the directivity improvement of the sheet metal patch director 401 can be regarded as the maximum achievable directivity improvement.

[0069] FIG. 7 shows a comparison of a high frequency band radiator (here the first radiator 102), reference pattern at 2.3GHz with radiation patterns that result when applying the sheet metal patch director 401 or the director 104 of this disclosure to the low frequency band radiator (here the second radiator 103). The resonant behavior of the sheet metal patch director 401 results in a deteriorated radiation pattern, whereas the radiation patterns 701 of the arrangements without any director, and the one with the non-resonant director 104 are hard to distinguish. In other words, the director 104 of this disclosure does not jeopardize the high frequency band radiation pattern, and therefore behaves “transparently” for the first radiator 102.

[0070] FIG. 9 illustrates various exemplary implementations of the director 104 proposed in this disclosure. Those technical variants of the director 104 may be applied in combination with the above-mentioned implementations of FIG. 1, 2 or 3. Further, any fabrication option of the director 104 described in this disclosure, for instance, formed on a PCB substrate or formed on the foil layer 301, or a sheet metal application etc., is also possible with the shown technical variants of FIG. 9.

[0071] FIG. 9(a) shows an exemplary director 104, which comprises a metal ring as the ring-like metal structure 105 and comprises a plurality of metal stubs 106. A first set of the metal stubs 106 extends inward from the circumference of the metal ring, toward the geometric center of the metal ring, while a second set of the metal stubs 106 extends outward from the circumference of the metal ring. FIG. 9(b) shows an exemplary director 104, which comprises a metal ring as the ring-like metal structure 105 and a plurality of metal stubs 106, which extend inward, and further comprises a metal patch 901 arranged at the geometric center of the metal ring. The metal patch 901 is disconnected from each of the plurality of metal stubs 106.

[0072] FIG. 9(c) shows an exemplary director 104, which comprises a metal ring as the ring-like metal structure 105 and a plurality of metal stubs 106, which extend inward, wherein the plurality of metal stubs 106 is connected together at the geometric center of the metal ring via capacitive coupling 902.

[0073] For example, variations or combinations of the shown directors 104 are possible. For instance, also the directors 104 of FIG. 9(b) and 9(c) may have outward extending metal stubs 106. Further, for each director 104 of FIG. 9, the plurality of metal stubs 106 could also be distributed non-uniformly instead of uniformly around the circumference of the metal ring. Further, each director 104 of FIG. 9 can be implemented with different widths and / or lengths of the metal stubs 106, for instance, to optimize for the specifically used frequency bands. Also the number of the metal stubs 106 can be adjusted in each of the directors 104 of FIG. 9. That is, the directors 104 of FIG. 9 are no limited to the shown number of metal stubs 106, and may include more or less metal stubs 106 than shown.

[0074] In summary, the design of the director 104 presented in this disclosure may make the director 104 non-resonant for EM waves of the first frequency band 405 and the second frequency band 403, and directional at least for the EM waves of the second frequency band 403. In particular, and ultra-broadband transparent director 104 within the high frequency band can be designed, and a directivity improvement within the low frequency band, by at least 0.2dB, can be achieved. Thus, on the one hand side, the present disclosure enables a low-cost directivity improvement for the low frequency band radiators (e.g., the second radiators 103) within an interleaved low and high frequency band (LB-HB) antenna system including also high frequency band radiators (e.g., the first radiators 103). Also, and improvement of the cell-efficiency by more directive antenna elements is possible. The solutions of this disclosure may even be applied to multi-band MIMO arrays.

[0075] The present disclosure has been described in conjunction with various examples as well as implementations. However, other variations can be understood and effected by those persons skilled in the art and practicing the claimed matter, from the studies of the drawings, this disclosure and the independent claims. In the claims as well as in the description the word “comprising” does not exclude other elements or steps and the indefinite article “a” or “an” does not exclude a plurality. A single element or other unit may fulfill the functions of several entities or items recited in the claims. The mere fact that certain measures are recited in the mutual different dependent claims does not indicate that a combination of these measures cannot be used in an advantageous implementation.

Claims

CLAIMS1. An antenna (100) comprising: a reflector (101); a first radiator (102) arranged on the reflector (101) and configured to radiate electromagnetic, EM, waves in a first frequency band (405); a second radiator (103) arranged on the reflector (101) and configured to radiate EM waves in a second frequency band (403) that is different from the first frequency band (405); a director (104) arranged above the second radiator (103) relative to the reflector (101); wherein the director (104) is configured to be directional for EM waves of the second frequency band (403); and wherein the director (104) comprises a ring-like metal structure (105) and a plurality of metal stubs (106) connected to the ring-like metal structure (105).

2. The antenna (100) according to claim 1, wherein the director (104) is configured to be non-resonant for EM waves of the first frequency band (405).

3. The antenna (100) according to claim 1 or 2, wherein the director (104) is configured to be non-resonant for EM waves of the second frequency band (403).

4. The antenna (100) according to one of the claims 1 to 3, wherein each metal stub (106) extends inward or outward from a circumference of the ring-like metal structure (105).

5. The antenna (100) according to one of the claims 1 to 4, wherein the plurality of metal stubs (106) is distributed around a circumference of the ring-like metal structure (105), for example, uniformly distributed around the circumference of the ring-like metal structure (105).

6. The antenna (100) according to one of the claims 1 to 5, wherein the ring-like metal structure (105) comprises a metal ring.

7. The antenna (100) according to claim 6, wherein each metal stub (106) extends radially from the metal ring toward the geometric center of the metal ring.

8. The antenna (100) according to claim 7, wherein the plurality of metal stubs (106) is connected together at the geometric center of the metal ring via capacitive coupling (902).

9. The antenna (100) according to claim 7, wherein the ring-like metal structure (105) further comprises a metal patch (901 ) arranged at the geometric center of the metal ring, the metal patch (901 ) being disconnected from the plurality of metal stubs (106).

10. The antenna (100) according to one of the claims 1 to 9, wherein the antenna comprises: more than one of the first radiator (102); more than one of the second radiator (103); and more than one of the director (104), wherein each director (104) is associated with one of the second radiators (103).

911. The antenna (100) according to claim 10, wherein the first radiators (102) are arranged in a first array, the second directors (103) are arranged in a second array, and the first array and the second array are arranged in an interleaved manner on the reflector (101).

12. The antenna (100) according to claim 10 or 11, wherein the directors (104) are arranged on a common substrate layer, and / or on a common dielectric support layer, and / or on a common foil layer (301).

13. The antenna (100) according to one of the claims 1 to 11, wherein each director (104) is formed by sheetmetal or on a printed circuit board.

14. The antenna (100) according to one of the claims 1 to 13, wherein a radiating element (203) of the second radiator (103) is arranged above a radiating element (202) of the first radiator (102) relative to the reflector (101).

15. The antenna (100) according to one of the claims 1 to 14, further comprising an enclosure, wherein the first radiator (102) and the second radiator (103) are both arranged in the enclosure.

16. The antenna (100) according to one of the claims 1 to 15, wherein the first frequency band (405) is higher than the second frequency band (403).

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