Patent Description:
With the deployment of <NUM>th generation (<NUM>) mobile networks, new frequency bands of <NUM> and <NUM>, respectively, are introduced. Therefore, there is a growing demand in the market to develop new antenna devices, which support an increased number of bands. For instance, the new antenna devices should support two or more of the following frequency bands: <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, and <NUM>. In addition, in order to fully exploit the capabilities of New Radio (NR) / <NUM> standards, the number of radio channels, antenna ports, and antenna columns per frequency band should also be increased for the new antenna devices.

However, despite this desire to increase the number of frequency bands and antenna ports per band, the limitation of one antenna devices per sector (or at maximum two antenna devices per sector, in exceptional cases) is still a rather strict requirement. In addition, to facilitate antenna site acquisition and/or to be able to reuse current mechanical support structures already installed at the antenna sites, the form factor and the wind-load of the new antenna devices should be comparable to that of legacy products. That is, the new antenna devices should not require additional boxes and should also not require bigger boxes at the antenna sites than the currently installed conventional antenna devices.

This leads to an increased complexity and thus to challenges in designing the new antenna devices. In particular, any new technology or antenna device concept, which enables the integration of several frequency bands together in a neat (compact) and efficient way, becomes really valuable.

<CIT> discloses a base station antenna that integrates a phase shifter and a radiation boundary. <CIT> discloses a multi-layer feed-board with all the functional components, including phase shifters, diplexers, and dipole element, employed thereon. <CIT> discloses a communication system with an ordered arrangement or array of two sets, groups, or groups of antenna elements, where the system can transmit or receive two bands or ranges of electromagnetic energy, signals, or radiation. <CIT> discloses a two-dimensional array of cavity backed slot antenna elements fed via feeding lines partially formed on a side wall of a respective cavity.

In view of the above-mentioned challenges, embodiments of the invention aim to provide a new multi-band antenna device. An objective thereby is to provide an antenna element, which enables building the new multi-band antenna device, without increasing a form factor or wind-load of the new antenna device compared to a legacy (i.e., conventional) antenna device. For instance, a goal is to provide a dual-band antenna element, which includes in a single part at least a part of each antenna array of radiating elements (i.e., an array for each frequency band) and both feeding networks for each array. Line crossings between the feeding networks should be avoided. The antenna element, and accordingly the new antenna device, should further be less complex than a comparable conventional antenna device, for instance, should not require the use of multi-layer PCB structures for forming the feeding networks. In addition, the antenna element and new antenna device should fulfill requirements of the next generations of base station antennas.

The objective is achieved by the embodiments of the invention as described in the enclosed independent claims. Advantageous implementations of the embodiments of the invention are further defined in the dependent claims.

In particular, embodiments of the invention address the multi-band integration problem by using a dielectric body with one or more metal layers, for example, a metallized plastic body. Metallized plastic structures are used in other technical fields to create complex 3D structures, thereby reducing the number of parts and interconnections. For instance, the use of metallize plastic structures is explored for handset devices and automotive. Some approaches also use metallized plastic for base station antennas. However, for base station antennas the technology is more challenging to use, mainly because of the type of radiating elements and the requirements on size and levels of intermodulation.

A first aspect of the present disclosure provides an antenna element for a multi-band antenna device as defined in appended claim <NUM>, the antenna element comprising: a dielectric body provided with metal layers, the dielectric body comprising a base plate and one or more wall elements arranged on the base plate; one or more first radiating elements arranged on the base plate, each first radiating element being configured to radiate in a first frequency band; one or more second radiating elements arranged on the base plate, each second radiating element being configured to radiate in a second frequency band; a first feeding network connected to the one or more first radiating elements, for operating the one or more first radiating elements as a first antenna array; and a second feeding network connected to the one or more second radiating elements, for operating the one or more second radiating elements as a second antenna array; wherein the first feeding network is provided, at least partly, as a metal layer of the one or more metal layers on the one or more wall elements.

The antenna element of the first aspect, by being provided with the dielectric body and at least one metal layer arranged on the one or more wall elements to form the first feeding network, allows integrating both feeding networks in a more limited space. Thereby, the use of multilayer structures and/or line crossing can be avoided, when forming the two feeding networks. Compared to conventional antenna devices, no additional Printed Circuit Boards (PCBs) are required to distribute the respective Radio Frequency (RF) signals to the radiating elements of the different antenna arrays, since all parts of the feeding networks can be implemented in one component.

The one or more wall elements arranged on the base plate is formed integrally with the base plate and/or protrude from the base plate. Further, the first frequency band and the second frequency band may be overlapping or non-overlapping frequency bands. In an implementation form of the first aspect, the one or more wall elements comprise an outer wall element, which extends along the edges of the base plate, and a part of the first feeding network is provided as a metal layer of the one or more metal layers on the outer wall element.

Thus, the first feeding network can be provided for feeding the first radiating elements of the first antenna array, without any line crossings with the second feeding network.

In an implementation form of the first aspect, the part of the first feeding network is provided as a metal layer of the one or more metal layers on one of the surfaces of the outer wall element, and a ground for the first feeding network is provided as a metal layer of the one or more metal layers on the opposite surface of the outer wall element.

Thus, the space provided by the outer wall element is more efficiently used to provide the first feeding network.

In an implementation form of the first aspect, the outer wall element is configured to conform radiation from the one or more first radiating elements and/or from the one or more second radiating elements.

Thus, the outer wall element may be further used to improve the radiation characteristics of the antenna element, for instance, a directivity of the radiation pattern of the antenna element, as well as the port parameters of the antenna element, for instance, the coupling with adjacent antenna columns arranged side-by-side in the multiband antenna.

In an implementation form of the first aspect, the first feeding network comprises a first feeding element for operating the one or more first radiating elements according to a first polarization, and a second feeding element for operating the one or more first radiating elements according to a second polarization; and the outer wall element comprises a first wall section and a second wall section; and the first feeding element is provided as a metal layer of the one or more metal layers on the first wall section, and the second feeding element is provided as a metal layer of the one or more metal layers on the second wall section.

Thus, the space on the outer wall element may be efficiently used to feed the first radiating elements of the first antenna array.

In an implementation form of the first aspect, the one or more wall elements further comprise one or more inner wall elements, each inner wall element connecting the outer wall element to one of the one or more first radiating elements; and a part of the first feeding network is provided as a metal layer of the one or more metal layers on the inner wall elements.

Accordingly, additional wall elements may be used to provide/form the first feeding network, in particular, to connect the first feeding network to all first radiating elements, also those which are located more centrally in the first array (especially in case of a larger first array comprising, for example, multiple rows and columns of radiating elements). Furthermore, the inner wall elements may be used for additional isolation between the first radiating elements and the second radiating elements, thus improving the radiation characteristics of the antenna element.

In an implementation form of the first aspect, the second feeding network is provided, at least partly, as a metal layer of the one or more metal layers on the base plate.

Thus, the dielectric body is used to form both feeding networks in an efficient manner, i.e., with less space required and without any line crossings or multi-layer structures being necessary.

In an implementation form of the first aspect, the one or more wall elements and the radiating elements are arranged on an upper surface of the base plate; a part of the second feeding network is provided as a metal layer of the one or more metal layers on a lower surface of the base plate; and the base plate is arranged on a reflector plate of the antenna element, the reflector plate serving as ground for the second feeding network.

In an implementation form of the first aspect, the reflector plate is configured to reflect radiation from the one or more first radiating elements and/or from the one or more second radiating into a main radiation direction.

In an implementation form of the first aspect, the one or more wall elements and the radiating elements are arranged on an upper surface of the base plate, the second feeding network is provided as a metal layer of the one or more metal layers on the upper surface of the base; plate; and a ground for the second feeding network is provided as a metal layer of the one or more metal layers on the lower surface of the base plate.

In this way, the base plate of the dielectric body is efficiently used to provide more space for the second feeding network.

In an implementation form of the first aspect, the first feeding network and the second feeding network are arranged without line crossing of feeding lines of the first feeding network and the second feeding network.

In an implementation form of the first aspect, the one or more first radiating elements are one or more low band (LB) radiating elements, and the one or more second radiating elements are one or more high band (HB) radiating elements; or the one or more first radiating elements are one or more HB radiating elements, and the one or more second radiating elements are one or more LB radiating elements.

Accordingly, the antenna element allows fabricating an integrated multi-band antenna device with at least two different frequency bands.

In an implementation form of the first aspect, the first frequency band is lower than the second frequency band; and/or the first frequency band is a frequency range of <NUM>-<NUM>, and the second frequency band is a frequency range of <NUM>-<NUM>.

In an implementation form of the first aspect, the one or more first radiating elements comprise one or more dipole radiating elements; and/or the one or more second radiating elements comprise one or more patch radiating elements.

In an implementation form of the first aspect, the one or more first radiating elements and/or the one or more second radiating elements comprise one or more linear dual-polarized radiating elements.

In an implementation form of the first aspect, the one or more first radiating elements and/or the one or more second radiating elements are formed, at least partly, by the dielectric body.

Thus, the dielectric body of the antenna element has a further purpose, namely forming at least in part the radiating elements. A more compact antenna element, which is also simple to fabricate, is thus possible.

In an implementation form of the first aspect, each of the one or more second radiating elements comprises a first patch formed by the dielectric body, and comprises a second patch stacked onto the first patch.

In this way, the bandwidth of the second antenna array can be increased.

In an implementation form of the first aspect, each of the one or more first radiating element comprises a balun formed by the dielectric body, and comprises a PCB, in which a dipole is formed, the PCB being connected to the balun.

In this way, the molding of the dielectric body and, e.g., metallization thereof, becomes simpler, and production costs can be reduced.

In an implementation form of the first aspect, the second patch and the PCB are formed by a further dielectric body of the antenna element, the further dielectric body being attached to the dielectric body.

In this way, the antenna element can be formed in a simpler manner, and the number of components can be reduced.

A second aspect of the present disclosure provides multi-band antenna device comprising one or more antenna elements, each configured according to the first aspect or any of its implementation forms.

A third aspect of the present disclosure provides a method for producing an antenna element for a multi-band antenna device as defined in appended claim <NUM>, the method comprising: forming a dielectric body comprising a base plate and one or more wall elements arranged on the base plate; forming one or more first radiating elements arranged on the base plate, each first radiating element being configured to radiate in a first frequency band; forming one or more second radiating elements arranged on the base plate, each second radiating element being configured to radiate in a second frequency band; forming a first feeding network connected to the one or more first radiating elements, for operating the one or more first radiating elements as a first antenna array; and forming a second feeding network connected to the one or more second radiating elements, for operating the one or more second radiating elements as a second antenna array; wherein the first feeding network is formed, at least partly, by metallizing the one or more wall elements.

In an implementation form of the third aspect, the one or more wall elements comprise an outer wall element, which extends along the edges of the base plate, and a part of the first feeding network is formed by metallizing the outer wall element.

In an implementation form of the third aspect, the part of the first feeding network is formed by metallizing one of the surfaces of the outer wall element, and a ground for the first feeding network is formed by metallizing the opposite surface of the outer wall element.

In an implementation form of the third aspect, the outer wall element is formed to be configured to conform radiation from the one or more first radiating elements and/or from the one or more second radiating elements.

In an implementation form of the third aspect, the first feeding network comprises a first feeding element for operating the one or more first radiating elements according to a first polarization, and a second feeding element for operating the one or more first radiating elements according to a second polarization; and the outer wall element comprises a first wall section and a second wall section; and the first feeding element is formed by metallizing the first wall section, and the second feeding element is formed by metallizing the second wall section.

In an implementation form of the third aspect, the one or more wall elements further comprise one or more inner wall elements, each inner wall element connecting the outer wall element to one of the one or more first radiating elements; and a part of the first feeding network is formed by metallizing the inner wall elements.

In an implementation form of the third aspect, the second feeding network is formed, at least partly, by metallizing the base plate.

In an implementation form of the third aspect, the one or more wall elements and the radiating elements are arranged on an upper surface of the base plate; a part of the second feeding network is formed by metallizing a lower surface of the base plate; and the base plate is formed on a reflector plate of the antenna element, the reflector plate serving as ground for the second feeding network.

In an implementation form of the third aspect, the reflector plate is configured to reflect radiation from the one or more first radiating elements and/or from the one or more second radiating into a main radiation direction.

In an implementation form of the third aspect, the one or more wall elements and the radiating elements are arranged on an upper surface of the base plate, the second feeding network is formed by metallizing the upper surface of the base; plate; and a ground for the second feeding network is formed by metallizing the lower surface of the base plate.

In an implementation form of the third aspect, the first feeding network and the second feeding network are formed without line crossing of feeding lines of the first feeding network and the second feeding network.

In an implementation form of the third aspect, the one or more first radiating elements are one or more LB radiating elements, and the one or more second radiating elements are one or more HB radiating elements; or the one or more first radiating elements are one or more HB radiating elements, and the one or more second radiating elements are one or more LB radiating elements.

In an implementation form of the third aspect, the first frequency band is lower than the first frequency band; and/or the first frequency band is a frequency range of <NUM>-<NUM>, and the second frequency band is a frequency range of <NUM>-<NUM>.

In an implementation form of the third aspect, the one or more first radiating elements comprise one or more dipole radiating elements; and/or the one or more second radiating elements comprise one or more patch radiating elements.

In an implementation form of the third aspect, the one or more first radiating elements and/or the one or more second radiating elements comprise one or more linear dual-polarized radiating elements.

In an implementation form of the third aspect, the one or more first radiating elements and/or the one or more second radiating elements are formed, at least partly, by the dielectric body.

In an implementation form of the third aspect, each of the one or more second radiating elements comprises a first patch formed by the dielectric body, and comprises a second patch stacked onto the first patch.

In an implementation form of the third aspect, each of the one or more first radiating element comprises a balun formed by the dielectric body, and comprises a PCB, in which a dipole is formed, the PCB being connected to the balun.

In an implementation form of the third aspect, the second patch and the PCB are formed by a further dielectric body of the antenna element, the further dielectric body being attached to the dielectric body.

The method of the third aspect and its implementation forms provides the same advantages as described above for the antenna element of the first aspect. The method of the third aspect results in the fabrication of the antenna element of the first aspect and thus leads to the mentioned advantages. In particular, the antenna element of the first aspect and the multi-band antenna device of the second aspect, respectively, can be easily fabricated using the method of the third aspect.

Even if, in the following description of specific embodiments, a specific functionality or step to be performed by external entities is not reflected in the description of a specific detailed element of that entity which performs that specific step or functionality, it should be clear for a skilled person that these methods and functionalities can be implemented in respective software or hardware elements.

<FIG> shows an antenna element <NUM> according to an embodiment of the invention. The antenna element <NUM> may be used to form a multi-band antenna device, for instance, a dual-band antenna device or a triple-band antenna device. The antenna element <NUM> of <FIG> is exemplarily shown to work in two frequency bands, but it may work in more than two frequency bands.

The antenna element <NUM> comprises a dielectric body <NUM> provided with one or more metal layers. The one or more metal layers may be arranged on the dielectric body <NUM>, particularly on surfaces of the dielectric body <NUM>. However, one or more metal layers could also be provided within the dielectric body <NUM>. Further, the dielectric body may be made of plastic. In particular, the dielectric body may thus be a selectively metallized plastic part. The dielectric body <NUM> comprises a base plate 101a and one or more wall elements 101b, 101c, which are arranged on the base plate 101a. The one or more wall elements 101b, 101c may protrude from the base plate 101a along a z-axis (i.e., an axis normal to the base plate), and may further be formed integrally with the base plate 101a. The one or more wall elements 101b, 101c comprise an outer wall element 101b, for instance, surrounding the base plate 101a, i.e., extending along the edges of the base plate 101a (as shown in <FIG>). Further, the one or more wall elements 101b, 101c comprise one or more inner wall elements 101c, i.e., one or more wall elements 101c that are arranged centrally on the base plate 101a and/or are arranged within the area surrounded by the outer wall element 101b.

Further, the antenna element <NUM> comprises one or more first radiating elements <NUM>, which are arranged on the base plate 101a, for example regularly (e.g., in rows and/or columns) or irregularly, wherein each first radiating element <NUM> is configured to radiate in a first frequency band. The antenna element <NUM> also comprises one or more second radiating elements <NUM> arranged on the base plate 101a, for example regularly (e.g., in rows and/or columns) or irregularly, and/or interleaved with the first radiating elements <NUM>, wherein each second radiating element <NUM> is configured to radiate in a second frequency band. The first frequency band and the second frequency band may be different frequency bands. For instance, the first frequency band may be lower than the second frequency band, or vice versa. The first frequency band and the second frequency band may be overlapping, in particular, partially overlapping, or they may be non-overlapping. For instance, the first frequency band may be a frequency range of <NUM>-<NUM>, and the second frequency band may be a frequency range of <NUM>-<NUM>.

The one or more first radiating elements <NUM> may comprise one or more dipole radiating elements, and/or the one or more second radiating elements <NUM> may comprise one or more patch radiating elements, or vice versa. Thereby, the one or more first radiating elements <NUM> and/or the one or more second radiating elements <NUM> may comprise one or more linear dual-polarized radiating elements. The first radiating elements <NUM> may comprise one or more LB radiating elements, and may thus form an LB antenna array. The second radiating elements <NUM> may comprise one or more HB radiating elements, and may thus form a HB antenna array. Alternatively, the first radiating elements <NUM> may comprise one or more HB radiating elements, and the second radiating elements, <NUM> may comprise one or more LB radiating elements. The one or more first radiating elements <NUM> and/or the one or more second radiating elements <NUM> may be formed, at least partly, by the dielectric body <NUM>, i.e., by one or more metal layers of the dielectric body <NUM>.

The antenna element <NUM> further comprises a first feeding network <NUM> connected to the one or more first radiating elements <NUM>, for operating the one or more first radiating elements <NUM> as a first antenna array. Further, the antenna element <NUM> comprises a second feeding network <NUM> connected to the one or more second radiating elements <NUM>, for operating the one or more second radiating elements <NUM> as a second antenna array. The first feeding network <NUM> and/or the second feeding network <NUM> may comprise one or more feeding lines, in particular, to connect to the respective radiating elements <NUM>/<NUM> fed by the feeding network <NUM>/<NUM>. The first feeding network <NUM> and the second feeding network <NUM> may thereby be arranged without any crossings of respective feeding lines. Neither the first feeding network <NUM> nor the second feeding network <NUM> may further require a multi-layer structure.

In particular, the first feeding network <NUM> is provided, at least partly, as a metal layer of the one or more metal layers on the one or more wall elements 101b, 101c, i.e., is formed by the dielectric body <NUM>. For instance, the first feeding network <NUM> may be provided on the outer wall element 101b and/or on one or more inner wall elements 101c. That is, the first feeding network <NUM> may be integrated into the wall elements 101b, 101c of the dielectric body <NUM> of the antenna element <NUM>. For instance, the one or more wall elements 101b, 101c may have first surfaces wherein the first feeding network <NUM> is provided, particularly as metallization or a metal layer, on the first surfaces. Further, the one or more wall elements 101b, 101c may have second surfaces, which may be used as ground for the feeding network <NUM>, the ground being provided as metallization or a metal layer on the second surfaces. The outer wall element 101b may further serve as an electrical fencing, which is configured to conform the radiation pattern of one or both of the first and second frequency band. That is, the outer wall element 101b may be configured to conform radiation from the one or more first radiating elements <NUM> and/or from the one or more second radiating elements <NUM>.

Also the second feeding network <NUM> may be provided, at least partly, as a metal layer on the dielectric body <NUM>, particularly on the base plate 101a. That is, the second feeding network <NUM> may be integrated into a bottom part of the dielectric body <NUM> of the antenna element <NUM>. It is, however, also possible to provide, at least part of, the second feeding network <NUM> on the one or more wall elements 101b, 101c.

<FIG> show an antenna element <NUM> according to an embodiment of the invention, which builds on the embodiment shown in <FIG>. Same elements in <FIG> and <FIG> are provided with the same reference signs, and may be implemented likewise. In particular, <FIG> shows a top-view of the antenna element <NUM>, <FIG> shows an enlarged top-view of the antenna element <NUM>, <FIG> shows a bottom-view of the antenna element <NUM>, and <FIG> shows an enlarged bottom-view of the antenna element <NUM>.

In particular, in the embodiment of <FIG>, the first radiating elements <NUM> are LB radiating elements and form an LB array, and the second radiating elements <NUM> are HB radiating elements and form a HB array.

As can be seen in <FIG> and <FIG>, the first feeding network <NUM> of the LB radiating elements <NUM> is arranged at least partly on the one or more wall elements 101b, 101c. The first feeding network <NUM> is particularly arranged on the outer wall element 101b of the dielectric body <NUM>. Thereby, one of the polarizations may be arranged in a first wall section of the outer wall element 101b, for instance, the left part of the outer wall element 101b. The other polarization may be arranged in a second wall section of the outer wall element 101b, for instance, the right part of the outer wall element 101b. The inner wall elements 101c of the dielectric body <NUM> may be used to route signals from the LB radiating elements <NUM> (those arranged in the center, particularly arranged between the HB radiating elements <NUM>) to the outer wall element 101b. The first feeding network <NUM> could also be arranged on the inner wall elements 101c of the dielectric body <NUM>.

As can be seen in <FIG> and <FIG>, the second feeding network <NUM> of the HB radiating elements is arranged in the lower surface of the bottom area of the dielectric body <NUM>, i.e., in the base plate 101a. The dielectric body <NUM> is further arranged on top of a reflector plate that serves as ground for the second feeding network <NUM> for the HB array. An implementation, in which the second feeding network <NUM> is arranged on the upper surface of the base plate 101a of the dielectric body <NUM>, and the ground is arranged in the lower surface of the base plate 101a or vice versa (without using any reflector plate) is also possible.

In the embodiment of <FIG>, as an example, the HB is <NUM>-<NUM> and the LB band is <NUM>-<NUM>. The spacing between HB radiation elements <NUM> may be <NUM> in horizontal and <NUM> in vertical, whereas the vertical spacing between the LB radiating elements <NUM> may be <NUM>.

The LB radiating elements may be cross-fed dipoles and the HB radiating elements <NUM> may probe-fed patches. Some or all radiating elements <NUM>/<NUM> may be linear dual-polarized +/- <NUM> slant.

As exemplarily shown in <FIG>, there may be three dipole radiating elements <NUM> working in the LB, and twelve patch radiating elements <NUM> working in the HB. In this particular example, the HB radiating elements <NUM> are clustered into four groups of three dual-polarized radiating elements <NUM> each (best seen in <FIG>), wherein two clusters are on one (long) side of the antenna element <NUM>, and the other two clusters are on the other (long) side of the antenna element <NUM>.

The above-mentioned frequency bands, dimensions and clustering serve only as an example to convey an idea of embodiments of the invention. However, embodiments of the invention can be extended to be used with any other combination of frequency bands, dimensions and clustering. The embodiments of the invention are also not be limited to any specific kind of radiating element(s) <NUM> and <NUM>.

<FIG> shows an antenna element <NUM> according to an embodiment of the invention, which builds on the embodiment shown in <FIG>. Same elements in <FIG> and <FIG> are provided with the same reference signs, and may be implemented likewise. In particular, <FIG> shows that a first part 102a of a first radiating element <NUM> may be formed by the dielectric body <NUM>, and a second part 102b of the first radiating element <NUM> may be implemented as separate part 102b, i.e., as a part 102b that is added onto the dielectric body <NUM>. For example, as shown in <FIG>, a dipole of the first radiating element <NUM> may be implemented in an additional PCB (being the part 102b), which may be soldered to the part 102a, specifically a balun, of the first radiating element <NUM> formed by the dielectric body <NUM>. In particular, each of the one or more first radiating elements <NUM> may comprise a balun 102a formed by the dielectric body <NUM>, and may comprise an additional PCB 102b, in which a dipole is formed, the additional PCB 102b being connected to the balun 102a.

Also a first part 103a of a second radiating element <NUM> may be formed by the dielectric body <NUM>, and a second part 103b of the second radiating element <NUM> may be formed as separate part 103b, i.e., as a part 103b that is added onto the dielectric body <NUM>. For instance, each of the one or more second radiating elements <NUM> may comprise a first part (e.g., patch) 103a formed by the dielectric body <NUM>, and may comprise a second part (e.g., patch) 103b connected to the first part 103a.

In this respect, <FIG> shows that the second parts 102b and 103b of the one or more first radiating elements <NUM> and the one or more second radiating elements <NUM>, respectively, may be formed, at least partly, by a further dielectric body <NUM>. For instance, the second patch 103b and the additional PCB 102b may be formed, respectively, by the further dielectric body <NUM> (e.g., with one or more metal layers) of the antenna element <NUM>. The further dielectric body <NUM> may be attached/connected to the dielectric body <NUM> (shown in the assembled state in <FIG>).

A reason for not including all the components into the dielectric body <NUM> may be, for example, that the presence of the dipole (in <FIG> provided/defined in the additional PCB 102b) would complicate the molding and the etching of the dielectric body <NUM>, and would thus increase production costs. The additional stacked patches 103b may further increase the bandwidth of the second array (e.g., the HB array), and may thus be considered if the bandwidth requirements are not possible to achieve with only one single patch 103a. A good alternative to minimize the number of components would be to merge all the additional parts 102b and 103b (e.g., LB dipole PCB 102b, and HB stacked patches 103b) into the further dielectric body <NUM>, for instance, being another metallized plastic part.

In an embodiment of the invention, HB radiating elements <NUM> may be arranged side-by-side with respect to LB radiating elements <NUM> (see e.g., <FIG>). However, as shown in <FIG>, illustrating an antenna element <NUM> according to an embodiment of the invention, it may also be possible to have them arranged along the same line, e.g., along the length of the antenna element <NUM>.

Further, in an embodiment of the invention, the second feeding network <NUM> may be arranged in the bottom, i.e., the base plate 101a, whereas the first feeding network <NUM> is arranged in the one or more wall elements 101b, 101c, particularly the outer wall element(s) 101b (see e.g., <FIG>). This may be a preferred option when a number of columns of second radiating elements <NUM> is higher than a number of columns of first radiating elements <NUM> (a column being a set of radiating elements <NUM>/<NUM> arranged one after the other on a common axis, wherein the common axis is, in particular, directed across to the length of the base plate 101a, more particularly perpendicular to the length (longer side) of the base plate 101a; similarly a row of radiating elements <NUM>/<NUM> may be perpendicular to a column of radiating elements <NUM>/<NUM>). However, for a situation, in which the number of columns of second radiating elements <NUM> is the same as the number of columns of first radiating elements <NUM>, as in the antenna element of <FIG>, it may be preferable to have the second feeding network <NUM> arranged in the one or more wall elements 101b, 101c, particularly outer wall element(s) 101b, and/or the first feeding network <NUM> in the base plate 101a.

In another embodiment, a third frequency band may be added coexisting in the same dielectric body <NUM>. For instance, <FIG> shows an antenna element <NUM> according to an embodiment of the invention, which builds on the embodiment shown in <FIG>. Same elements in <FIG> and <FIG> are provided with the same reference signs, and may be implemented likewise. In particular, <FIG> shows a triple-band antenna element <NUM>. The antenna element <NUM> comprises one or more third radiating elements <NUM> configured to radiate in a third frequency band (higher than the first or the second frequency band, or lower than the first and the second frequency band, or between the first and the second frequency band). The antenna element <NUM> may also comprise a third feeding network connected to the one or more third radiating elements <NUM>, for operating the one or more third radiating elements <NUM> as a third antenna array. The third feeding network may be formed, at least partly, as a metal layer on the dielectric body <NUM>, for instance, on the one or more wall elements 101b, 101c like the first and second feeding networks <NUM> and <NUM> described above.

Moreover, in other embodiments of the invention, different combinations of HB/LB radiating element columns could be considered. For instance, in <FIG> some examples are depicted. In particular, <FIG> shows an exemplary antenna element <NUM> according to an embodiment of the invention with a 2LB/4HB combination, i.e., LB columns include two LB radiating elements <NUM> and HB columns include four HB radiating elements <NUM>. <FIG> shows an exemplary antenna element <NUM> according to an embodiment of the invention with a 1LB/3HB combination, i.e., LB columns include one LB radiating element <NUM> and HB columns include three HB radiating elements <NUM>. <FIG> shows an exemplary antenna element <NUM> according to an embodiment of the invention with a 1LB/4HB combination, i.e., LB columns include one LB radiating element <NUM> and HB columns include four HB radiating elements <NUM>.

<FIG> shows a method <NUM> according to an embodiment of the invention. The method <NUM> may be used to fabricate the antenna element <NUM> shown in any of the previous figures. The method comprises a step <NUM> of forming a dielectric body <NUM> comprising a base plate 101a and one or more wall elements 101b, 101c arranged on the base plate 101a. Further, the method comprises a step <NUM> of forming one or more first radiating elements <NUM> arranged on the base plate 101a, each first radiating element <NUM> being configured to radiate in a first frequency band, and a step <NUM> of forming one or more second radiating elements <NUM> arranged on the base plate <NUM>, each second radiating element <NUM> being configured to radiate in a second frequency band. Further, the method <NUM> comprises a step <NUM> of forming a first feeding network <NUM> connected to the one or more first radiating elements <NUM>, for operating the one or more first radiating elements as a first antenna array, and a step <NUM> of forming a second feeding network <NUM> connected to the one or more second radiating elements <NUM>, for operating the one or more second radiating elements as a second antenna array. The first feeding network <NUM> is formed, at least partly, by metallizing the one or more wall elements 101b, 101c, in particular, one or more outer wall elements 101b and/or one or more inner wall elements 101c. The second feeding network <NUM> may be formed, at least partly, by metallizing the base plate 101a.

Claim 1:
An antenna element (<NUM>) for a multi-band antenna device, the antenna element (<NUM>) comprising:
a dielectric body (<NUM>) provided with one or more metal layers, the dielectric body (<NUM>) comprising a base plate (101a) and one or more wall elements (101b) arranged on the base plate (101a) and formed integrally with the base plate (101a) and/or protruding from the base plate (101a);
one or more first radiating elements (<NUM>) arranged on the base plate (101a), each first radiating element (<NUM>) being configured to radiate in a first frequency band;
one or more second radiating elements (<NUM>) arranged on the base plate (101a), each second radiating element (<NUM>) being configured to radiate in a second frequency band;
a first feeding network (<NUM>) connected to the one or more first radiating elements (<NUM>), for operating the one or more first radiating elements (<NUM>) as a first antenna array; and
a second feeding network (<NUM>) connected to the one or more second radiating elements (<NUM>), for operating the one or more second radiating elements (<NUM>) as a second antenna array;
wherein the first feeding network (<NUM>) is provided, at least partly, as a metal layer of the one or more metal layers on the one or more wall elements (101b, 101c);
wherein:
the one or more wall elements (101b, 101c) comprise an outer wall element (101b), which extends along the edges of the base plate (101a), and one or more inner wall elements (101c), each inner wall element (101c) connecting the outer wall element (101b) to one of the one or more first radiating elements (<NUM>),
a part of the first feeding network (<NUM>) is provided as a metal layer of the one or more metal layers on the outer wall element (101b), and a part of the first feeding network (<NUM>) is provided as a metal layer of the one or more metal layers on the inner wall elements (101c).