EP4670229A1

EP4670229A1 - SPOTLIGHT, ANTENNA, MOBILE RADIO BASE STATION AND USER DEVICE

Info

Publication number: EP4670229A1
Application number: EP23706755.8A
Authority: EP
Inventors: Sertan HASTÜRKOGLU; Andreas Vollmer; Markus Mohr
Original assignee: Telefonaktiebolaget LM Ericsson AB
Current assignee: Telefonaktiebolaget LM Ericsson AB
Priority date: 2023-02-22
Filing date: 2023-02-22
Publication date: 2025-12-31
Also published as: WO2024175189A1

Abstract

A radiator (18) for an antenna (14) has at least one radiating structure (24) with a conductor (28), the conductor (28) defining a contour (C) of the radiating structure (24) and the conductor (28) having low impedance sections (30) and high impedance sections (32), wherein a total length of the high impedance sections (32) along the contour (C) is longer than a total length of the low impedance sections (30) along the contour (C). Further, an antenna (14, 16), a mobile communication base station (10), and a user device (12) are shown.

Description

Radiator, antenna, mobile communication base station as well as user device

Technical Field

The invention relates to a radiator, an antenna, a mobile communication base station as well as to a user device.

Background

In multiband antennas, radiators or arrays of radiators for at least two different frequency bands are arranged close to one another. It is known to arrange the radiators of different frequency bands one behind the other in the radiation direction of the antenna, wherein the radiators for the higher frequency band are arranged behind the radiators for the lower frequency band.

Often, the radiators of different frequency bands are interleaved, i.e. the radiators overlap with one another. As such, the electromagnetic waves of the mechanically smaller radiators for higher frequencies have to pass the mechanically larger radiators for lower frequencies, which leads to scattering and thus deterioration of signal quality.

In order to improve signal quality, attempts are known, e.g. from US 10 770 803 B2, US 10 439 285 B2 and CN 111864367 A, to increase the transparency of the mechanically larger radiators for frequencies in the second, higher frequency band by arranging conductive segments and inductive segments in an alternating fashion in the radiator.

Further, J. F. Hopf, L. M. Reiter and S. M. Lindenmeier, "Compact multi-antenna system for cars with electrically invisible phone antennas for SDARS frequencies," 2007 2nd International ITG Conference on Antennas, 2007, pp. 171-175, doi: 10.1109/1 NICA.2007.4353956, deals with transparency of antennas.

However, with common solutions the inductive segments are very thin reducing the bandwidth and increasing problems due to variances in the manufacturing process. Further, the total number of segments needed for establishing transparency increases with the highest frequency that the radiator needs to be transparent in.

Summary

Thus, it is an object of the invention to provide a radiator having a transparency for a higher frequency band than its own radiation frequency and which is versatile and reliable to manufacture.

For this purpose, an embodiment relates to a radiator for an antenna, comprising at least one radiating structure with a conductor, the conductor being arranged as to define a contour of the radiating structure and the conductor having low impedance sections and high impedance sections, wherein a total length of the high impedance sections along the contour is longer than a total length of the low impedance sections along the contour.

By choosing low impedance sections and high impedance sections such that the length of the low impedance sections along the contour is shorter than the length of the high impedance sections, very good descattering performance, especially for high frequencies can be achieved with structures that can be manufactured reliably.

The radiator is an electromagnetic radiator. Within this disclosure, the total length of the high and low impedance sections is the sum of the lengths of all high or low impedance sections, respectively.

For example, low impedance sections have an impedance per unit length along the contour being smaller than 1/2, in particular 1/10 of the impedance per unit length along the contour of the high impedance section.

For further improved signal quality, the total length of the high impedance sections along the contour may be at least two times, in particular at least three times longer than the total length of the low impedance sections along the contour.

In an aspect, the low impedance sections and the high impedance sections are arranged in series, improving their performance further.

For example, the low impedance sections and the high impedance sections have an actual length being the length of the conductor in the respective section, wherein the actual length of the high impedance sections is longer than the actual length of the low impedance sections, further improving descattering characteristics.

In an embodiment, the radiator has at least one dipole comprising two of the at least one radiating structures, providing a reliable radiator.

Each of the radiating structures may form one half of the dipole.

In particular, the radiator may be a dual polarized radiator having four of the at least one radiating structures, wherein each two of the four radiating structures form a dipole.

In an aspect, the conductor of the radiating structure is located in a single plane, in particular wherein the conductors of all radiating structures are located in the same plane. This way, the manufacture of the radiator is simplified.

Within this disclosure, a "plane" may be understood to include two layers or surfaces of a carrier or substrate.

In an embodiment, the conductor has a width in the high impedance section of at most 4.5 mm, in particular at most 2.5 mm, more particularly at most 1 .5 mm; and/or wherein the conductor has a width in the low impedance section of at least 5 mm, in particular at least 7 mm, more particularly at least 9 mm. Thus, the desired impedances can be achieved reliably.

For example, the conductor has a layer thickness of 30 pm to 40 pm for PCB as a carrier or a thickness of 1 mm to 2 mm for sheet metal radiators in any of the high and low impedance sections.

The radiator is in particular configured to transmit and receive electromagnetic waves in the first frequency band and to be transmissive for electromagnetic waves in a second frequency band. The above mentioned exemplary values of the conductor widths are, for example, for the first frequency band being 698 MHz to 960 MHz and the second frequency band being 1427 MHz to 2690 MHz.

For improved radiation performance, the conductor may form a loop extending for at least 300°, in particular being a closed loop. The respective contour may also extend for at least 300° or is closed.

To further simplify manufacture, the conductor may be applied to a carrier, in particular wherein the conductor comprises conductor portions on more than one layers or surfaces of the carrier.

For example, the carrier is a substrate, e.g. a printed circuit board.

In an embodiment, the at least one of the high impedance sections is a meander section, in which the conductor forms a meander, in particular extending in an angle with respect to the contour. Using a meander, a parallel L-C-resonance may be introduced efficiently.

The angle may be at least 60°, in particular 90° and/or the meander may be a U-shaped path of the conductor.

For example, an additional conductor portion of the conductor is located between arms of the meander, in particular the additional conductor portion being located at the same or a different layer or surface of the carrier than the meander, increasing the capacitive effect of the meander.

The additional conductor portion may be capacitively coupled to the meander when located on a different layer or surface.

For example, an additional conductor portion of the conductor is provided on a different layer or surface than the meander, the additional conductor portion extending the meander by forming an additional loop.

In an aspect, at least one of the high impedance sections is a line section, particularly in which the conductor extends substantially parallel to the contour. The line section may provide high impedance with little capacitance or inductivity.

In an embodiment, at least one of the low impedance sections is a patch section, in which the conductor forms a patch being an open or filled loop, providing a high capacitance.

The conductor in the meander section and/or the patch section, i.e. the meander and/or the patch, may extend inwards with respect to the contour.

To further increase capacitance, an additional conductor portion of the conductor may be located within the area of the patch, in particular the additional conductor portion being located at the same or a different layer of the carrier or surface than the patch.

The additional conductor portion may be capacitively coupled to the patch when located on a different layer or surface.

The additional conductor portion may cover the area of the patch fully or partially.

For further improved signal quality, the conductor may have at least two low impedance sections, in particular two patch sections, and at least two high impedance sections, in particular two meander sections, located between the two low impedance sections.

Further, line sections may be provided between the patch sections and the closest meander sections. Adjacent meander sections may merge into one another. In particular, the radiating structure may be resonant in a first frequency band and/or transmissive for electromagnetic waves in a second frequency band, allowing a high signal quality for interleaved radiator assemblies or arrays.

For example, the first frequency band lies below the second frequency band, in particular fully.

The first frequency band lies below 1.0 GHz, for example the first frequency band is 698 MHz to 960 MHz. The second frequency band lies above 1 .0 GHz, for example the second frequency band is 1 .427 GHz to 2.69 GHz.

In an aspect the conductor is continuous along the full contour and/or continuous along the contour except for capacitive gaps, wherein ends of the conductor bordering the gap and facing each other are coupled capacitively, leading to further improvements on signal quality.

In an embodiment, at least one of the low impedance sections and/or at least one of the high impedance sections is bent out of the plane defined by the contour, in particular the conductor being a sheet metal or a component made by die casting. In this way, the mechanical stability and descattering properties are improved further.

For the above purpose, in an embodiment an antenna is further provided, the antenna having at least one radiator as described above, in particular the at least one radiator forming a first array.

For example, the antenna has at least one second radiator designed for a second frequency band, in particular the at least one second radiator forming a second array.

The first and second radiators or arrays may be interleaved.

Further, for the above mentioned purpose in an embodiment a mobile communication base station is provided, the base station having at least one antenna as described above.

For the above mentioned purpose, in an embodiment a user device for mobile communication is further provided, the user device comprising an antenna as described above.

The features and advantages described with respect to the radiator also apply to the antenna, the mobile communication base station and/or the user device and vice versa.

Brief Description of the Drawings

Further features and advantages will be apparent from the following description as well as the accompanying drawings, to which reference is made. In the drawings:

Fig. 1 shows a mobile communication base station according to an embodiment of the invention with an antenna according to an embodiment of the invention and a user device according to an embodiment of the invention with an antenna according to an embodiment of the invention,

Fig. 2 shows an enlarged view of a radiator according to an embodiment of the invention of an antenna of the mobile communication base station or the user device of Figure 1 ,

Fig. 3 shows an enlarged top view of one of the radiating structures of the radiator of Figure

2, Figs. 4, 5 show a radiating structure of a radiator according to a second embodiment of the invention in a top view and a bottom view, respectively,

Figs. 6, 7 show a radiating structure of a radiator according to a third embodiment of the invention in a top view and a bottom view, respectively, and

Fig. 8 shows a radiating structure of a radiator according to a fourth embodiment of the invention in a perspective view.

Detailed Description

Figure 1 shows an embodiment of a mobile communication base station 10 and an embodiment of a user device 12.

The mobile communication base station 10 has a plurality of antennas 14 for providing speech and data connections to user devices. Mobile communication base stations 10 are also referred to as mobile communication cell sites.

The mobile communication base station 10 may be an access network node of a radio access network of a telecommunication network, or any other similar 3rd Generation Partnership Project (3GPP) access nodes or non-3GPP access points.

Moreover, as will be appreciated by those of skill in the art, an access a network node is not necessarily limited to an implementation in which a radio portion and a baseband portion are supplied and integrated by a single vendor. Thus, it will be understood that network nodes may include disaggregated implementations or portions thereof.

For example, in some embodiments, the mobile communication base station 10 is an Open-RAN (ORAN) network node. An ORAN network node is a node in the telecommunication network that supports an ORAN specification (e.g., a specification published by the O-RAN Alliance, or any similar organization) and may operate alone or together with other nodes to implement one or more functionalities of any node in the telecommunication network, including one or more radio network nodes and/or core network nodes.

Examples of an ORAN network node include an open radio unit (O-RU), an open distributed unit (O- DU), and an open central unit (O-CU).

The antenna 14 of the mobile communication base station 10 is a multiband antenna to provide speech and data connections in various frequency bands.

The user device 12 has an antenna 16 and, in the illustrated embodiment, is a mobile phone. In further embodiments, the user device 12 may be a laptop computer, a customer-premises equipment (CPE), a vehicle, or the like. The antenna 16 of the user device 12 is also a multiband antenna allowing a speech and/or data connection to the mobile communication base station 10 and/or to a communication satellite.

Both antennas 14, 16 have an electromagnetic radiator. In the following, a radiator 18 as shown in Figure 2 which depicts a radiator for the mobile communication base station 10 will be discussed in more detail. The dimensions of the antenna 14 and/or the radiator 18 of the base station 10 are different from the dimensions of the antennas 16 and/or the radiator of the user device 12. The antenna 14 has a plurality of radiators 18 (also called first radiators 18 for differentiation) forming a first array configured for a first frequency band. Thus, the first radiators 18 are configured to transmit and receive electromagnetic waves in the first frequency band.

Further, the antenna 14 may comprise at least one second radiator 19 (one second radiator 19 is schematically shown in dashed lines for illustration purposes only), in particular a plurality of second radiators forming a second array for a second frequency band.

The first radiators 18, in particular the first array, and the second radiators, in particular the second array, may be interleaved with one another.

The first frequency band lies below the second frequency band, in particular fully.

For example, the first frequency band lies below 1.0 GHz, in particular the first frequency band may be 698 MHz to 960 MHz.

For example, the second frequency band lies above 1.0 GHz, in particular the second frequency band is 1.427 GHz to 2.69 GHz.

Figure 2 shows a radiator 18 mounted on a support 20.

In the shown embodiment, the radiator 18 is a dual polarized radiator having two dipoles 22 arranged orthogonally to one another.

The radiator 18 comprises four radiating structures 24. The radiating structures 24 are arranged in a 2 x 2 pattern and are attached to the support 20 with one of their corners, called inner corner 25 (as illustrated in Figure 3) in the following.

Each two diagonally opposite radiating structures 24 form one of the dipoles 22. Thus, one radiating structure 24 corresponds to a dipole half.

The radiating structures 24 comprise a carrier 26 and a conductor 28 each.

As can be seen in Figure 2, the four radiating structures 24 share the same carrier 26 to which the conductors 28 are applied.

It is also conceivable that each radiating structure 24 or a pair of radiating structures 24 have a separate carrier 26.

The carrier 26 is, for example, a substrate, like a printed circuit board.

The conductors 28 may be deposited on the carrier 26 using deposition techniques as known in the art. If PCB technology is used, the boards maybe etched, but other technologies such as MID or 3D printing are also conceivable.

It is also conceivable that the carrier 26 is a part, e.g. made of a dielectric, to which a thin film carrying the conductors 28 is applied. Moreover, it is also conceivable that the carrier 26 is a part, e.g. made of dielectric, fixating the conductors 28 that are made of at least one metal sheet. In the shown embodiment, the carrier 26 has two surfaces, namely a top surface (facing upwards in Figure 2) and a bottom surface (facing downwards in Figure 2) to which the conductor 28 is applied.

The conductor 28 may be applied in separate portions partly on the top surface as well as partly on the bottom surface. The conductor portions on the different surfaces form the conductor 28. In Figure 2, only the portion of the conductor 28 which is arranged on the top surface is illustrated.

As can further be seen in Figure 2, the radiating structures 24 of the radiator 18 are arranged in a single plane, which is the plane defined by the carrier 26.

As such, the conductors 28 also lie in the same plane. Within this disclosure, the conductor portions on the top surface and on the bottom surface of the carrier 26 are to be understood to be in the same plane.

It is conceivable that the carrier 26 is multilayered, i.e. a multilayered substrate. In this case, the single plane includes conductor portions in two layers of such a multilayered carrier 26.

Figure 3 shows a top view of the radiating structure 24 of the bottom right-hand side of the radiator 18 illustrated in Figure 2, wherein the carrier 26 is not shown. The inner corner 25 of the radiating structure 24 is located at the top left hand side of Figure 3.

Only the conductor 28 can be seen, wherein the unfilled parts of the shown conductor 28 are located on the top surface of the carrier 26 and the conductor 28 in solid black is located at the bottom surface of the carrier 26.

The shown radiating structure 24 is exemplary for the other radiating structures 24 of the radiator 18, i.e. the other radiating structures 24 are identical, but rotated.

It is also conceivable that the radiating structures 24 of the same radiator 18 differ from one another, in particular in the way the conductor 28 is arranged.

The conductor 28, starting e.g. from the inner corner 25, forms a loop extending at least for 300°. It is also conceivable that the conductor 28 is a fully closed loop.

As such, the conductor 28 is arranged to form an outer contour C, which may also be the outer contour of the carrier 26.

In the shown embodiment, the contour C is a square with three cut corners. The contour C may also be a ring, an ellipse, an octagon or any other shape.

The conductor 28 is continuous along the full contour C.

In the shown embodiment, the portion of the conductor 28 applied to the top surface of the carrier 26 is by itself already continuous except for a gap located at the corner of the contour C opposite to the inner corner 25.

At this gap, a conductor portion of the conductor 28 on the bottom surface of the carrier 26 is provided so that the conductor 28 as a whole is still continuous. It is conceivable that the carrier 26 may be continuous except for capacitive gaps, i.e. portions without a conductor portion on the top or bottom surface of the carrier 26. At such capacitive gaps, the ends of the conductor 28 bordering the gap which are facing each other are coupled capacitively.

The conductor 28 comprises sections of different impedances, namely low impedance sections 30 and high impedance sections 32.

The high impedance sections 32 are, in the shown embodiment, meander sections 34 and line sections 36.

In the line sections 36, the conductor 28 extends substantially parallel to the contour C.

In the meander sections 34, the conductor 28 forms a meander 38.

The meander is, for example, a U-shaped path of the conductor 28 extending inwards with respect to the contour C.

In the shown embodiment, the meander 38, more precisely the arms of the U-shaped path, extent with an angle of 90° to the contour C at the respective section.

Between the arms of the U-shaped path or arms of the meander 38, no conductor 28 is provided in the shown embodiment.

In the meander sections 34 and the line sections 36, the conductor 28 has a width w_h which is at most 4.5 mm, in particular at most 2.5 mm, more particularly at most 1.5 mm .

In particular, in the illustrated embodiment, the width w_h of the conductor 28 is constant in the high impedance sections 32.

In the shown embodiment, the low impedance sections 30 are patch sections 40.

In the patch sections 40, the conductor 28 forms a patch of a larger area compared to the high impedance sections 32.

The patch 42 is defined by a loop which may be open or, as seen in the shown embodiment, solidly filled.

Similarly to the meander 38, the patch 42 extends inwardly with respect to the contour C.

The patch 42 may be regarded as a conductor 28 with a width wi. The width wi is, in the shown embodiment, at least 5 mm, in particular at least 7 mm, more particularly at least 9 mm.

As such, the low impedance sections 30 may have an impedance per unit length along the contour C being smaller than one half, in particular smaller than 1/10 of the impedance per unit length along the contour C of the high impedance sections 32.

Further, each of the low impedance sections 30, e.g. the patch sections 40, and of the high impedance sections 32, e.g. the meander sections 34 or the line sections 36, have a respective length L along the contour. C. The length L along the contour is the extent of the respective section 30, 32, 34, 36, 40 parallel to the contour.

In other words, for example, the meander sections 34 have a length L along the contour C which is not the actual length of the conductor 28 following the path of the conductor 28 through the meander 38 but the distance between the outer sides of the arms of the meander 38.

In the first embodiment, the low impedance sections 30 and the high impedance sections 32 are arranged in series.

Starting from the inner corner 25 and following the conductor 28 counterclockwise, the first section is a line section 36 with a length L1 along the contour C.

The second section adjacent to the first section is a meander section 34 with a length L2 along the contour C.

The third section extending from the second section is again a line section 36 having a length L3 along the contour C.

The fourth section extending from the third section in a 45° angle is a patch section 40, i.e. a low impedance section 30, having a length L4.

The patch section 40 is located at a first corner of the contour C.

The fifth section extends in a 45° angle from the fourth section and is, again, a line section 36. The third section and the fifth section are perpendicular to one another.

The fifth section has a length L5 along the contour C.

From the fifth section, the sixth section extends, being a meander section 34 with a length L6 along the contour C.

The next section, the seventh section, is again a line section 36 with a length L7 along the contour C.

The eighth section adjacent to the seventh section is a patch section 40, angled at 45° with respect to the seventh section.

This patch section 40 has an additional conductor portion 44 of the conductor 28 on the bottom surface of the carrier 26 extending over the entire area of the respective patch 42. The additional conductor portion 44 is coupled to the patch 42 capacitively through the material of the carrier 26.

The conductor portion on the top surface of the carrier 26 comprises a gap in the middle of the patch section 40.

The patch section 40 has a length L8 along the contour C.

Extending in a 45° angle of the eighth section is the ninth section being a line section 36 corresponding to the seventh section.

In fact, the ninth to fifteenth section correspond to the seventh to first section, respectively. Thus, a total length along the contour C of the low impedance sections 30 and of the high impedance sections 32 can be determined.

The total length along the contour C of the low impedance sections 30 is the sum of the lengths along the contour C of each of the low impedance sections 30, i.e. L4 + L8 + L12.

Likewise, the total length along the contour C of the high impedance sections 32 is the sum of the lengths of each of the high impedance sections 32, namely L1 + L2 + L3 + L5 + L6 + L7 + L9 + L10 + L11 + L13 + L14 + L15.

The total length along the contour of the high impedance sections 32 is longer than the total length along the contour C of the low impedance sections 30. In particular, the total length along the contour C of the high impedance sections 32 may be at least two times, in particular at least three times longer than the total length of the low impedance sections 30 along the contour C.

Further, in the illustrated embodiment, the actual length of the high impedance sections, i.e. the of sum the actual lengths of all high impedance sections, is greater than the actual length of the low impedance sections, i.e. the sum of the actual lengths of all low impedance sections.

In this way, the radiating structure 24 is resonant in the first frequency band and transmissive for electromagnetic waves in the second frequency band.

The first frequency band includes the radiation frequency of the radiator 18.

Thus, even though the array of second radiators is interleaved with a first array of (first) radiators 18, the electromagnetic waves in the second frequency band pass the radiators 18 with only little losses or scattering. Thus, the signal quality is improved.

The frequency bands, in particular the resonances and transmissive band, are tunable by the choice of low and high impedance sections 30, 32, their amount and length along the contour.

In this case, meanders 38 function as an LC component, wherein patches 42 function as a capacitance.

Figures 4 to 8 show further embodiments of radiating structures 24 which correspond substantially to the first embodiment. Thus, in the following, only the differences are explained and the same and functionally the same components are labeled with the same reference signs.

Figures 4 and 5 show a second embodiment of a radiating structure 24, wherein, just like in Figure 3, the carrier 26 has been omitted.

Figure 4 shows the radiating structure 24 in a top view and Figure 5 in a bottom view.

In difference to the first embodiment, between each pair of patch sections 40 in the corners of the contour C and between the inner corner 25 and the respective closest patch sections 40, two meander sections 34 are provided.

The meander sections 34 between the inner corner 25 and the closest patch section 40 are different from the remaining meander sections 34 and the meander sections 34 explained with respect to the first embodiment. An additional conductor portion 46 is present in the meander sections 34 closest to the inner corner 25 between the arms of the meander 38. The additional conductor portion 46 is located at the bottom side of the carrier 26 in the region of the base of the U-shaped path of the meander 28.

The additional conductor portion 46 extends along the full length of the respective meander section 34 along the contour C.

The meander 38 and the additional conductor portion 46 are coupled capacitively through the carrier 26.

The meanders 38 of the meander sections 34 closest to the patch section 40 also comprise the additional conductor portion 46 at the bottom surface of the carrier 26. In addition, on the top surface of the carrier 26, the area between the arms of the meander 38 is partly filled starting from the base of the U-shaped path towards the contour C, forming a small patch.

Figures 6 and 7 show a third embodiment of the radiating structure 24 corresponding to the views of Figures 4 and 5.

In the third embodiment, again two meander sections 34 are provided on each side of the contour C between the inner corner 25 and/or the patch sections 40, respectively.

The meander sections 34 closest to the inner corner 25 have meanders 38 extending inwards at an angle smaller than 90° with respect to the contour C. The angle is at least 60°.

In addition, the meanders 38 do not extend as far inwards as the meanders 38 of the other meander sections 34.

Further, additional conductor portions 48 are provided on the bottom surface of the carrier 26. The additional conductor portions 48 form a rectangular loop, the path of the loop having a width corresponding to that of the meander 38.

One edge of the loop covers the base of the U-shaped path of the meander 38 and couples capacitively to the meander 38. Thus, seen from a top view (Fig. 6), the additional conductor portions 48 extend the respective meander 38.

Further, the conductor 28 has various protrusions 50 extending inwardly from the line sections 36. The protrusions 50 may overlap with additional conductor portions 48 on the bottom surface of the carrier 26.

Figure 8 shows a fourth embodiment of the radiating structure 24 in a perspective view.

Similar to the conductor 28 located on the top side of the radiator according to the second embodiment shown in Figure 4, between each pair of patch sections 40 in the corners of the contour C and between the inner corner 25 and the respective closest patch sections 40, two meander sections 34 are provided.

The meanders 38 of the meander sections 34 closest to the patch section 40 have the area between the arms of the meander 38 partly filled starting from the base of the U-shaped path towards the contour C, forming a small patch.

In contrast to the previous embodiments, the meanders 38 of the meander sections 34 and the patches 42 of the patch sections 40 are bent out of the plane defined by the contour C. In the shown embodiment, the meanders 38 of the meander section 34 are bent downwards, for example by an angle of approximately 90° with respect to the plane defined by the contour C. An angle of approximately 45° or any other angle is also conceivable.

The patches 42 of the patch sections 40 are bent upwards, for example by an angle of approximately 45° with respect to the plane defined by the contour C. An angle of approximately 90° or any other angle is also conceivable.

It is also conceivable that the meanders 38 of the meander section 34 are bent upwards and/or that the patches 42 of the patch sections 40 are bent downwards.

In general, at least one low impedance section 30 and/or at least one high impedance section 32 may be bent out of the plane defined by the contour C.

The bent sections have a positive effect on mechanical stability and also improve descattering.

By use of these additional elements and/or bent section explained with respect to the second, third and fourth embodiment, the first and second frequency band may further be tuned to the exact needs of the antenna 14. The elements may be combined freely.

In the foregoing detailed description, a radiator for a mobile communication base station was discussed. A radiator for an antenna of a user device may be structurally different from said radiator for a mobile communication base station, e.g. the radiator may be a monopole instead of a dipole. Still, a conductor having low impedance sections and high impedance sections, wherein a total length of the high impedance sections along the contour is longer than a total length of the low impedance sections along the contour as described in detail above may be included in such a radiator for an antenna of a user device.

Claims

1. Radiator for an antenna (14), comprising at least one radiating structure (24) with a conductor (28), the conductor (28) defining a contour (C) of the radiating structure (24) and the conductor (28) having low impedance sections (30) and high impedance sections (32), wherein a total length of the high impedance sections (32) along the contour (C) is longer than a total length of the low impedance sections (30) along the contour (C).

2. Radiator according to claim 1 , characterized in that the total length of the high impedance sections (32) along the contour (C) is at least two times, in particular at least three times longer than the total length of the low impedance (30) sections along the contour (C).

3. Radiator according to claim 1 or 2, characterized in that the low impedance sections (30) and the high impedance sections (32) are arranged in series.

4. Radiator according to any of the preceding claims, characterized in that the low impedance sections (30) and the high impedance sections (32) have an actual length being the length of the conductor (28) in the respective section, wherein the actual length of the high impedance sections (32) is longer than the actual length of the low impedance sections (30).

5. Radiator according to any of the preceding claims, characterized in that the radiator (18) has at least one dipole (22) comprising two of the at least one radiating structures (24).

6. Radiator according to any of the preceding claims, characterized in that the conductor (28) of the radiating structure (24) is located in a single plane, in particular wherein the conductors (28) of all radiating structures (24) are located in the same plane.

7. Radiator according to any of the preceding claims, characterized in that the conductor (28) has a width (Wh) in the high impedance sections (32) of at most 4.5 mm, in particular at most 2.5 mm, more particularly at most 1.5 mm; and/or wherein the conductor (28) has a width (wi) in the low impedance sections (30) of at least 5 mm, in particular at least 7 mm, more particularly at least 9 mm.

8. Radiator according to any of the preceding claims, characterized in that the conductor (28) forms a loop extending for at least 300°, in particular being a closed loop.

9. Radiator according to any of the preceding claims, characterized in that the conductor (28) is applied to a carrier (26), in particular wherein the conductor (28) comprises conductor portions on more than one layers or surfaces of the carrier (26).

10. Radiator according to any of the preceding claims, characterized in that at least one of the high impedance sections (32) is a meander section (34), in which the conductor (28) forms a meander (38), in particular extending in an angle with respect to the contour (C).

11 . Radiator according to claim 10, characterized in that an additional conductor portion (48) of the conductor is located between arms of the meander (38), in particular the additional conductor portion (48) being located at the same or a different layer or surface of the carrier (26) than the meander (38).

12. Radiator according to any of the preceding claims, characterized in that at least one of the high impedance sections (32) is a line section (36), particularly in which the conductor (28) extends substantially parallel to the contour (C).

13. Radiator according to any of the preceding claims, characterized in that at least one of the low impedance sections (30) is a patch section (40) in which the conductor (28) forms a patch (42) being an open or filled loop.

14. Radiator according to claim 13, characterized in that an additional conductor portion (44) of the conductor (28) is located within the area of the patch (42), in particular the additional conductor portion (44) being located at the same or a different layer or surface of the carrier (26) than the patch (42).

15. Radiator according to any of the preceding claims, characterized in that the conductor (28) has at least two low impedance sections (30), in particular two patch sections (40), and at least two high impedance sections (32), in particular meander sections (34), located between the two low impedance sections (30).

16. Radiator according to any of the preceding claims, characterized in that the radiating structure (24) is resonant in a first frequency band and/or transmissive for electromagnetic waves in a second frequency band.

17. Radiator according to any of the preceding claims, characterized in that the conductor (28) is continuous along the full contour (C) and/or continuous along the contour (C) except for capacitive gaps, wherein ends of the conductor (28) bordering the gap and facing each other are coupled capacitively.

18. Radiator according to any of the preceding claims, characterized in that at least one of the low impedance sections (30) and/or at least one of the high impedance sections (32) is bent out of the plane defined by the contour (C), in particular the conductor (28) being a sheet metal or a component made by die casting.

19. Antenna having at least one radiator (18) according to any one of the preceding claims, in particular the at least one radiator (18) forming a first array.

20. Antenna according to claim 19, wherein the antenna (14, 16) has at least one second radiator configured for a second frequency band, in particular the at least one second radiator forming a second array.

21. Mobile communication base station having at least one antenna (14, 16) according to claim 19 or 20.

22. User device for mobile communication having at least one antenna (14, 16) according to claim 19 or 20.