The invention relates to a mobile communication antenna which can be used to transmit and receive mobile communication signals. The mobile communication antenna is configured to communicate with one or more mobile devices that can be held by a user. Those mobile communication antennas are normally mounted on masts or on roof tops.
A radiator for a mobile communication antenna is known from the EP 1 434 300 A2. The radiator is cross-shaped and comprises four connection points. Each connection point can either be used for feeding a signal or for establishing a connection to ground. As such, the radiator can be used for one polarization or two polarizations. The radiator is made of die-cast metal, wherein the feeding connection is soldered to respective signal line.
As a result, care has to be taken to obtain a reproducible connection regarding the solder joints. This results in PIM (passive intermodulation) problems. Furthermore, the use of die-cast materials can result in a decreased electrical performance. The possibilities on how the signal can be fed limits also the electrical performance. Another disadvantage is that an expensive tool is needed. Furthermore, it is more difficult/expensive to adapt or scale the radiator. The choice of materials is also limited. Regarding soldering, an appropriate material has to be chosen or the surface of the material has to be treated/coated (cost, PIM). Die-casted parts are heavy because of higher wall thicknesses. It is also more difficult to implement very fine or complex structures.
As such, it is the object of the present invention to create a mobile communication antenna with a radiator that can be easily produced thereby offering a high flexibility and minimum passive intermodulation (PIM).
The object is solved with the mobile communication antenna according to claim 1. Advantageous further developments of the mobile communication antenna are described in the dependent claims.
A mobile communication antenna according to the present invention comprises a support arrangement and at least one radiator. The at least on radiator is preferably configured to transmit and receive mobile communication signals in two polarizations. Polarizations could be for example linear +45°/−45° slant, linear 0°/90° horizontal and vertical, elliptic or circular. The mobile communication antenna can be mounted on a mast and/or on a roof for example. The at least one radiator comprises first and second dipoles, wherein the first and second dipoles each comprise a first and a second dipole half. The first and second dipoles are arranged on a first side of the support arrangement. Each dipole half comprises first and second connecting elements, wherein the first and second connecting elements comprise a first end and a second end. Each connecting element is arranged with its first end on the support arrangement and extends away from it. Each dipole half comprises a radiator structure, wherein the second ends of the first and the second connecting elements of the respective dipole half are connected to one another via the radiator structure of the respective dipole half. As such, the radiator structure is spaced apart from the support arrangement. In addition, each dipole half is feedable via the first and/or second connecting element. Each dipole half is also connected or coupled to ground via the first and/or second connecting element.
Compared to the state of the art, the radiator according to the present invention comprises a larger number of connection possibilities (first ends of the first and second connecting element) so that it can be used more flexible. As such the feeding of a signal as well as a connection to ground is possible in close proximity. As such, the electrical performance is increased.
In a preferred embodiment of the mobile communication antenna, the at least one radiator is made of a single piece. This means the first and second dipoles are integrally formed. This comes with the advantage of an easier placement.
In another preferred embodiment of the mobile communication antenna, the at least one radiator is a bent part and also a punched and/or lasered part. By using those processes instead of a die-cast process, precise structures of the at least one radiator can be obtained. Furthermore, the at least one radiator is thinner than the radiator according to the state of the art. In addition, production is less expensive compared to the radiator of the state of the art.
In a preferred embodiment of the mobile communication antenna, a connecting element of the first dipole half of the first dipole is formed integrally (single-piece) with a connecting element of the adjacent first dipole half of the second dipole in the region of the respective first ends. In other words, the two connecting elements form a joint connection in the area of their first ends. Furthermore, a connecting element of the second dipole half of the first dipole is formed integrally with the connecting element of the adjacent second dipole half of the second dipole in the region of the respective first ends. It is beneficial, that the at least one radiator is made of a single-piece by connecting respective connecting elements at their first ends together. As such, adjacent connecting elements of the different dipoles are connected together in the region of their first ends, wherein connecting elements of the same dipole half are connected together by using the radiator structure arranged at their second ends.
In a preferred embodiment of the mobile communication antenna, the first connecting element of the first dipole half of the first dipole is formed integrally (single-piece) with the second connection element of the first dipole half of the second dipole in the region of the respective first ends so that a first support surface is formed. The same is true for the other connecting elements. As such, the second connecting element of the first dipole half of the first dipole is formed integrally with the first connecting element of the second dipole half of the second dipole in the region of the respective first ends thereby forming a second support surface. The first connecting element of the second dipole half of the first dipole is formed integrally with the second connecting element of the second dipole half of the second dipole in the region of the respective first ends thereby forming a third support surface. The second connecting element of the second dipole half of the first dipole is formed integrally with the first connecting element of the first dipole half of the second dipole in the region of the respective first ends thereby forming a fourth support surface. It is very beneficial that respective first, second, third and fourth support surfaces are formed which allow a smooth placement of the at least one radiator on the support arrangement.
In another preferred embodiment of the mobile communication antenna, the support arrangement comprises a metal layer on the first side if the support arrangement which is connected to ground. The first, second, third and fourth support surfaces are arranged on said metal layer. It is very beneficial that by having a support surface which is predominantly or completely smooth that a reproducible coupling to ground can be achieved. This is preferably true for all of the support surfaces and therefore for all of the dipole halves.
In another preferred embodiment of the mobile communication antenna, a dielectric is arranged between the metal layer and the first, second, third and fourth support surfaces. The dielectric is preferably formed by solder resist. In that case, the respective dipole halves are “coupled” to ground. If instead a solder connection (galvanic connection) would have been used, each dipole half would be “connected” to ground. The use of a solder resist as a dielectric comes also with the advantage that the support surfaces can be arranged really closed to the metal layer so that a strong and reproducible coupling is achieved.
In another preferred embodiment of the mobile communication antenna, the first, second, third and/or fourth support surface is glued to the first side of the support arrangement. In that case no external holding device has to be used so that the mobile communication antenna has a compact design.
In another preferred embodiment of the mobile communication antenna, the first and second support surfaces are spaced apart from each other thereby forming a first gap. The second and the third support surfaces are also spaced apart from each other forming a second gap. The same is also true for the third and fourth support surfaces which are spaced apart from each other forming a third gap. The fourth and first support surfaces are spaced apart from each other forming a fourth gap. A metal layer on the first side of the support arrangement comprises first, second, third and fourth recesses in the region of the gaps, thereby forming first, second, third and fourth slots respectively. In other words, between the respective support surfaces where the gap is formed, the metal layer comprises respective recesses. A second side of the support arrangement comprises first, second, third and fourth feed structures. The first feed structure crosses the first slot. The second feed structure crosses the second slot. The third feed structure crosses the third slot. The fourth feed structure crosses the fourth slot. In that case, the at least one radiator can be fed without the use of any solder joint and/or without the use of any cable connection just by using a slot structure.
In a preferred embodiment of the mobile communication antenna, the first feed structure is a metal layer on the second side of the support arrangement, wherein the first feed structure can be widened in the region of the first slot. In addition or alternatively, the second feed structure is a metal layer on the second side of the support arrangement, wherein the second feed structure can be widened in the region of the second slot. In addition or alternatively, the third feed structure is a metal layer on the second side of the support arrangement, wherein the third feed structure can be widened in the region of the third slot. In addition or alternatively, the fourth feed structure is a metal layer on the second side of the support arrangement, wherein the fourth feed structure can be widened in the region of the fourth slot. This comes with the benefit that the coupling is increased. In another preferred embodiment of the mobile communication antenna, the first, second, third and fourth recesses comprise a widened end, whereby the first, second, third and fourth slots also comprise a widened end. This increases the electrical performance. In addition or alternatively, the first, second, third and fourth feed structures widen towards their open ends. In addition or alternatively, the length of the first, second, third and fourth feed structures from where they cross the respective slot to the open ends is approximately λ/4 where λ is the wave length corresponding to the center frequency of the frequency band the radiator is used for and taking into account the electrical properties of the support arrangement.
In another preferred embodiment of the mobile communication antenna, the first, second, third and fourth support surfaces comprise a cutout that is open to one side. A metal layer on the first side of support arrangement comprises first, second, third and fourth recesses in the region of the first, second, third and fourth cutouts of the respective support surface. As such, first, second, third and fourth slots are formed. A second side of the support arrangement comprises first, second, third and fourth feed structures. The first feed structure crosses the first slot, the second feed structure crosses the second slot, the third feed structure crosses the third slot and the fourth feed structure crosses the fourth slot. As such, two connecting elements of different dipole halves of different dipoles are feedable with one signal. In other words, the radiator is now fed in all of its four corners. Preferably, the cutouts are directed to the outside of the at least one radiator and as such, the cutouts are not facing the centre of the at least one radiator. As such, another radiator can be placed inside such a radiator.
In a preferred embodiment of the mobile communication antenna, the at least one radiator is attached to the support arrangement with its first and second dipoles solder-free. As such, the manufacturing process is simplified and passive intermodulation is reduced.
In another preferred embodiment of the mobile communication antenna, exactly one connecting element of the first dipole half of the first dipole and exactly one connecting element of the second dipole half of the first dipole and exactly one connecting element of the first dipole half of the second dipole and exactly one connecting element of the second dipole half of the second dipole are connected to each other and formed in one piece and are capacitively coupled or galvanically connected to ground. The other connecting element of the first dipole half of the first dipole and the other connecting element of the second dipole half of the first dipole are feedable with a first signal in phase or in antiphase. The other connecting element of the first dipole half of the second dipole and the other connecting element of the second dipole half of the second dipole are also feedable with a second signal in phase or in antiphase.
In another preferred embodiment of the mobile communication antenna, the radiator structure of each dipole half comprises radiator segments extending away from the first and the second connecting elements of the respective dipole half and spaced apart from the first and second connecting elements when running towards each other. The radiator segments are then connected to each other thereby enclosing an area. The radiator structure comprises a separation segment, wherein the area is separated into two sub-areas of the different length such that the radiator structure is configured to operate in different mobile communication bands. The separation segment preferably extends from that position where the radiator segments are connected to each other in direction of the first and second connecting elements.
In a preferred embodiment of the mobile communication antenna, a plurality of radiators is arranged on the first side of the support arrangement. The support arrangement is a printed circuit board. A metal sheet arrangement and/or partially metallized dielectrics like plastic is/are arranged between some or all of the radiators on the first side of the support arrangement, thereby forming a reflector arrangement. The metal sheet arrangement and/or the partially metallized dielectrics is/are preferably that part which gives stability to the support arrangement. The support arrangement can be screwed to the metal sheet arrangement and/or to the partially metallized dielectrics. Preferably, expanding rivets are used for fixing the support arrangement to the metal sheet arrangement and/or to the partially metallized dielectrics. As such, no metal screws are needed for a defined contact. This reduces or avoids PIM. The printed circuit board preferably comprises only one dielectric in the middle and metal layers on the first side and the second side.
In another preferred embodiment, the mobile communication antenna comprises different radiators. A first radiator is thereby arranged within a second radiator.
Various exemplary embodiments of the invention will be described as an example hereinafter with reference to the drawings. The same items have the same reference numbers. The corresponding figures of the drawings show in detail:
The at least one radiator 3 is arranged on a first side 2a of the support arrangement 2. Within
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The at least one radiator 3 as well as the support arrangement 2 and the additional components 4 are enclosed by a radome 9.
With a dashed line the signal line 6 is shown. The signal line 6 preferably runs predominantly on the second side 2b of the support arrangement 2. A solid line 12 describes a metal layer 8a connected to ground. This indicated that the at least one radiator 3 is connected and/or coupled to ground.
The first and second dipoles 15, 18 are arranged at the first side 2a of the support arrangement 2. A reflector arrangement 13 is also shown comprising sidewalls. Each dipole half 16, 17, 19, 20 comprises first and second connecting elements 21, 22, wherein the first and second connecting elements comprise a first end 23 and a second end 24.
Each connecting element 21, 22 is arranged with its first end 23 on the support arrangement 2 and extends away from it. Each connecting element 21, 22 could be aligned perpendicular to the support arrangement 2 or at an angle. Each dipole half 16, 17, 19, 20 comprises a radiator structure 25. The second ends 24 of the first and the second connecting elements 21, 22 of the respective dipole half 16, 17, 19, 20 are connected to one another via the radiator structure 25 of the respective dipole half 16, 17, 19, 20. In other words, the second ends 23 of the first and the second connecting element 21, 22 of one dipole half 16, 17, 19, 20 are connected to each other via the radiator structure 25.
The radiator structure 25 is preferably aligned parallel to the support arrangement 2. However, the radiator structure 25 could also be aligned at an angle towards or away from the support arrangement 2.
As will be explained in the following, each dipole half 16, 17, 19, 20 is feedable via its first and/or the second connecting element 21, 22 and is also coupled or connected to ground via its first and/or second connecting element 21, 22.
It can be seen that the at least one radiator 3 with its first and second dipoles 15, 18 is made of a single piece.
The connecting element 21, 22 of the first dipole half 16 of the first dipole 15 is formed integrally with the connecting element 21, 22 of the adjacent first dipole half 19 of the second dipole 18 in the region of the respective first ends 23.
Also, a connecting element 21, 22 of the second dipole half 17 of the first dipole 15 is formed integrally with the connecting element 21, 22 of the adjacent second dipole half 20 of the second dipole 18 in the region of the respective first ends 23.
This can also be described more precisely with respect to
The first connecting element 21 of the second dipole half 17 of the first dipole 15 is formed integrally with the second connecting element 22 of the second dipole half 20 of the second dipole 18 in the region of the respective first ends 23 thereby forming a third support surface 28.
The second connecting element 22 of the second dipole half 18 of the first dipole 15 is formed integrally with the first connecting element 21 of the first dipole half 19 of the second dipole 18 in the region of the respective first ends 23 thereby forming a fourth support surface 29.
As such, the at least one radiator 3 is formed in a single piece.
The support arrangement 2 comprises a metal layer 8a on the first side 2a which is connected to ground. The first, second, third and fourth support surfaces 26, 27, 28, 29 are arranged on said metal layer 8a.
Preferably a dielectric is arranged between the metal layer 8a and the first, second, third and fourth support surfaces 26, 27, 28, 29. More preferably, the dielectric is formed of a solder resist.
In that case the coupling to ground is made without the use of a solder joint. However, the first, second, third and/or fourth support surface 26, 27, 28, 29 could also be soldered to the metal layer 8a on the first side 2a of the support arrangement 2. It could also be possible, that a part of the first, second, third and/or fourth support surfaces 26, 27, 28, 29 extends through the support arrangement 2 so that the respective part can be soldered to the metal layer 8b on the second side 2b of the support arrangement 2.
However, the first, second, third and/or fourth support surface 26, 27, 28, 29 is preferably glued to the first side 2a of the support arrangement 2.
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The radiator structure 25 of each dipole half 16, 17, 19, 20 comprises radiator segments 30. The radiator segments 30 extend away from the first and second connecting elements 21, 22 starting at their second ends 24. Within
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The embodiment of
Reference is also made to
The first, second, third and fourth slots 37, 38, 39, 40 can be seen in
However, the first and third slots 37, 39 could also end spaced apart from each other. However, they are preferably aligned coaxially. The second and fourth slots 38, 40 could also end spaced apart from each other. However, they are preferably aligned coaxially to each other.
The slots 37, 38, 39, 40 are preferably filled with the dielectric 7 of the support arrangement 2, namely the dielectric 7 of the printed circuit board arrangement. The slots 37, 38, 39, 40 could also be filled with air.
Referring back to
In addition, the first feed structure 41 is a metal layer 8b on the second side 2b of the support arrangement 2, wherein the first feed structure 41 widens in the region of the first slot 37. The second feed structure 42 is a metal layer 8b on the second side 2b of the support arrangement 2, wherein the second feed structure 42 widens in the region of the second slot 38. The third feed structure 43 is a metal layer 8b on the second side 2b of the support arrangement 2, wherein the third feed structure 43 widens in the region of the third slot 39. The fourth feed structure 44 is a metal layer 8b on the second side 2b of the support arrangement 2, wherein the fourth feed structure 44 widens in the region of the fourth slot 40.
The first, second, third and fourth recesses in the metal layer 8a on the first side 2a of the support arrangement 2 comprises a widened end, whereby the first, second, third and fourth slots 37, 38, 39, 40 also comprise a widened end.
The first, second, third and fourth feed structures 41, 42, 43, 44 preferably widen towards the open end.
The length of the first, second, third and fourth feed structures 41, 42, 43, 44 from where they cross the respective slot 37, 38, 39, 40 to the open end is approximately λ/4. This allows that signal power is reflected directly towards the respective slot 37, 38, 39, 40.
The first and the third feed structures 41, 43 are connected together and are fed by the same first signal. The second and the fourth feed structures 42, 44 are connected together and are fed by the same second signal.
The first and the second connecting elements 21, 22 are C-shaped. In the middle they are spaced further apart from each other than the region of the first and second ends 23, 24.
The first, second, third and fourth support surfaces 26, 27, 28, 29 comprise a cutout 50 that is open to one side. The cutout 50 has preferably a circumferential diameter. A metal layer 8a on the first side 2a of the support arrangement 2 comprises first, second, third and fourth recesses in the region of the respective cutouts 50, thereby forming first, second, third and fourth slots 37, 38, 39, 40. A second side 2b of the support arrangement 2 comprises first, second, third and fourth feed structures 41, 42, 43, 44.
The first feed structure 41 crosses the first slot 37. The second feed structure 42 crosses the second slot 38. The third feed structure 43 crosses the third slot 39. The fourth feed structure 44 crosses the fourth slot 40.
The first feed structure 41 and the third feed structure 43 are fed with the same signal. The signal lines 6 to the first feed structure 41 and to the third feed structure 43 are preferably of the same length. The second feed structure 42 and the fourth feed structure 44 are fed with the same signal. The signal lines 6 to the second feed structure 42 and to the fourth feed structure 44 are preferably of the same length.
The respective first, second, third, fourth slot 37, 38, 39, 40 have one end which form is preferably adapted to the form of the respective cutout 50. In that case, the form corresponds to circle. Starting from this one end, the respective first, second, third, fourth slot 37, 38, 39, 40 widens towards a second end. The slots 37, 38, 39, 40 are not connected to each other in this embodiment.
The first, second, third and fourth feed structure 41, 42, 43, 44 crosses the respective first, second, third, fourth slot 37, 38, 39, 40 between the first and second ends of the respective slot 37, 38, 39, 40. Preferably, the respective feed structure 41, 42, 43, 44 crosses the respective slot 37, 38, 39, 40 at a region closer to the first end than to the second end.
Referring again to
In that case, exactly one connecting element 21, 22 of the first dipole half 16 of the first dipole 15 and exactly one connecting element 21, 22 of the second dipole half 17 of the first dipole 15 and exactly one connecting element 21, 22 of the first dipole half 19 of the second dipole 18 and exactly one connecting element 21, 22 of the second dipole half 20 of the second dipole 18 are connected to each other and formed in one piece. They are preferably capacitively coupled to ground. A galvanic connection, for example by the use of solder would also be possible. Preferably, the respective connecting elements 21, 22 cross each other approximately in the centre area of the radiator 3. This connection could preferably be enlarged so that the coupling is increased.
The other connecting element 22, 21 of the first dipole half 16 of the first dipole 15 and the other connecting element 22, 21 of the second dipole half 17 of the first dipole 15 are feedable with a first signal in phase or antiphase. Those other connecting elements 22, 21 are preferably soldered to a respective signal line 6. They could also extend through the support arrangement 2 and in turn be soldered on the second side 2b of the support arrangement 2 to the respective signal line 6.
The other connecting element 22, 21 of the first dipole half 19 of the second dipole 18 and the other connecting element 22, 21 of the second dipole half 20 of the second dipole 18 are feedable with a second signal in phase or antiphase. Those other connecting elements 22, 21 are preferably soldered to a respective signal line 6. They could also extend through the support arrangement 2 and in turn be soldered on the second side 2b of the support arrangement 2 to the respective signal line 6.
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Some of the embodiments contemplated herein are described more fully with reference to the accompanying drawings. Other embodiments, however, are contained within the scope of the subject matter disclosed herein. The disclosed subject matter should not be construed as limited to only the embodiments set forth herein; rather, these embodiments are provided by way of example to convey the scope of the subject matter to those skilled in the art.
The present invention may, of course, be carried out in other ways than those specifically set forth herein without departing from essential characteristics of the invention. The present embodiments are to be considered in all respects as illustrative and not restrictive, and all changes coming within the meaning and equivalency range of the appended claims are intended to be embraced therein.
Filing Document | Filing Date | Country | Kind |
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PCT/EP2021/073520 | 8/25/2021 | WO |