Disclosed embodiments relate to the field of communication technologies, and specifically, to an antenna system and a base station antenna feeder system.
With development of wireless communication technologies, a base station can support more communication frequency bands. In this case, a structure of a base station antenna is increasingly complex. As antenna arrays in a large quantity of frequency bands and feeder networks are integrated on a single antenna, antenna integration of the single antenna is increasingly high.
In conventional technologies, to implement high integration of an antenna system, antenna unit arrays in a plurality of frequency bands are integrated into one antenna system to form a multi-frequency band antenna system. The multi-frequency band antenna system may include a first frequency band radiation element array and a second frequency band radiation element array, and a frequency selective surface (FSS) may be disposed between the first frequency band radiation element array and the second frequency band radiation element array. However, as an area of the frequency selective surface is limited, space for disposing the first frequency band radiation element array and the second frequency band radiation element array is limited. Consequently, integration of an antenna is low.
This disclosure provides an antenna system and a base station antenna feeder system. The antenna system includes radiation element arrays in at least two frequency bands. The antenna system has better signal quality and higher integration. In addition, independent evolution of radiation element arrays in different frequency bands can be implemented.
According to a first aspect, an antenna system includes a frequency selective surface, a first frequency band radiation element array, a second frequency band radiation element array, and a phase shifter. The first frequency band radiation element array, the frequency selective surface, and the second frequency band radiation element array are sequentially disposed. In other words, the frequency selective surface is disposed between the first frequency band radiation element array and the second frequency band radiation element array. The frequency selective surface is configured to reflect a signal of the first frequency band radiation element array and transmit a signal of the second frequency band radiation element array. The signal includes an emitted signal and also includes a received signal. The phase shifter is connected to the first frequency band radiation element array, so that the phase shifter is configured to feed the first frequency band radiation element array. The phase shifter includes a cavity, where the cavity is disposed at an edge of the frequency selective surface, and a first extension direction of the cavity is consistent with a second extension direction of the first frequency band radiation element array. In this technical solution, the cavity of the phase shifter is disposed at the edge of the frequency selective surface, and when the signal of the second frequency band radiation element array is transmitted from the frequency selective surface, an insertion loss is small. This helps improve signal quality of the antenna system. In addition, when the second frequency band radiation element array is disposed, there is no need to consider possible interference that is caused by the first frequency band radiation element array to the second frequency band radiation element array. This helps implement decoupling between the first frequency band radiation element array and the second frequency band radiation element array, to flexibly dispose the first frequency band radiation element array and the second frequency band radiation element array as required. In addition, in this solution, the frequency selective surface may be disposed in space of the entire antenna system that faces an antenna, and there is no need to additionally dispose an auxiliary structure of the phase shifter. Therefore, a side that is of the frequency selective surface and that is away from the first frequency band radiation element array may have larger space for disposing the second frequency band radiation element array. In this way, integration of the antenna system is improved. In this solution, the first frequency band radiation element array and the second frequency band radiation element array are arranged in a stacked manner, so that radiation element arrays in at least two frequency bands can be deployed on a single antenna. From the perspective of a direction perpendicular to a surface of the frequency selective surface, the antenna system wholly occupies the antenna, and deployment is easy. In addition, the integration of the antenna system is high, and in this case, an area of the antenna system is small, and wind load is small.
The frequency selective surface includes a first side edge and a second side edge. The first side edge and the second side edge may be two opposite side edges of the frequency selective surface. The phase shifter includes a first phase shifter and a second phase shifter, where a cavity of the first phase shifter is disposed at the first side edge, and a cavity of the second phase shifter is disposed at the second side edge. A first frequency band radiation element includes a first array and a second array. The first phase shifter is connected to the first array, and is configured to feed the first array. The second phase shifter is connected to the second array, and is configured to feed the second array.
The phase shifter further includes a phase shift circuit, and the phase shift circuit is disposed at the cavity. A radiation element of the first frequency band radiation element array includes a first balun, and the first balun includes a first outer conductor and a first inner conductor. The radiation element of the first frequency band radiation element array includes a first radiation arm and a second radiation arm that are co-polarized. The first outer conductor is connected to the first radiation arm and the cavity, and the first inner conductor is connected to the second radiation arm and the phase shift circuit. In other words, the first radiation arm is connected to the cavity via the first outer conductor, and the second radiation arm is connected to the phase shift circuit via the first inner conductor. In this solution, the first balun is directly electrically connected to the phase shifter. In this solution, there is no need to use the frequency selective surface to transfer a signal between the first balun and the phase shifter. A transmission path of the signal is short. In this case, an insertion loss of the signal is small. This helps improve a gain of the first frequency band radiation element array, and improve performance of the antenna system. In addition, in this solution, there is no need to use the frequency selective surface to transfer the signal between the first balun and the phase shifter. In this case, interference of the frequency selective surface to the second frequency band radiation element array is small. This helps improve a gain of the second frequency band radiation element array, and can also improve the performance of the antenna system.
The radiation element of the first frequency band radiation element array may include a group of a first radiation arm and a second radiation arm that are co-polarized, or may include two groups of first radiation arms and second radiation arms that are co-polarized, and each group has a different polarization direction. This is not limited in this disclosure.
When the first balun is disposed, an included angle between the first balun and the frequency selective surface may be an acute angle. In other words, the first balun is inclined toward a center of the frequency selective surface. According to this solution, a projection of the first frequency band radiation element array on the frequency selective surface may be completely located on the frequency selective surface. In this solution, the frequency selective surface may completely reflect the signal of the first frequency band radiation element array, to improve the gain of the first frequency band radiation element array.
For the second frequency band radiation element array located on a rear side of the frequency selective surface, a projection of the second frequency band radiation element array on the frequency selective surface may be completely located on the frequency selective surface, or may be partially located on the frequency selective surface. This is not limited in this disclosure.
The antenna system may further include a reflection plate. The reflection plate is disposed on a side that is of the second frequency band radiation element array and that is away from the frequency selective surface, and is configured to reflect the signal of the second frequency band radiation element array. The signal includes a signal sent to the second frequency band radiation element array and a signal emitted by the second frequency band radiation element array. According to this solution, the gain of the second frequency band radiation element array may be improved.
A length of the cavity in the first extension direction is greater than or equal to a length of the first frequency band radiation element array in the second extension direction. According to this solution, all radiation elements of the first frequency band radiation element array may be directly disposed in the cavity, to reduce a length of a connection structure between the radiation elements and the cavity, reduce the insertion loss, and improve signal quality of the first frequency band radiation element array. In addition, this solution further helps improve overall strength of the antenna system.
The first frequency band radiation element array may be a passive radiation element array. The first frequency band radiation element array does not interfere with the second frequency band radiation element array disposed on the rear side of the frequency selective surface, to implement stacking of the radiation element arrays. The second frequency band radiation element array may be a passive radiation element array or an active radiation element array. This is not limited in this disclosure.
A frequency band of the first frequency band radiation element array is less than a frequency band of the second frequency band radiation element array. A smaller frequency band of a radiation element array indicates a larger size of the radiation element. This solution helps enable a size of a radiation element disposed on a front side of the frequency selective surface to be large among radiation elements of the entire antenna system, so that an appearance of the antenna system is regular, and the wind load of the antenna system may also be small.
When the antenna system in this disclosure is disposed, a radiation surface of the first frequency band radiation element array may be parallel to the frequency selective surface, and a radiation surface of the second frequency band radiation element array may be parallel to the frequency selective surface. In other words, the radiation surface of the first frequency band radiation element array, the radiation surface of the second frequency band radiation element array, and the frequency selective surface are all disposed in parallel. In this case, directions of signal beams emitted and received by the first frequency band radiation element array are the same as directions of signal beams emitted and received by the second frequency band radiation element array. This solution helps improve accuracy of signal coverage of the antenna system.
When the antenna system is disposed, the antenna system may include a first radome and a second radome. The first frequency band radiation element array is disposed in the first radome, and the second frequency band radiation element array is disposed in the second radome. This solution helps implement independent evolution of the first frequency band radiation element array and the second frequency band radiation element array.
When the antenna system is mounted, the first radome has a first mounting structure, and the first radome is fastened or otherwise connected to the second radome to form an integrated structure. The first mounting structure is mounted on a pole, so that the entire antenna system may be mounted on the pole. This solution helps simplify a process of mounting the antenna system.
The second radome may further have a second mounting structure. Both the first mounting structure and the second mounting structure are mounted on the pole. In this solution, the first radome and the second radome may be independently mounted. In this case, a decoupling level between the first frequency band radiation element array and the second frequency band radiation element array is higher, and this better helps implement the independent evolution of the first frequency band radiation element array or the second frequency band radiation element array.
The antenna system further includes a third frequency band radiation element array, and the third frequency band radiation element array and the first frequency band radiation element array are located on a same side of the frequency selective surface. A frequency band of the third frequency band radiation element array is different from the frequency band of the first frequency band radiation element array. In other words, the side that is of the frequency selective surface and on which the first frequency band radiation element array is located may have radiation element arrays in at least two frequency bands.
Except that the frequency band of the third frequency band radiation element array is different from the frequency band of the first frequency band radiation element array, other features of the third frequency band radiation element array may be the same as features of the first frequency band radiation element array. For example, the third frequency band radiation element array is also a passive radiation element array, and the frequency band of the third frequency band radiation element array is also less than the frequency band of the second frequency band radiation element array.
When the third frequency band radiation element array is disposed, both the third frequency band radiation element array and the first frequency band radiation element array may be disposed in the first radome, to simplify a structure of the antenna system.
The antenna system may further include a fourth frequency band radiation element array. The fourth frequency band radiation element array and the second frequency band radiation element array are located on a same side of the frequency selective surface. A frequency band of the fourth frequency band radiation element array is different from the frequency band of the second frequency band radiation element array. In other words, the side that is of the frequency selective surface and on which the second frequency band radiation element array is located may have radiation element arrays in at least two frequency bands.
Except that the frequency band of the fourth frequency band radiation element array is different from the frequency band of the second frequency band radiation element array, other features of the fourth frequency band radiation element array may be the same as features of the second frequency band radiation element array. For example, the frequency band of the fourth frequency band radiation element array is also greater than the frequency band of the first frequency band radiation element array.
When the fourth frequency band radiation element array is disposed, both the fourth frequency band radiation element array and the second frequency band radiation element array may be located in the second radome. Alternatively, in another technical solution, the antenna system further includes a third radome, and the fourth frequency band radiation element array is disposed in the third radome. In this way, radiation element arrays in different frequency bands are disposed in different radomes, to facilitate independent evolution of the second frequency band radiation element array and the fourth frequency band radiation element array.
When the third radome is mounted, the third radome may be fastened or otherwise connected to the first radome, and then mounted on the pole. Alternatively, the third radome may be further provided with a third mounting structure, and the third mounting structure is mounted on the pole. In other words, the fourth frequency band radiation element array may be independently mounted on the pole, to facilitate independent evolution of the fourth frequency band radiation element array.
According to a second aspect, this disclosure further provides a base station antenna feeder system. The base station antenna feeder system includes the antenna system according to the first aspect, and further includes a pole. The antenna system is mounted on the pole. In this solution, the base station antenna feeder system has high integration, antenna signal quality is good. This helps perform independent evolution.
To facilitate understanding of an antenna system and a base station antenna feeder system provided in embodiments of this disclosure, the following describes an application scenario of the antenna system and the base station antenna system. For example, as shown in
The base station may further include a radio frequency processing unit 5 and a baseband processing unit 6. For example, the radio frequency processing unit 5 may be configured to perform frequency selection, amplification, and down-conversion processing on a signal received by the antenna system 1, and convert the signal into an intermediate frequency signal or a baseband signal and send the intermediate frequency signal or the baseband signal to the baseband processing unit 6; or the radio frequency processing unit 5 is configured to perform up-conversion and amplification processing on the baseband processing unit 6 or an intermediate frequency signal, and convert the baseband processing unit 6 and the intermediate frequency signal into an electromagnetic wave and send the electromagnetic wave out over the antenna system 1. The baseband processing unit 6 may be connected to a feeder network of the antenna system 1 via the radio frequency processing unit 5. In some implementations, the radio frequency processing unit 5 may also be referred to as a remote radio unit (RRU), and the baseband processing unit 6 may also be referred to as a baseband unit (BBU).
As shown in
With continuing reference to
In the antenna system 1 of the base station, the radiation element array 12 is connected to a feeder network 14. The feeder network 14 is generally formed by a controlled impedance transmission line. The feeder network 14 may feed a signal to the radiation element array 12 based on a specific amplitude and phase, or send a received signal to the baseband processing unit 6 of the base station based on a specific amplitude and phase. Specifically, in some implementations, the feeder network 14 may implement different radiation beam directions by using a drive part 141, or may be connected to a calibration network 142 to obtain a calibration signal needed by the system. The feeder network 14 may include a phase shifter 143, configured to change a maximum direction of antenna signal radiation. Some modules for performance extension may be further disposed in the feeder network 14, for example, a combiner 144. The combiner 144 may be configured to combine signals with different frequencies into one path and emit the signals by using the antenna system 1. When used in reverse, the combiner 144 may be configured to divide, based on different frequencies, signals received by the antenna system 1 into a plurality of paths and send the signals on the plurality of paths to the baseband processing unit 6 for processing. The modules may be, for another example, a filter 145. The filter 145 is configured to filter out an interference signal.
In a specific embodiment, one phase shifter 143 may include one or more cavities 1431. For example, when the second frequency band radiation element array 122 includes a dual-polarized radiation element, the phase shifter 143 includes two cavities 1431, where the two cavities are configured to be correspondingly connected to one column of second frequency band radiation element arrays 122. In the accompanying drawings of embodiments of this disclosure, an example in which the phase shifter 143 includes one cavity 1431 is used for description. The cavity 1431 may be a cavity 1431 having a closed cross section, or may be a cavity 1431 having a non-closed cross section. The cavity 1431 is configured to form a ground layer of the phase shift circuit 1432 of the phase shifter 143. The phase shift circuit 1432 is disposed at the cavity 1431, and a specific disposition position of the phase shift circuit 1432 is not limited. For example, when the cavity 1431 is the cavity 1431 having the closed cross section, that the phase shift circuit 1432 is disposed at the cavity 1431 may be understood as that the phase shift circuit 1432 may be disposed inside the cavity 1431, or may be disposed on an outer surface of the cavity 1431.
In this embodiment, the cavity 1431 of the phase shifter 143 is disposed at the edge of the FSS 15, and in this case, no structure that may cause interference exists on a surface of the entire FSS 15. When the signal of the second frequency band radiation element array 122 passes through the FSS 15, an insertion loss is small. This helps improve signal quality of the antenna system 1. In addition, when the second frequency band radiation element array 122 is disposed, there is no need to consider interference that is caused by the first frequency band radiation element array 121 to the second frequency band radiation element array 122. This helps implement decoupling between the first frequency band radiation element array 121 and the second frequency band radiation element array 122. In other words, signal interference and the like of the second frequency band radiation element array 122 caused to the first frequency band radiation element array 121 may not be taken into consideration for design and layout of the first frequency band radiation element array 121. Similarly, signal interference and the like of the first frequency band radiation element array 121 caused to the second frequency band radiation element array 122 may not be taken into consideration for design and layout of the second frequency band radiation element array 122, either. In this way, the first frequency band radiation element array 121 and the second frequency band radiation element array 122 are flexibly disposed as required. In addition, in conventional technologies, an FSS and a reflection plate carrying a phase shifter need to be disposed side by side in space of an antenna system that faces an antenna. The reflection plate is configured to carry the phase shifter, and reflect a signal of the first frequency band radiation element array. However, the reflection plate cannot transmit a signal of the second frequency band radiation element array, so that the second frequency band radiation element array cannot be disposed on a side that is of the reflection plate and that is away from the first frequency band radiation element array. Consequently, space for disposing the second frequency band radiation element array is limited. In this embodiment of this disclosure, there is no need to dispose a reflection plate for carrying the phase shifter. In this case, the FSS 15 having a larger area may be disposed. Therefore, there is larger space on a side that is of the FSS 15 and that is away from the first frequency band radiation element array 121, to dispose the second frequency band radiation element array 122. In this way, integration of the antenna system 1 can be improved. In this solution, the first frequency band radiation element array 121 and the second frequency band radiation element array 122 are arranged in the SBS manner, so that radiation element arrays in at least two frequency bands can be deployed on a single antenna. From the perspective of a front direction of the antenna system 1, in other words, in a direction perpendicular to the surface of the FSS 15, the antenna system 1 wholly occupies the antenna, and deployment is easy. In addition, the integration of the antenna system 1 is high, and in this case, an area of the antenna system 1 is small, and wind load is small.
When the antenna system 1 is mounted, a side that is of the second frequency band radiation element array 122 of the antenna system 1 and that is away from the first frequency band radiation element array 121 may be mounted on the pole 2. In other words, the first frequency band radiation element array 121, the FSS 15, and the second frequency band radiation element array 122 are sequentially disposed in a direction facing the pole 2. A direction that is of the FSS 15 and that is away from the pole 2 indicates a front side, and the direction that is of the FSS 15 and that faces the pole 2 indicates a rear side. A signal generated by the first frequency band radiation element array 121 is directly emitted to the front side of the FSS 15, and the FSS 15 may reflect the signal that is generated by the first frequency band radiation element array 121 and that faces the FSS 15. A signal generated by the second frequency band radiation element array 122 may pass through the FSS 15, and may also be emitted to the front side of the FSS 15. In this solution, the cavity 1431 of the phase shifter 143 is disposed at the edge of the FSS 15, and there is no need to additionally arrange the reflection plate for disposing the phase shifter 143. In this way, the FSS 15 having a larger area may be disposed in the antenna system 1, and the space on the side that is of the FSS 15 and that is away from the first frequency band radiation element array 121 is also large. Therefore, there is large space that is for disposing the second frequency band radiation element array 122 and that is on the rear side of the FSS 15, to improve the integration of the antenna system 1.
In a specific embodiment, the cavity 1431 of the phase shifter 143 may be disposed at the edge of the FSS 15. When the antenna system 1 further includes another part, the another part may also be disposed at the edge of the FSS 15.
In this embodiment, a length of the first side edge 151 is greater than a length of the third side edge 153, the cavities 1431 are disposed at the first side edge 151 and the second side edge 152 of the FSS 15, the first frequency band radiation element array 121 extends in the first direction X, and the cavities 1431 also extend in the first direction X.
With continuing reference to
A specific structure of the FSS 15 is not limited in this embodiment, provided that functions of reflecting the signal of the first frequency band radiation element array 121 and transmitting the signal of the second frequency band radiation element array 122 can be implemented. In an embodiment, the FSS 15 may be a grid structure.
With continuing reference to
In this solution, the electrical connection between the first balun 1213 and the phase shifter 143 may be a direct electrical connection, or may be a coupling electrical connection. This is not limited in this disclosure.
Referring to
For the second frequency band radiation element array 122 located on a rear side of the FSS 15, a projection of the second frequency band radiation element array 122 on the FSS 15 may be completely located on the FSS 15, or may be partially located on the FSS 15. This is not limited in this disclosure.
Referring to
Alternatively, in another embodiment, the first balun 1213 may be of a segment structure.
Still referring to
In an embodiment, the second frequency band radiation element array 122 is also connected to a phase shifter. The phase shifter is configured to feed the second frequency band radiation element array 122. A specific disposition position of the phase shifter is not limited in this disclosure. For example, when a reflection plate is disposed on the side that is of the second frequency band radiation element array 122 and that is away from the FSS 15, the phase shifter may be disposed on the reflection plate. Certainly, even if a corresponding reflection plate is not disposed for the second frequency band radiation element array 122, the phase shifter may be mounted by using a mechanical part.
The first frequency band radiation element array 121 may be a passive radiation element array, and the first frequency band radiation element array 121 does not interfere with the second frequency band radiation element array 122 disposed on a rear side of the FSS 15, to implement stacking of radiation element arrays 12. In a specific embodiment, the first frequency band radiation element array 121 may be a fourth generation (4G) low-frequency antenna, and is generally in a frequency band of 690 MHz to 960 MHz. The second frequency band radiation element array 122 may be specifically a passive (Passive) radiation element array or may be an active radiation element array. This is not limited in this disclosure. When the second frequency band radiation element array 122 is the active radiation element array, the second frequency band radiation element array 122 may be a fifth generation (5G) high-frequency antenna, and is generally in a frequency band of 2600 MHz or 3500 MHz. The second frequency band radiation element array 122 may be specifically a massive multiple-input multiple-output (MM) antenna.
In addition, a frequency band of the first frequency band radiation element array 121 may be less than a frequency band of the second frequency band radiation element array 122. Generally, a radiation element array in a smaller frequency band indicates a larger size of a single radiation element. In this solution, a radiation element disposed on a front side of the FSS 15 has a large size in radiation elements of the entire antenna system. Therefore, from the perspective of a direction A in
With continued reference to
Still referring to
As shown in
As shown in
Referring to
When the second frequency band radiation element array 122 and the fourth frequency band radiation element array 124 are disposed, the second frequency band radiation element array 122 and the fourth frequency band radiation element array 124 may be disposed in parallel. More specifically, the second frequency band radiation element array 122 and the fourth frequency band radiation element array 124 may be disposed on a same plane. In this way, when both the second frequency band radiation element array 122 and the fourth frequency band radiation element array 124 are active radiation element arrays, a signal blocking problem does not exist.
The fourth frequency band radiation element array 124 may be a passive radiation element array or an active radiation element array. In a specific embodiment, a frequency band of the fourth frequency band radiation element array 124 may be greater than a frequency band of a first frequency band radiation element array 121. In conclusion, except that the frequency band of the fourth frequency band radiation element array 124 is different from a frequency band of the second frequency band radiation element array 122, other features of the fourth frequency band radiation element array 124 may be the same as features of the second frequency band radiation element array 122 in the foregoing embodiments.
As shown in
Alternatively,
Still referring to
Alternatively,
Alternatively,
It is clear that a person skilled in the art may make various modifications and variations to disclosed embodiments without departing from the protection scope of this disclosure. In this way, this disclosure is intended to cover these modifications and variations thereof, as provided in the accompanying claims.
Number | Date | Country | Kind |
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202111162182.9 | Sep 2021 | CN | national |
This filing is a continuation of International Patent Application No. PCT/CN2022/121392 filed on Sep. 26, 2022, which claims priority to Chinese Patent Application No. 202111162182.9 filed on Sep. 30, 2021. The disclosures of the aforementioned applications are hereby incorporated by reference in their entireties.
Number | Date | Country | |
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Parent | PCT/CN2022/121392 | Sep 2022 | WO |
Child | 18621837 | US |