CN115911850A

CN115911850A - Multi-beam antenna without beam forming network

Info

Publication number: CN115911850A
Application number: CN202211377699.4A
Authority: CN
Inventors: 郑少勇; 马超骏
Original assignee: Sun Yat Sen University
Current assignee: Sun Yat Sen University
Priority date: 2022-11-04
Filing date: 2022-11-04
Publication date: 2023-04-04

Abstract

The invention discloses a multi-beam antenna without a beam forming network, which comprises an antenna layer, an adhesive layer and a feed layer which are sequentially attached, wherein the antenna layer is provided with a plurality of in-band full-duplex antenna units, the upper surface of the antenna layer is provided with a surface wave suppression unit, the in-band full-duplex antenna units are distributed along the length direction of the antenna layer, the upper surface of the feed layer is provided with a metal floor, the lower surface of the feed layer is provided with a first series feed network and a second series feed network, and the first series feed network and the second series feed network are respectively connected with the in-band full-duplex antenna units through via holes. The invention can respectively generate four radiation beams with different directions, can realize the performance of the multi-beam antenna based on the Butler matrix beam forming network, and can remarkably simplify the structure because the beam forming network is not needed, thereby obviously reducing the size of the whole antenna and being more suitable for the requirement of high integration level of a next generation mobile communication system. The invention is widely applied to the technical field of antennas.

Description

Multi-beam antenna without beam forming network

Technical Field

The invention relates to the technical field of antennas, in particular to a multi-beam antenna without a beam forming network.

Background

With the development of wireless communication technology and the rise of various wireless applications, the demand for mobile communication transmission rates has been increasing explosively. The 5G mobile communication system has the characteristics of high speed, low time delay and large connection, and becomes a basic support for realizing the interconnection of everything in the future. The multi-beam antenna technology is one of the key technologies of the 5G mobile communication system, and can realize spatial coverage by generating a plurality of narrow beams with different directions. The multi-beam antenna can not only improve the gain and compensate the loss of a transmission path, but also realize spatial multiplexing and improve the utilization efficiency of frequency spectrum.

The existing multi-beam antenna is generally divided into two types of realization modes of an active multi-beam antenna and a passive multi-beam antenna. Active multi-beam antennas typically employ phased arrays. The phased array is realized by equipping each antenna unit with an independent radio frequency link, and adjusting the amplitude and the phase of each antenna unit through the radio frequency link, so that the directional change of the synthesized beam is realized. Although the phased array can realize flexible beam regulation, the application of the phased array is limited due to the problems of high hardware cost, large power consumption and the like. The passive multi-beam antenna is mainly realized by different modes such as a passive beam forming network, a lens, a reflective array, a transmissive array and the like. Compared with other modes, the multi-beam antenna based on the passive beam forming network can be manufactured in a planar circuit mode, so that the multi-beam antenna is more miniaturized and is more beneficial to system integration. However, the current passive beam forming network has the disadvantages of overlarge size and the like, and the application scenarios of the antenna are severely limited.

Disclosure of Invention

Aiming at the technical problems of overlarge size and the like in the prior passive beam forming network technology, the invention aims to provide a multi-beam antenna without a beam forming network.

The embodiment of the invention comprises a multi-beam antenna without a beam forming network, which comprises an antenna layer, a bonding layer and a feed layer, wherein the antenna layer, the bonding layer and the feed layer are sequentially attached;

the antenna layer is provided with a plurality of in-band full-duplex antenna units, the upper surface of the antenna layer is provided with a surface wave suppression unit, and the in-band full-duplex antenna units are arranged along the length direction of the antenna layer; the upper surface of the antenna layer is a surface far away from the bonding layer, and the lower surface of the antenna layer is a surface facing the bonding layer;

the upper surface of the feed layer is provided with a metal floor, the lower surface of the feed layer is provided with a first series feed network and a second series feed network, and the first series feed network and the second series feed network are respectively connected with each in-band full-duplex antenna unit through via holes; wherein the upper surface of the feed layer is a surface facing the adhesive layer, and the lower surface of the feed layer is a surface away from the adhesive layer.

Further, the in-band full-duplex antenna unit comprises a folding branch patch and a rectangular patch; the folding branch patch is positioned on the upper surface of the antenna layer, and the rectangular patch is positioned on the lower surface of the antenna layer; and in the same in-band full-duplex antenna unit, the rectangular patch is positioned in the projection range of the folding branch patch.

Furthermore, in the same in-band full-duplex antenna unit, the folded branch patch is connected with the rectangular patch through a group of metallized connection through holes; the metallized connecting via hole penetrates through the antenna layer.

Furthermore, the first series feed network includes a first microstrip line, a plurality of first branch lines are disposed on the first microstrip line, each of the first branch lines corresponds to each of the folded branch patches one to one, a tail end of each of the first branch lines is located in a projection range of the corresponding folded branch patch, and the tail end of each of the first branch lines is connected to the corresponding folded branch patch through a first metalized feed via hole; the first metalized feed via penetrates through the antenna layer, the adhesive layer and the feed layer;

the second series feed network comprises a second microstrip line, a plurality of second branch lines are arranged on the second microstrip line, each second branch line corresponds to each folding branch patch one by one, the tail end of each second branch line is located in the projection range of the corresponding folding branch patch, and the tail end of each second branch line is connected with the corresponding folding branch patch through a second metalized feed through hole; the second metalized feed via penetrates the antenna layer, the adhesive layer, and the feed layer.

Furthermore, a circular area is arranged around a position, which is penetrated by the first metalized feeding through hole or the second metalized feeding through hole, in the upper surface of the feeding layer, the circular area is formed by the missing part of the metal floor, and the circular area and the surrounded first metalized feeding through hole or the surrounded second metalized feeding through hole have a common circle center.

Further, one end of the first microstrip line serves as a first port of the multi-beam antenna, the other end of the first microstrip line serves as a second port of the multi-beam antenna, one end of the second microstrip line serves as a third port of the multi-beam antenna, and the other end of the second microstrip line serves as a fourth port of the multi-beam antenna.

Furthermore, the first series feed network is provided with a plurality of first phase shift units, the second series feed network is provided with a plurality of second phase shift units, the number of the first phase shift units is the same as that of the second phase shift units, and the phase shift characteristics of the first phase shift units are different from those of the second phase shift units.

Furthermore, the first phase shift unit is of a U-shaped structure, and the second phase shift unit is of an M-shaped structure.

Furthermore, the surface wave suppression unit comprises two strip-shaped patches, and each strip-shaped patch is respectively arranged on two sides of each in-band full-duplex antenna unit; each strip-shaped patch extends along the length direction of the antenna layer; each strip-shaped patch is provided with a metalized via array, and the metalized via arrays are arranged along the extending direction of the strip-shaped patch; the metallized via array penetrates through the antenna layer and the adhesive layer, and is connected with the metal floor.

Further, the antenna layer is made of Rogers 5880, the feed layer is made of Rogers 5880, the adhesive layer is made of Rogers4450F, and the adhesive layer is a prepreg.

The beneficial effects of the invention are: in the multi-beam antenna without the beam forming network in the embodiment, two series feed networks with different phase differences are adopted to excite a multi-unit in-band full-duplex antenna array, when signals are input from four ports respectively, the multi-beam antenna can generate four radiation beams with different directions respectively, and the performance is similar to that of the traditional multi-beam antenna based on the Butler matrix beam forming network; however, since no beam forming network is needed, the structure of the multi-beam antenna in the embodiment can be significantly simplified, so that the size of the whole antenna is significantly reduced, and the requirement of high integration of the next generation mobile communication system is met.

Drawings

Fig. 1 is an overall structural diagram of a multi-beam antenna without a beam forming network in the embodiment;

FIG. 2 is a schematic diagram of an embodiment from the upper surface side of an antenna layer;

FIG. 3 is a schematic view from the lower surface side of the antenna layer in the embodiment;

FIG. 4 is a schematic view from the upper surface side of the feed layer in the embodiment;

fig. 5 is a schematic view from the lower surface side of the feeding layer in the present embodiment;

FIG. 6 is a schematic view of an adhesive layer in an embodiment;

FIG. 7 is a diagram illustrating scattering parameters for simulation and testing during excitation of the first port in the embodiment;

FIG. 8 is a schematic diagram of simulated and tested scattering parameters during excitation of the third port in an embodiment;

FIG. 9 is a schematic diagram of simulation and test patterns when the first port to the fourth port are excited respectively in the embodiment;

FIG. 10 is a schematic diagram of simulation and test gains and simulation directivities when the first port and the third port are excited respectively in the embodiment;

FIG. 11 is a diagram illustrating simulation efficiencies when the first port and the third port are separately excited according to an embodiment;

reference numerals:

a-antenna layer; b-an adhesive layer; c-a feed layer; 1-in-band full duplex antenna element; 3-metal floor; 11-folding branch patch; 12a — first feed metalized via; 12 b-second feed metallized via; 13-metallization connection vias; 14-strip patch; 15-an array of metallized vias; 16-rectangular patch; 31-circular area; 310-first series feed network; 311-first phase shift unit; 312 — a first microstrip line; 320 — a second series-feed network; 321-a second phase shift unit; 322 — a second microstrip line; 35-first branch line; 36-second branch line.

Detailed Description

The butler matrix is one of the most widely used passive beamforming networks at present. The traditional butler matrix generally adopts different passive microwave devices for combination, and when different input ends are excited, different gradient phase differences can be obtained at the output end. Taking the most common 4 × 4 butler matrix as an example, it needs to be constructed using four couplers, two cross-junctions, and four phase shifters. Therefore, conventional butler matrix-based multi-beam antennas tend to be oversized, typically greater than 10 λ ² And the application scenes of the antenna are severely limited. Especially in 5G millimeter wave frequency band, the system integration difficulty is obviously promoted due to the overlarge antenna size. Therefore, on the basis of realizing multi-beam performance, simplifying and even eliminating the beam forming network is one of the problems to be solved in the current multi-beam antenna technology.

Based on the above principle, the present embodiment provides a multi-beam antenna without a beam forming network. Referring to fig. 1, a multi-beam antenna without a beam forming network includes an antenna layer (a), an adhesive layer (b), and a feed layer (c).

In this embodiment, a side of the antenna layer (a) away from the adhesive layer (b) (e.g., the side shown in fig. 1) is referred to as an upper surface of the antenna layer (a), and another side of the antenna layer (a), i.e., the side facing the adhesive layer (b), is referred to as a lower surface of the antenna layer (a); the side of the feed layer (c) facing the adhesive layer (b) (e.g., the side shown in fig. 1) is referred to as the upper surface of the feed layer (c), and the other side of the feed layer (c), i.e., the side away from the adhesive layer (b), is referred to as the lower surface of the feed layer (c).

In this embodiment, the material of the antenna layer (a) is Rogers 5880, and the thickness is 0.787mm; the material of the feed layer (c) is Rogers 5880, and the thickness is 0.254mm; the material of the adhesive layer (b) was Rogers4450F and the thickness was 0.1mm. The bonding layer (b) is a prepreg and can play a role in bonding, and the antenna layer (a), the bonding layer (b) and the feed layer (c) are tightly pressed together from top to bottom by adopting a multilayer PCB laminating process.

Fig. 1 is a schematic diagram of an overall structure of a multi-beam antenna without a beam forming network in this embodiment. Referring to fig. 1, an antenna layer (a) is provided with a plurality of in-band full-duplex antenna units (1), a surface wave suppression unit is provided on an upper surface of the antenna layer (a), and the in-band full-duplex antenna units (1) are arranged along a length direction of the antenna layer (a). The upper surface of the feed layer (c) is provided with a metal floor (3), the lower surface of the feed layer (c) is provided with a first series feed network (310) and a second series feed network (320), and the first series feed network (310) and the second series feed network (320) are respectively connected with the in-band full-duplex antenna units (1) through via holes.

Fig. 2 is a schematic view from the upper surface side of the antenna layer (a) in the present embodiment, and fig. 3 is a schematic view from the lower surface side of the antenna layer (a) in the present embodiment. Referring to fig. 2, 4 folded branch patches (11) are manufactured on the upper surface of the antenna layer (a) by adopting a PCB process, and 4 rectangular patches (16) are manufactured on the lower surface of the antenna layer (a) by adopting the PCB process. Referring to fig. 2 and 3, if any one of the folded branch patches (11) is projected to the plane of the antenna layer (a), a rectangular patch (16) is located within the projection range of the folded branch patch (11), that is, each folded branch patch (11) has a corresponding rectangular patch (16), and the folded branch patch (11) and the corresponding rectangular patch (16) form an in-band full-duplex antenna unit (1).

Referring to fig. 1, 2 and 3, the 4 in-band full-duplex antenna elements (1) form a linear array, and the 4 in-band full-duplex antenna elements (1) are arranged along the length of the antenna layer (a). Since the length corresponding to 0.61 λ is 6.5mm when the wavelength is λ at the operating frequency of 28GHz, the center distance between two adjacent in-band full-duplex antenna units (1) can be set to 6.5mm in the present embodiment.

Referring to fig. 2, an array formed by 3 metalized connecting through holes (13) is formed in the center of each folding branch patch (11), the upper ends of the 3 metalized connecting through holes (13) are connected with the folding branch patches (11), and the metalized connecting through holes (13) penetrate through the antenna layer (a). Referring to fig. 3, the lower ends of the 3 metallized connecting vias (13) are connected to the rectangular patches (16) corresponding to the folded stub patches (11). The folding branch patch (11), the 3 metallized connection through holes (13) and the corresponding rectangular patch (16) form a fence-shaped structure integrally, namely an in-band full-duplex antenna unit (1). At the antenna operating frequency near 28GHz, the fence structure can be equivalent to a short circuit, which can enable the folding branch patch (11) to work in a half TM mode ₁₂ Mode(s).

Referring to fig. 1 and 2, the surface wave suppression unit includes two strip patches (14) printed on the upper surface of the antenna layer (a). The two strip-shaped patches (14) are respectively arranged at two sides of each in-band full-duplex antenna unit (1) and extend along the length direction of the antenna layer (a). Each strip patch (14) is provided with a metalized via array (15), and the metalized via arrays (15) are arranged along the extending direction of the strip patch (14). The metalized via array (15) penetrates through the antenna layer (a) and the adhesive layer (b) and extends to be connected with the metal floor (3), so that the surface wave suppression unit is connected with the metal floor (3) through the metalized via array (15). By providing the surface wave suppression means, the surface wave on the upper surface of the antenna layer (a) can be suppressed.

Fig. 4 is a schematic view from the upper surface side of the feeding layer (c) in the present embodiment, and fig. 5 is a schematic view from the lower surface side of the feeding layer (c) in the present embodiment.

Referring to fig. 4, the metal floor (3) is manufactured on the upper surface of the feeding layer (c) through a PCB process. Referring to fig. 5, the lower surface of the feeding layer (c) is formed with a first series feeding network (310) and a second series feeding network (320) through a PCB process.

Referring to fig. 5, a main portion of the first series feed network (310) is a first microstrip line (312), 4 first branch lines (35) are disposed on the first microstrip line (312), each first branch line (35) corresponds to each folded branch patch (11) one by one, and a tail end of each first branch line (35) is located within a projection range of the corresponding folded branch patch (11). For example, if any one of the folded branch patches (11) is projected to the plane of the feeding layer (c), the end of a first branch line (35) is located within the projection range of the folded branch patch (11), that is, each folded branch patch (11) has a corresponding end of the first branch line (35), and the folded branch patch (11) is connected with the corresponding end of the first branch line (35) through a first metalized feeding via hole which sequentially penetrates through the antenna layer (a), the adhesive layer (b) and the feeding layer (c).

Similarly, referring to fig. 5, the main portion of the second series feed network (320) is a second microstrip line (322), 4 second branch lines (36) are disposed on the second microstrip line (322), each second branch line (36) corresponds to each folded branch patch (11) one by one, and the tail end of each second branch line (36) is located within the projection range of the corresponding folded branch patch (11). For example, if any one of the folded branch patches (11) is projected to the plane of the feeding layer (c), the end of a second branch (36) is located within the projection range of the folded branch patch (11), that is, each folded branch patch (11) has a corresponding end of the second branch (36), and the folded branch patch (11) is connected with the corresponding end of the second branch (36) through a second metalized feeding via hole which sequentially penetrates through the antenna layer (a), the adhesive layer (b) and the feeding layer (c).

Referring to fig. 4, a portion of the metal material is removed from the metal floor (3) of the upper surface of the feeding layer (c), thereby forming 8 circular regions (31), the 8 circular regions (31) having the same center as the 4 first feeding metalized vias (12 a) and the 4 second feeding metalized vias (12 b), respectively. By providing the circular area (31) with the same total number of the first feed metalized via (12 a) and the second feed metalized via (12 b), the first feed metalized via (12 a) and the second feed metalized via (12 b) are not directly electrically connected with the metal floor (3), so that signals on the feed layer (c) can be transmitted to the antenna layer (a) to feed the 4 in-band full-duplex antenna units (1), and the in-band full-duplex antenna units (1) are excited to generate radiation.

In this embodiment, one end of the first microstrip line (312) serves as a first port of the multi-beam antenna, the other end of the first microstrip line (312) serves as a second port of the multi-beam antenna, one end of the second microstrip line (322) serves as a third port of the multi-beam antenna, and the other end of the second microstrip line (322) serves as a fourth port of the multi-beam antenna.

In this embodiment, referring to fig. 5, in the 4 first branch lines (35) on the first feed network (310), 1 first phase shift unit (311) is located between each two first branch lines (35), that is, the first feed network (310) has 3 first phase shift units (311) in total. The first phase shift unit (311) adopts a U-shaped structure, and a signal transmission path in the first series feed network (310) is increased, so that a phase shift effect is generated. Due to the symmetrical whole structure of the antenna, in the embodiment, when signals are input from the first port, the phase difference of the signals on the 4 first branch lines (35) is 30 degrees; when a signal is input from the second port, the phase difference of the signals on the 4 first branch lines (35) is-30 °.

In this embodiment, referring to fig. 5, in the 4 second branch lines (36) on the second series-fed network (320), 1 second phase shift unit (321) is located between each two second branch lines (36), that is, the second series-fed network (320) has 3 second phase shift units (321) in total. The second phase shifting unit (321) adopts an M-shaped structure, and a signal transmission path in the second series feed network (320) is added, so that a phase shifting effect is generated. Due to the symmetrical whole structure of the antenna, in the embodiment, when a signal is input from the third port, the phase difference of the signals on the 4 second branch lines (36) is 145 degrees; when a signal is input from the fourth port, the phase difference of the signals on the 4 second branch lines (36) (36) is-145 degrees.

Fig. 6 is a schematic diagram of the adhesive layer (b) in the present embodiment, wherein the circular holes represent the through positions formed in the adhesive layer (b) when the vias such as the first feeding metalized via (12 a), the second feeding metalized via (12 b), and the metalized via array (15) penetrate through the adhesive layer (b).

In this embodiment, the principle of the multi-beam antenna without the beam forming network is as follows: exciting a multi-unit in-band full-duplex antenna array by using two series-feed networks (a first series-feed network (310) and a second series-feed network (320)) with different phase differences, wherein when signals are respectively input from four ports (a first port, a second port, a third port and a fourth port), the multi-beam antenna can respectively generate four radiation beams with different directions, and the performance is similar to that of a traditional multi-beam antenna based on a Butler matrix beam forming network; however, since no beam forming network is needed, the structure of the multi-beam antenna in this embodiment can be significantly simplified, so that the size of the whole antenna is significantly reduced, and the requirement of high integration of the next generation mobile communication system is met.

Fig. 7 and 8 are the curves of the simulated and tested scattering parameters under the excitation of the first port and the third port, respectively, in this embodiment. When the first port is excited, the simulation working frequency band of the antenna is 25.8-29.7 GHz, the test working frequency band is 26-29.8 GHz, and the isolation among the four ports is larger than 13.7dB. When the third port is excited, the simulation working frequency band of the antenna is 26.2-29.5 GHz, the testing working frequency band of the antenna is 26.7-30 GHz, and the isolation between the four ports is larger than 12dB. The whole overlapping bandwidth of the antenna is 26.7-29.8 GHz.

Fig. 9 is a graph of simulation and test patterns under the condition that the first port to the fourth port are excited respectively in the present embodiment. When the first port to the fourth port are excited respectively, the simulated beam directions of the antenna are respectively-12 degrees, 28 degrees and-29 degrees, and the test beam directions of the antenna are respectively-13 degrees, 30 degrees and-30 degrees.

Fig. 10 is a simulated and tested gain curve and a simulated directivity curve under the excitation of the first port and the third port in this embodiment. The maximum simulated gain of the antenna is 11.43dBi, and the maximum test gain of the antenna is 11.58dBi. The highest radiation efficiency of the antenna in the working frequency band is 85.6%.

FIG. 11 shows the simulation efficiency when the first port and the third port are separately excited in the embodiment.

From the simulation results shown in fig. 7 to 11, it can be confirmed that the multi-beam antenna without the beam forming network in the present embodiment has good performance.

It should be noted that, unless otherwise specified, when a feature is referred to as being "fixed" or "connected" to another feature, it may be directly fixed or connected to the other feature or indirectly fixed or connected to the other feature. Furthermore, the descriptions of upper, lower, left, right, etc. used in the present disclosure are only relative to the mutual positional relationship of the constituent parts of the present disclosure in the drawings. As used in this disclosure, the singular forms "a", "an", and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. In addition, unless defined otherwise, all technical and scientific terms used in this example have the same meaning as commonly understood by one of ordinary skill in the art. The terminology used in the description of the embodiments herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used in this embodiment, the term "and/or" includes any combination of one or more of the associated listed items.

It will be understood that, although the terms first, second, third, etc. may be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element of the same type from another. For example, a first element could be termed a second element, and, similarly, a second element could be termed a first element, without departing from the scope of the present disclosure. The use of any and all examples, or exemplary language ("e.g.," such as "etc.), provided with the present embodiment is intended merely to better illuminate embodiments of the invention and does not pose a limitation on the scope of the invention unless otherwise claimed.

It should be recognized that embodiments of the present invention can be realized and implemented by computer hardware, a combination of hardware and software, or by computer instructions stored in a non-transitory computer readable memory. The methods may be implemented in a computer program using standard programming techniques, including a non-transitory computer-readable storage medium configured with the computer program, where the storage medium so configured causes a computer to operate in a specific and predefined manner, according to the methods and figures described in the detailed description. Each program may be implemented in a high level procedural or object oriented programming language to communicate with a computer system. However, the program(s) can be implemented in assembly or machine language, if desired. In any case, the language may be a compiled or interpreted language. Furthermore, the program can be run on a programmed application specific integrated circuit for this purpose.

Further, operations of processes described in this embodiment can be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context. The processes described by the present embodiments (or variations and/or combinations thereof) may be performed under the control of one or more computer systems configured with executable instructions and may be implemented as code (e.g., executable instructions, one or more computer programs, or one or more applications) collectively executed on one or more processors, by hardware, or combinations thereof. The computer program includes a plurality of instructions executable by one or more processors.

Further, the method may be implemented in any type of computing platform operatively connected to a suitable interface, including but not limited to a personal computer, mini computer, mainframe, workstation, networked or distributed computing environment, separate or integrated computer platform, or in communication with a charged particle tool or other imaging device, and the like. Aspects of the invention may be embodied in machine-readable code stored on a non-transitory storage medium or device, whether removable or integrated into a computing platform, such as a hard disk, optically read and/or write storage medium, RAM, ROM, or the like, such that it may be read by a programmable computer, which when read by the storage medium or device, is operative to configure and operate the computer to perform the procedures described herein. Further, the machine-readable code, or portions thereof, may be transmitted over a wired or wireless network. The invention described in this embodiment includes these and other different types of non-transitory computer-readable storage media when such media includes instructions or programs that implement the steps described above in conjunction with a microprocessor or other data processor. The invention also includes the computer itself when programmed according to the methods and techniques described herein.

A computer program can be applied to input data to perform the functions described in the present embodiment to convert the input data to generate output data that is stored to a non-volatile memory. The output information may also be applied to one or more output devices, such as a display. In a preferred embodiment of the invention, the transformed data represents physical and tangible objects, including particular visual depictions of physical and tangible objects produced on a display.

The present invention is not limited to the above embodiments, and any modifications, equivalent substitutions, improvements, etc. within the spirit and principle of the present invention should be included in the protection scope of the present invention as long as the technical effects of the present invention are achieved by the same means. The invention is capable of other modifications and variations in its technical solution and/or its implementation, within the scope of protection of the invention.

Claims

1. The multi-beam antenna without the beam forming network is characterized by comprising an antenna layer, an adhesive layer and a feed layer, wherein the antenna layer, the adhesive layer and the feed layer are sequentially attached;

the antenna layer is provided with a plurality of in-band full-duplex antenna units, the upper surface of the antenna layer is provided with a surface wave suppression unit, and the in-band full-duplex antenna units are distributed along the length direction of the antenna layer; the upper surface of the antenna layer is a surface far away from the bonding layer, and the lower surface of the antenna layer is a surface facing the bonding layer;

2. The multiple beam antenna without a beamforming network of claim 1, wherein the in-band full-duplex antenna element comprises a folded stub patch and a rectangular patch; the folding branch patch is positioned on the upper surface of the antenna layer, and the rectangular patch is positioned on the lower surface of the antenna layer; and in the same in-band full-duplex antenna unit, the rectangular patch is positioned in the projection range of the folding branch patch.

3. The multi-beam antenna without a beamforming network of claim 2, wherein the folded stub patch and the rectangular patch are connected by a set of metallized connecting vias in the same in-band full-duplex antenna unit; the metallized connecting via hole penetrates through the antenna layer.

4. The multi-beam antenna without a beamforming network of claim 2, wherein:

the first series feed network comprises a first microstrip line, a plurality of first branch lines are arranged on the first microstrip line, each first branch line corresponds to each folding branch patch one by one, the tail end of each first branch line is located in the projection range of the corresponding folding branch patch, and the tail end of each first branch line is connected with the corresponding folding branch patch through a first metalized feed through hole; the first metalized feed via penetrates through the antenna layer, the adhesive layer and the feed layer;

the second series feed network comprises a second microstrip line, a plurality of second branch lines are arranged on the second microstrip line, each second branch line corresponds to each folding branch patch one by one, the tail end of each second branch line is located in the projection range of the corresponding folding branch patch, and the tail end of each second branch line is connected with the corresponding folding branch patch through a second metalized feed through hole; the second metallized feed via penetrates the antenna layer, the adhesive layer, and the feed layer.

5. The multiple beam antenna without a beamforming network of claim 4, wherein a circular area is provided around a location in the upper surface of the feed layer traversed by the first or second metalized feed via, the circular area being formed by the absence of the metal floor portion, the circular area having a common center with the surrounded first or second metalized feed via.

6. The multi-beam antenna without a beamforming network of claim 4, wherein one end of the first microstrip serves as a first port of the multi-beam antenna, the other end of the first microstrip serves as a second port of the multi-beam antenna, one end of the second microstrip serves as a third port of the multi-beam antenna, and the other end of the second microstrip serves as a fourth port of the multi-beam antenna.

7. The multi-beam antenna without a beamforming network of claim 1, wherein the first series feed network is provided with a plurality of first phase shifting units, the second series feed network is provided with a plurality of second phase shifting units, the number of the first phase shifting units is the same as the number of the second phase shifting units, and the phase shifting characteristics of the first phase shifting units are different from the phase shifting characteristics of the second phase shifting units.

8. The multiple-beam antenna without a beamforming network of claim 7, wherein the first phase shifting unit is U-shaped and the second phase shifting unit is M-shaped.

9. The multiple-beam antenna without a beamforming network of claim 1, wherein the surface wave suppression unit comprises two strip patches, each strip patch being disposed on both sides of each in-band full-duplex antenna unit; each strip-shaped patch extends along the length direction of the antenna layer; each strip-shaped patch is provided with a metalized via array, and the metalized via arrays are arranged along the extending direction of the strip-shaped patch; the metallized via array penetrates through the antenna layer and the adhesive layer, and is connected with the metal floor.

10. The multiple beam antenna without a beamforming network according to any of claims 1 to 9, wherein the material of the antenna layer is Rogers 5880, the material of the feed layer is Rogers 5880, the material of the adhesive layer is Rogers4450F, and the adhesive layer is a prepreg.