An embedded broadband vertically polarized multiple-input multiple-output antenna

Abstract

This invention discloses an embedded broadband vertically polarized multiple-input multiple-output antenna. The antenna's multi-port tapered antenna metal structure (1) has a centrally recessed top disk metal structure (1a) at its top, and a tapered branch metal structure (1b) at its lower part. The multi-port tapered antenna metal structure (1) is located within a bowl-shaped metal structure (2). A crescent-shaped slot (3) is located at the bottom of the bowl-shaped metal structure (2). Antenna input / output ports (4) are connected to the lower end of the tapered branch metal structure (1b). A circular dielectric plate (5) is used to fix the multi-port tapered antenna metal structure (1) and the bowl-shaped metal structure (2). Utilizing the structure of this invention, a broadband vertically polarized multiple-input multiple-output radiation characteristic can be achieved, and it has an embedded structure, showing broad application prospects in non-protruding communication systems on various platforms such as vehicles, ships, and aircraft.

Description

Technical Field

[0001] The present invention belongs to the field of electronic devices for wireless communication systems, and specifically relates to an embedded broadband vertically polarized multiple-input multiple-output antenna. The embedded broadband vertically polarized multiple-input multiple-output antenna has an ultra-wide operating frequency band, comprises multiple excitation ports, and when each port is excited individually, can generate a vertically polarized directional radiation pattern within a very wide frequency band, and is suitable for embedded communication systems of various platforms such as vehicles, ships, and aircraft. Background Art

[0002] The continuous development of wireless communication technology and the rapid evolution of highly integrated electronic devices have promoted the diversity of information acquisition methods and information interaction, and also put forward higher requirements for the integration of communication equipment and platforms. In particular, for vehicle-mounted, ship-mounted, and airborne applications, the external structure of the communication equipment needs to be conformal to the external structure of the vehicle, ship, and aircraft. Therefore, high-performance non-protruding antennas and embedded antennas are particularly important.

[0003] Most of the existing communication antennas installed on platforms such as vehicles, ships, and aircraft are protruding devices. The protruding antenna will increase the profile and occupy a lot of space, which will break the original appearance of the platform and bring a series of mechanical, aesthetic, and waterproof problems. In addition, it may also deteriorate the radiation performance of the antenna itself. In previous studies, vertically polarized broadband omnidirectional antennas and vertically polarized broadband MIMO antennas are both protruding and have a high profile, while low-profile vertically polarized broadband omnidirectional antennas and vertically polarized broadband MIMO antennas have very narrow bandwidths. Therefore, the proposal of non-protruding antennas can greatly reduce the profile of antennas by making full use of new structures while ensuring the radiation performance of antennas. The ultra-wide working bandwidth can not only ensure high-speed data transmission, but also cover most frequency band requirements to reduce the number of antennas required for the device. To achieve omnidirectional signal coverage with MIMO antennas in the entire wide communication frequency band, it is generally necessary for several narrow beam antennas to work simultaneously. However, due to the mutual coupling between antenna ports, the overall performance of the antenna is often greatly reduced, resulting in the inability to efficiently utilize the diversified gain brought by MIMO. Therefore, in various communication platforms, it is of great significance to use a single antenna with a non-protruding structure to achieve vertically polarized MIMO radiation characteristics within a wider communication frequency band. Summary of the invention

[0004] Technical problem: In order to solve the problem that the communication equipment required on various platforms can reduce the profile to the greatest extent to maintain the original shape of the platform, and can produce multiple vertically polarized directional radiation patterns in a wide frequency band, the present invention provides an embedded broadband vertically polarized multi-input and multi-output antenna. The antenna is composed of a multi-port gradient antenna metal structure, a bowl-shaped metal structure, a crescent-shaped groove, antenna input and output ports, and a circular dielectric plate. The antenna disk radius is 0.65λ0, the total height is 0.48λ0, λ0 is the free space wavelength of the antenna at 3.95GHz, and the profile is very low. The antenna can support all communication frequency bands within the 1.7-6GHz spectrum, and it includes multiple excitation ports. When each port is excited separately, it can produce a vertically polarized directional radiation pattern in a wide frequency band. In addition, there is good port isolation between each of the multiple excitation ports, and a low envelope correlation coefficient between the radiation fields.

[0005] Technical solution: The present invention proposes an embedded broadband vertically polarized MIMO antenna. The structure is achieved by embedding a multi-port tapered antenna metal structure in a bowl-shaped metal structure; fixing the multi-port tapered antenna metal structure on the bottom metal disk in the bowl-shaped metal structure; four crescent-shaped grooves are engraved on the bottom of the bowl-shaped metal; the antenna input and output ports are connected to the tapered branch lobe metal structure of the multi-port tapered antenna metal structure through the bowl-shaped metal structure; and the multi-port tapered antenna metal structure and the bowl-shaped metal structure are fixed with a circular ring-shaped dielectric plate. This embedded broadband vertically polarized MIMO antenna has a bandwidth of 116%, which can cover all communication frequency bands within the 1.7-6GHz spectrum. When each port is excited separately, it can generate a vertically polarized directional radiation pattern within a very wide frequency band. And the isolation between its two ports is less than -15dB, and the envelope correlation coefficient is less than 0.1. Compared with the existing vertically polarized broadband MIMO antenna, the present invention has the advantages of being able to achieve simultaneous coverage of multiple communication frequency bands, and has the advantages of low port isolation, high efficiency, high gain, low envelope correlation coefficient, and non-protruding structure, and has important prospects in various communication platforms in the future.

[0006] The embedded broadband vertically polarized multi-input and multi-output antenna of the present invention comprises a multi-port gradient antenna metal structure, a bowl-shaped metal structure, a crescent-shaped groove, antenna input and output ports and a circular ring-shaped dielectric plate; wherein, the top of the multi-port gradient antenna metal structure is a top disk metal structure with a center depression, the lower part of the top disk metal structure with a center depression is a gradient branch lobe metal structure, and the multi-port gradient antenna metal structure is located in the bowl-shaped metal structure; the crescent-shaped groove is located at the bottom of the bowl-shaped metal structure; the antenna input and output ports are connected to the lower end of the gradient branch lobe metal structure; and the circular ring-shaped dielectric plate is used to fix the multi-port gradient antenna metal structure and the bowl-shaped metal structure.

[0007] The disk edge of the top disk metal structure with a depression in the center of the multi-port tapered antenna metal structure is aligned with the top outer edge of the tapered branch lobe metal structure.

[0008] Four rectangular radial grooves are engraved on the top disk metal structure with a depression in the center of the multi-port gradient antenna metal structure.

[0009] The multi-port tapered antenna metal structure is fixed on a bottom metal disk on the bowl-shaped metal structure through a central metal cylinder.

[0010] The inner wall of the bowl-shaped metal structure is in an arc shape, the diameter of the inner wall "bowl mouth" is 3.95 to 5 times the wavelength, and the outer diameter of the bowl-shaped metal structure must be larger than the diameter of the inner wall "bowl mouth".

[0011] The number of crescent-shaped grooves etched at the bottom of the bowl-shaped metal structure needs to be equal to the number of the tapered branch lobe metal structures and the number of the antenna input and output ports.

[0012] The number of tapered branch lobe metal structures, the number of crescent-shaped grooves and the number of antenna input and output ports of the multi-port tapered antenna metal structure is four or more.

[0013] The antenna input and output ports are respectively connected to the bottom of the tapered branch lobe metal structure of the multi-port tapered antenna metal structure through a bowl-shaped metal structure.

[0014] The bowl-shaped metal structure can be expanded into a planar metal structure.

[0015] The diameter of the top disk metal structure with a central depression is D0, and radial grooves corresponding to the number of ports are loaded on the edge of the top disk, and the length of the radial grooves is L. s , the width of the radial groove is W s , the value of D0 is 1.25~1.35λ0, L s The value of is 0.25~0.3λ0, W s The value of is 0.02~0.03λ0.

[0016] The diameter of the etched crescent groove is D c , the width of the crescent groove is D m , the distance between the antenna input and output ports and the center is D f , the diameter of the bottom metal disk is D b , D c The value of is 0.5~0.55λ0, D m The value of is 0.03~0.05λ0, D f The value of is 0.2~0.25λ0, D b The value of is 0.05~0.055λ0.

[0017] The height of the top disk metal structure with a central depression is H p , the edge of the branch petal is aligned with the edge of the top disk, and the length of the branch petal metal structure is L b , the diameter of the top disk depression is L d , the height of the top disk depression is H d , H p The value of L is 0.02~0.03λ0, b The value of is 0.3~0.5λ0, L d The value of H is 0.6~0.7λ0, d The value of is 0.05~0.07λ0.

[0018] The length of the horizontal metal plate is L h , the length of the vertical metal plate is L v , the height of the horizontal metal plate is H h , the height of the vertical metal plate is H v , the height of the central circular metal column is H c , L h The value of L is 0.5~0.6λ0, v The value of is 0.06~0.07λ0, H h The value of is 0.075~0.085λ0, H v The value of H is 0.28~0.32λ0, c The value of is 0.35~0.45λ0.

[0019] The inner wall of the bowl-shaped metal structure is an arc-shaped metal structure, the top diameter of the bowl mouth is D1, the bottom diameter of the bowl mouth is D2, and the center diameter of the bowl mouth is D3. The value of D1 is 3.9-4λ0, the value of D2 is 1.45-1.55λ0, and the value of D3 is 0.95-1.25λ0.

[0020] The coaxial waveguide feed line is a 50-ohm coaxial waveguide.

[0021] Beneficial effects: Compared with the prior art, the embedded broadband vertically polarized multiple-input multiple-output antenna provided by the present invention has the following advantages:

[0022] (1) This type of antenna has a wide operating frequency band of 1.65 to 6.25 GHz, which basically covers multiple communication frequency bands below 6 GHz, such as the GSM band, WIFI band, Bluetooth band, some LTE bands, 5G bands, and Internet of Vehicles bands. Therefore, it has a wide range of engineering practicability, greatly reduces the number of antennas, and can be applied to a variety of communication platforms. Compared with the previous vertically polarized broadband antenna and vertically polarized MIMO antenna, this antenna avoids the problem of narrow bandwidth caused by the low profile.

[0023] (2) Compared with the previously widely used protruding antenna, this work proposes an embedded antenna for the first time. Its non-protruding structure will greatly improve the poor space utilization caused by the protruding profile caused by the antenna installation.

[0024] (3) When each port is excited individually, it can produce a vertically polarized directional radiation pattern in a very wide frequency band.

[0025] (4) The antenna has excellent port isolation, efficiency, gain, and very low envelope correlation coefficient within an ultra-wide operating frequency band. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 a shows a front view of the metal structure of the multi-port gradient antenna of the present invention; Figure 1 b shows the top view of the bowl-shaped metal structure; Figure 1 c and Figure 1 d shows a side view of the metal structure of the multi-port gradient antenna of the present invention; Figure 1 e shows a side view of the embedded broadband vertically polarized MIMO antenna of the present invention;

[0027] Figure 2 The S parameters of the embedded broadband vertical polarization MIMO antenna simulation are given;

[0028] Figure 3 The far-field radiation patterns of the embedded broadband vertically polarized multiple-input multiple-output antenna in the elevation xz plane and the azimuth xy plane at each frequency point are given when all ports are excited in phase at the same time; 3a is the pattern at the working frequency of 1.7 GHz, 3b is the pattern at the working frequency of 3.1 GHz, 3c is the pattern at the working frequency of 4.5 GHz, and 3d is the pattern at the working frequency of 5.9 GHz;

[0029] Figure 4 The normalized far-field radiation patterns of the embedded broadband vertically polarized multiple-input multiple-output antenna at each frequency point on the E plane and the H plane when a single port is excited separately are given; wherein 4a is the pattern at the working frequency of 1.7 GHz, 4b is the pattern at the working frequency of 3.1 GHz, 4c is the pattern at the working frequency of 4.5 GHz, and 4d is the pattern at the working frequency of 5.9 GHz;

[0030] Figure 5 The efficiency of the embedded broadband vertically polarized MIMO antenna at all frequencies within the working bandwidth is given;

[0031] Figure 6 The gains of the embedded broadband vertically polarized MIMO antenna at all frequency points within the working bandwidth are given;

[0032] Figure 7 The envelope correlation coefficient between two ports of the embedded broadband vertical polarization multiple-input multiple-output antenna is given;

[0033] Figure 8 a. Figure 8 b. and Figure 8 c shows the front view, top view and side view of the embedded broadband vertical polarization MIMO antenna with six ports. Figure 8 d shows the main view of the bowl-shaped metal structure with six ports.

[0034] Fig. 9 a. Fig. 9 b. and Fig. 9 c shows the front view, top view and side view of the embedded broadband vertical polarization MIMO antenna with eight ports. Fig. 9 d shows the main view of the bowl-shaped metal structure with eight ports;

[0035] The picture includes:

[0036] 1-Multi-port gradient antenna metal structure 2-Bowl-shaped metal structure

[0037] 3 – Crescent-shaped slot 4 – Antenna input and output ports

[0038] 5-Annular dielectric plate

[0039] 1a – Metal structure with a concave top disk 1b – Metal structure with tapered petals

[0040] 1c – Rectangular radial slot 1d – Central metal cylinder

[0041] 2a – Bottom metal disc

[0042] 4a – Antenna input and output port 1 4a – Antenna input and output port 2

[0043] L s – Length W of the radial slot for top disc loading s – Width of radial slot for top disc loading

[0044] D c – Diameter D of the etched crescent groove m – Parallel movement distance of the crescent groove

[0045] D f – The distance D between the antenna input and output ports and the center b – Diameter of the bottom metal disc

[0046] H p – Height L of the top disc metal structure with a central depression b– Length of the metal structure of the branch flap

[0047] L d – Diameter H of the depression on the top disk d – Height of the top disc depression

[0048] L h – Length L of the horizontal metal plate v – Length of vertical metal sheet

[0049] H h – Height H of the horizontal metal plate v – Height of vertical metal sheet

[0050] H c – Height of the central circular metal column

[0051] D0 – Diameter of the top disk metal structure with a depression in the center

[0052] D1 – Diameter of the top of the bowl-shaped metal structure

[0053] D2 – Diameter of the bottom mouth of the “bowl” shaped metal structure

[0054] D3 – The center diameter of the bowl-shaped metal structure DETAILED DESCRIPTION

[0055] The present invention will be further described below in conjunction with the accompanying drawings.

[0056] The embedded broadband vertical polarization MIMO antenna of the present invention comprises a multi-port tapered antenna metal structure 1, a bowl-shaped metal structure 2, a crescent-shaped slot 3, an antenna input / output port 4 and an annular dielectric plate 5. The multi-port tapered antenna metal structure 1 is embedded in the bowl-shaped metal structure 2, and its upper part is a top disk metal structure 1a with a central depression, and its lower part is a tapered branch lobe metal structure 1b; four rectangular radial slots 1c are engraved on the top disk metal structure; the multi-port tapered antenna metal structure 1 is fixed on the bottom metal disk 2a of the bowl-shaped metal structure through the central metal cylinder 1d; and the crescent-shaped slots 3 equal to the number of ports are etched on the bowl-shaped metal structure 2. The inner conductors of the antenna input / output ports 4 are respectively connected to the tapered branch lobe metal structure 1b of the multi-port tapered antenna metal structure 1 through the bowl-shaped metal structure 2, and the outer conductors are respectively connected to the bowl-shaped metal structure 2. The annular dielectric plate 5 is used to stabilize the relative positions of the multi-port tapered antenna metal structure 1 and the bowl-shaped metal structure 2.

[0057] In the design, the diameter D0 of the top disk metal structure of the center depression of the multi-port tapered antenna metal structure 1 and the diameter L of the top disk depression are d , and height H d ,, and the top disk loading radial slot (L s,W s ) determines the lowest resonant frequency of the antenna. The radial grooves loaded on the top disk and the depression in the center are to change the current distribution on the metal structure of the top disk. The resonant frequency is adjusted by controlling the length of the current path to achieve miniaturization of the antenna. In order to produce broadband radiation characteristics, the antenna uses the inherent traveling wave radiation of the gradient metal structure, optimizes the impedance matching of the antenna by controlling the curvature of the gradient structure, and they are aligned with the edges of the top disk metal structure of the center depression. The number of gradient metal structures is unlimited and should correspond to the number of required ports. The central metal cylinder is responsible for connecting the top disk metal structure of the center depression and the bottom metal disk. On the one hand, it plays a supporting role, and on the other hand, the connection with the floor is equivalent to introducing inductance. The central metal cylinders of different thicknesses represent inductors of different sizes, and the central metal cylinder is equivalent to a half-wavelength resonant structure, and its height will also affect the impedance matching of the antenna. When all ports are excited at the same time, the antenna radiates outward along the azimuth plane to form an omnidirectional radiation characteristic.

[0058] For MIMO antennas, the port mutual coupling between channels needs to be as low as possible, generally required to be less than -15dB. In addition, the directional patterns corresponding to different ports also need to have high orthogonality, and this performance can be expressed by the envelope correlation coefficient. For isolation, considering that each port has a common ground, the crosstalk between the coplanar currents on the metal ground is the main factor affecting the mutual coupling between the channels. For the improvement of isolation, the slotted structure is mainly used on the peripheral metal ground to reduce the field coupling and the mutual interference of the current. The number of crescent-shaped grooves corresponding to the number of ports is etched on the bottom metal ground, and a circle of annular grooves is etched around the bottom metal disk so that there is no direct current flow between the ground and the gradient antenna, but only by coupling. Therefore, the ports of the antenna maintain a high isolation in the broadband, and at the same time, the coupling between the radiated electric fields is greatly reduced. Since the inner conductors of the antenna input and output ports are connected to the gradient branch lobe metal structure of the multi-port gradient antenna metal structure through the bowl-shaped metal structure, and it is difficult to connect the antenna input and output ports due to the bending of the bottom of the branch lobe metal structure, it is necessary to extend a section of parallel metal plate to connect to the inner conductor of the antenna input and output ports. In addition, a layer of annular dielectric plate is used on the top of the antenna to fix the metal structure of the multi-port gradient antenna and the bowl-shaped metal structure. Due to the refraction phenomenon, the thickness of the annular dielectric plate will affect the directional radiation pattern when a single port is excited to a certain extent.

[0059] The disk edge of the top disk metal structure with a depression in the center of the multi-port tapered antenna metal structure is aligned with the top outer edge of the tapered branch lobe metal structure. The inner wall of the bowl-shaped metal structure is in an arc shape, the diameter of the inner wall "bowl mouth" is 3.95 to 5 times the wavelength, and the outer diameter of the bowl-shaped metal structure needs to be larger than the diameter of the inner wall "bowl mouth". The number of crescent-shaped grooves etched on the bottom of the bowl-shaped metal structure needs to be equal to the number of tapered branch lobe metal structures and the number of antenna input and output ports. The number of tapered branch lobe metal structures, crescent-shaped grooves and antenna input and output ports of the multi-port tapered antenna metal structure is four or more.

[0060] Figure 1 a shows a front view of the metal structure of the multi-port gradient antenna of the present invention; Figure 1 b shows the top view of the bowl-shaped metal structure; Figure 1 c and Figure 1 d shows a side view of the metal structure of the multi-port tapered antenna of the present invention; Figure 1 e shows a side view of the embedded broadband vertically polarized MIMO antenna of the present invention; the antenna disk radius is 0.65λ0, the total height is 0.48λ0, and λ0 is the free space wavelength of the antenna at an operating frequency of 3.95 GHz.

[0061] Figure 2 The S parameters of the embedded broadband vertically polarized MIMO antenna simulation are given; from the results, it can be concluded that the -10dB impedance bandwidth of the antenna is 1.65–6.25GHz (~116%), and the pairwise isolation of each port within the band is greater than 15dB.

[0062] Figure 3 The normalized far-field radiation patterns of the embedded broadband vertically polarized multiple-input multiple-output antenna at each frequency point in the elevation xz plane and the azimuth xy plane are given when all ports are excited in phase at the same time; 3a is the pattern at the working frequency of 1.7 GHz, 3b is the pattern at the working frequency of 3.1 GHz, 3c is the pattern at the working frequency of 4.5 GHz, and 3d is the pattern at the working frequency of 5.9 GHz; from the results, it can be concluded that the antenna pattern is an omnidirectional pattern on the xy plane and a conical pattern on the xz plane, which confirms that the vertical polarization characteristic can be achieved in the entire working frequency band when all ports are excited simultaneously.

[0063] Figure 4The normalized far-field radiation patterns of the embedded broadband vertically polarized multiple-input multiple-output antenna at each frequency point on the E-plane and the H-plane are given when a single port is excited separately; among them, 4a is the pattern at the working frequency of 1.7 GHz, 4b is the pattern at the working frequency of 3.1 GHz, 4c is the pattern at the working frequency of 4.5 GHz, and 4d is the pattern at the working frequency of 5.9 GHz; from the results, it can be concluded that the antenna pattern on the E-plane is a directional pattern in the range of 30° to 90°. Since the edge of the antenna is close to half a wavelength away from the bowl-shaped metal structure at 1.7 GHz, the low-frequency pattern is slightly toward the normal radiation direction.

[0064] Figure 5 The efficiency of the embedded broadband vertically polarized MIMO antenna at all frequencies is given; it can be concluded from the figure that the efficiency of the antenna is as high as 80% within the working frequency band.

[0065] Figure 6 The gain of the embedded broadband vertically polarized MIMO antenna at all frequencies is given; it can be concluded from the figure that the gain of the antenna is as high as 7dB within the band.

[0066] Figure 7 The envelope correlation coefficient between two ports of the embedded broadband vertically polarized multiple-input multiple-output antenna is given; as can be seen from the figure, the envelope correlation coefficient calculated from the simulated three-dimensional radiation pattern is lower than 0.1 within the operating frequency band. This result confirms that the correlation coefficient between the radiation fields when different ports are excited within the operating frequency band is low, which has met the requirements of the MIMO antenna for channel independence.

[0067] Figure 8 a. Figure 8 b. and Figure 8 c shows the schematic diagrams of the front view, top view and side view of the embedded broadband vertical polarization MIMO antenna with 6 ports, Figure 8 d Schematic diagram of the main view of the bowl-shaped metal structure with 6 ports.

[0068] Fig. 9 a. Fig. 9 b. and Fig. 9 c shows the schematic diagrams of the front view, top view and side view of the embedded broadband vertical polarization MIMO antenna when there are 8 ports. Fig. 9 d Schematic diagram of the main view of the bowl-shaped metal structure with 8 ports.

[0069] In summary, the present invention provides an embedded broadband vertically polarized MIMO antenna, which has a non-protruding structural feature and can realize the vertically polarized directional pattern characteristics within the entire wide frequency band. And when each port is excited individually, it can generate a vertically polarized directional radiation pattern within a very wide frequency band. The antenna can work in an embedded environment, has a wide frequency band, and can have the advantages of vertical polarization characteristics within the band, high radiation efficiency, and low envelope correlation coefficient. It has important application prospects in non-protruding communication platforms, embedded MIMO communication systems, fifth-generation mobile communications and other fields.

[0070] The above is only a preferred embodiment of the present invention. It should be pointed out that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered as the protection scope of the present invention.

Claims

1. An embedded broadband vertically polarized multiple-input multiple-output antenna, characterized in that: The antenna comprises a multi-port tapered antenna metal structure (1), a bowl-shaped metal structure (2), a crescent-shaped groove (3), an antenna input / output port (4) and a circular ring-shaped dielectric plate (5); wherein the top of the multi-port tapered antenna metal structure (1) is a top circular disk metal structure (1a) with a central depression, the bottom of the top circular disk metal structure (1a) with a central depression is a tapered branch lobe metal structure (1b), and the multi-port tapered antenna metal structure (1) is located in the bowl-shaped metal structure (2); the crescent-shaped groove (3) is located at the bottom of the bowl-shaped metal structure (2); the antenna input / output port (4) is connected to the lower end of the tapered branch lobe metal structure (1b); the circular ring-shaped dielectric plate (5) is used to fix the multi-port tapered antenna metal structure (1) and the bowl-shaped metal structure (2); and radial grooves corresponding to the number of antenna input / output ports (4) are loaded on the edge of the top circular disk metal structure (1a); The disc edge of the top disc metal structure (1a) with a recessed center of the multi-port tapered antenna metal structure (1) is aligned with the top outer edge of the tapered branch lobe metal structure (1b); The number of crescent-shaped grooves (3) etched at the bottom of the bowl-shaped metal structure (2) needs to be equal to the number of the gradient branch lobe metal structures (1b) and the number of the antenna input and output ports (4); The number of the tapered branch lobe metal structures (1b) of the multi-port tapered antenna metal structure (1), the number of the crescent-shaped grooves (3) and the antenna input and output ports (4) is four or more.

2. The embedded broadband vertically polarized multiple-input multiple-output antenna according to claim 1, characterized in that: Four rectangular radial grooves (1c) are engraved on the top circular disk metal structure (1a) with a depression in the center of the multi-port gradient antenna metal structure (1).

3. The embedded broadband vertically polarized multiple-input multiple-output antenna according to claim 1, characterized in that: The multi-port tapered antenna metal structure (1) is fixed on a bottom metal disk (2a) on a bowl-shaped metal structure (2) via a central metal cylinder (1d).

4. The embedded broadband vertically polarized multiple-input multiple-output antenna according to claim 1, characterized in that: The inner wall of the bowl-shaped metal structure (2) is in the shape of an arc, the diameter of the inner wall "bowl mouth" is 3.95 to 5 times the wavelength, and the outer diameter of the bowl-shaped metal structure needs to be larger than the diameter of the inner wall "bowl mouth".

5. The embedded broadband vertically polarized multiple-input multiple-output antenna according to claim 1, characterized in that: The antenna input and output ports (4) are respectively connected to the bottom of the tapered branch lobe metal structure (1b) of the multi-port tapered antenna metal structure (1) through the bowl-shaped metal structure (2).

6. The embedded broadband vertically polarized multiple-input multiple-output antenna according to claim 1, characterized in that: The bowl-shaped metal structure (2) can be expanded into a planar metal structure.

Images