High-isolation broadband four-port dual-polarized antenna based on differential and common modes and communication terminal

Abstract

The invention discloses a high-isolation broadband four-port dual-polarized antenna based on differential and common modes and a communication terminal. Comprising a feed layer, a lower dielectric layer, a metal floor, an air layer, an upper dielectric layer and a radiation patch which are stacked in sequence. The feed layer is located on the lower surface of the lower dielectric layer and comprises a feed connector, a micro-strip feeder line, a lumped capacitor, a lumped inductor, a feed metal column and a short circuit metal column. The metal floor is located on the upper surface of the lower dielectric layer, and a plurality of circular gaps concentric with the feed metal columns are etched in the metal floor. The radiation patch is located on the upper surface of the upper dielectric layer, is composed of a horizontal rectangular metal, a vertical rectangular metal and an inclined metal branch, and is used for improving the isolation between different feed ports. The antenna has the characteristics of simple structure, wide band, high isolation and dual polarization, and is suitable for application scenes such as multiple-input-multiple-output (MIMO) systems, radars, satellites and base stations.

Description

Technical Field

[0001] This invention relates to a high-isolation broadband four-port dual-polarized antenna and a communication terminal based on differential common-mode, belonging to the field of antenna design technology. Background Technology

[0002] The introduction of Multiple-Input Multiple-Output (MIMO) technology has improved channel capacity and data transmission rates. However, the strong mutual coupling between the multiple ports of MIMO antennas leads to adverse effects such as poor channel independence, reduced antenna efficiency, decreased gain, and pattern distortion. Current mutual coupling suppression methods are typically applied between multiple antenna elements, inevitably increasing the size of the antenna system. Therefore, research on decoupling techniques for single-radiator antennas with multiple ports has promising applications. Furthermore, dual-polarized antennas can effectively combat Rayleigh fading, improve spectral efficiency, and enhance channel capacity, thus finding widespread application in MIMO systems, radar, satellites, and base stations.

[0003] In the prior art, application document CN202320474214.7 discloses a method to improve port isolation by loading a decoupling structure with metal material between two antennas; application document CN202310273342.X discloses a self-decoupling high isolation MIMO antenna and communication device; the above antennas have problems such as narrow band, multiple radiators, and large size. Summary of the Invention

[0004] The technical problem solved by the present invention is to overcome the shortcomings of the prior art and provide a high-isolation broadband four-port dual-polarized antenna and communication terminal based on differential common mode, which suppresses the mutual coupling between multiple ports.

[0005] The technical solution of this invention is:

[0006] This invention discloses a high-isolation broadband four-port dual-polarized antenna based on differential common mode, comprising a feed layer, a lower dielectric layer, a metal ground plane, an air layer, an upper dielectric layer, and a radiating patch stacked sequentially.

[0007] The upper dielectric layer and the lower dielectric layer are separated by the air layer; the upper dielectric layer is used for printing radiation patches, and the lower dielectric layer is used for printing a metal floor and a power supply layer;

[0008] The feed layer is located on the lower surface of the underlying dielectric layer;

[0009] The feed layer includes a feed connector, a microstrip feed line, a first lumped capacitor, a second lumped capacitor, a lumped inductor, a feed metal pillar, and a short-circuit metal pillar; wherein,

[0010] The power supply connector is located at the edge of the lower dielectric layer;

[0011] The two ends of the microstrip feeder are connected to a feed connector and a feed metal post, respectively.

[0012] The feeding metal pillar passes through the lower dielectric layer, the air layer and the upper dielectric layer and is connected to the radiative patch to excite the radiative patch;

[0013] The microstrip feed line is connected in parallel with the first lumped capacitor, in series with the lumped inductor, and then in parallel with the second lumped capacitor, starting from the end of the feeding metal pillar, in order to achieve impedance matching and extend the operating bandwidth.

[0014] A short-circuit metal post is installed at the end of the microstrip feed line where the first and second lumped capacitors are located, connecting it to the metal ground plane to form a short circuit.

[0015] Furthermore, in the above-mentioned antenna, the metal ground plane is located on the upper surface of the lower dielectric layer, and multiple circular slots concentric with the feed metal pillars are etched on the metal ground plane. The diameter of the circular slots is larger than the diameter of the feed metal pillars, so as not to cause a feed short circuit.

[0016] Furthermore, in the above-mentioned antenna, the radiating patch is located on the upper surface of the upper dielectric layer. The radiating patch includes horizontal rectangular metal, vertical rectangular metal, and oblique metal branches. The horizontal rectangular metal and vertical rectangular metal are orthogonal, and the oblique metal branches intersect with the rectangular metal and vertical rectangular metal, which is used to improve the isolation between different feed ports.

[0017] Furthermore, in the above-mentioned antenna, the length of the horizontal rectangular metal is equal to the length of the vertical rectangular metal, and the width of the horizontal rectangular metal is equal to the width of the vertical rectangular metal.

[0018] Furthermore, in the above-mentioned antenna, the outer diameters of the lower dielectric layer and the metal ground plane are equal.

[0019] Furthermore, in the above-mentioned antenna, the length of the oblique metal stub is less than the length of the horizontal rectangular metal and the length of the vertical rectangular metal, and the width of the oblique metal stub is less than the width of the horizontal rectangular metal and the width of the vertical rectangular metal.

[0020] Furthermore, in the above antenna, the diameter of the feed metal post is smaller than the width of the horizontal rectangular metal post, and also smaller than the width of the microstrip feed line.

[0021] Furthermore, in the above antenna, the diameter of the circular slot is larger than the diameter of the feed metal post; the diameter of the short-circuit metal post is smaller than the width of the microstrip feed line; and the outer diameters of the upper dielectric layer and the radiating patch are equal.

[0022] Furthermore, in the above antenna, the wiring paths of the four sets of microstrip feed lines are centrally symmetrically distributed on the horizontal plane, and the main extension directions of adjacent microstrip feed lines are orthogonal.

[0023] This invention discloses a wireless communication terminal that integrates at least one high-isolation broadband four-port dual-polarized antenna based on differential common mode.

[0024] The advantages of this invention over the prior art are as follows:

[0025] (1) The present invention provides a broadband, high isolation, dual-polarized four-port antenna, which suppresses the mutual coupling between multiple ports based on the common-mode and differential-mode analysis idea, and has the characteristics of simple structure, broadband and dual polarization.

[0026] (2) This invention achieves coupling suppression between dual-polarized ports and co-polarized ports, and achieves close impedance of common mode and differential mode by designing a radiating patch; by loading microstrip feed lines and lumped elements, the antenna impedance is improved and broadband operation of the antenna is realized.

[0027] (3) Compared with the prior art, the present invention effectively weakens the electromagnetic coupling interference between the four ports by using theoretical analysis and structural design, and at the same time has the characteristics of dual polarization, which greatly improves the isolation performance of the four-port antenna.

[0028] (4) In this invention, horizontal and vertical rectangular metals are set on the upper surface of the upper dielectric layer as antenna radiating patches. The length directions of the horizontal and vertical rectangular metals are orthogonal to each other, and the polarized waves radiated into space are orthogonal to each other, which is beneficial to achieving high isolation and dual polarization characteristics.

[0029] (5) In this invention, the radiating patch is excited by loading four feeding metal pillars between the end of the microstrip feed line and the radiating patch. The independent feeding structure at the four ports can significantly improve the dual polarization characteristics of the antenna. With appropriate feeding configuration, independent control of horizontal and vertical polarization can be achieved. This design enables the antenna to have good dual polarization performance within the operating frequency band.

[0030] (6) In this invention, the impedance curves of the differential mode and common mode at different ports are controlled by adjusting the length of the oblique metal branch loaded between the horizontal rectangular metal and the vertical rectangular metal, so that the two are close in value. After the common mode and differential mode are superimposed, the generation of coupling current at the four ports can be suppressed, thereby improving the isolation performance of the antenna.

[0031] (7) In this invention, by adjusting the length and width of the oblique metal stubs, the impedance curves of different ports can be brought closer to the matching point, thereby improving the impedance matching of the antenna and widening the working frequency band of the antenna.

[0032] (8) In view of the problem of narrow bandwidth of existing four-port antennas, the present invention provides a microstrip feed line on the lower surface of the lower dielectric layer, and loads a parallel capacitor and a series inductor on the microstrip feed line. The end of the parallel stub loaded with the parallel capacitor is connected to the metal ground plane through a short-circuit metal post. A "∏" type matching circuit composed of two parallel capacitors and one series inductor is introduced. This circuit can excite a new LC resonance to achieve dual resonance within the frequency band. While maintaining the high isolation characteristics of the four ports, the impedance matching performance of the antenna is improved, thereby widening the operating frequency band of the antenna.

[0033] (9) In order to reduce the coupling interference between adjacent ports, the feeding structure of the four ports is exactly the same and rotates symmetrically around the antenna center in sequence. The main length directions of the microstrip feed lines of adjacent ports are orthogonal to each other in the horizontal plane, which improves the isolation performance of the four-port antenna.

[0034] (10) This invention achieves coupling suppression between dual-polarized and co-polarized ports by loading metal stubs and optimizing the feed structure, thereby improving the impedance matching of the antenna, expanding the operating bandwidth, and significantly increasing the isolation between ports. The antenna features a simple structure, wide bandwidth, high isolation, and dual polarization, making it suitable for applications such as multiple-input multiple-output (MIMO) systems, radar, satellites, and base stations. Attached Figure Description

[0035] Figure 1 This is a top view of a high-isolation broadband four-port dual-polarized antenna based on differential common-mode according to the present invention;

[0036] Figure 2 This is a bottom view of a high-isolation broadband four-port dual-polarized antenna based on differential common-mode according to the present invention;

[0037] Figure 3 This is a schematic cross-sectional view of a high-isolation broadband four-port dual-polarized antenna based on differential common-mode according to the present invention.

[0038] Figure 4 This is a simulated return loss curve of a high-isolation broadband four-port dual-polarized antenna based on differential common mode according to the present invention.

[0039] Figure 5 These are the radiation patterns of the XOZ and YOZ planes at the center frequency during the simulation of the left port of the present invention; (a) is the XOZ plane radiation pattern of the left port of a high-isolation broadband four-port dual-polarized antenna based on differential common mode at 4.59 GHz; (b) is the YOZ plane radiation pattern of the left port of a broadband dual-frequency omnidirectional microstrip antenna of the present invention at 4.59 GHz.

[0040] Figure 6These are the XOZ and YOZ plane radiation patterns of the center frequency during the simulation of the lower port of the present invention; (a) is the XOZ plane radiation pattern of the center frequency during the simulation of the lower port; (b) is the YOZ plane radiation pattern of the center frequency during the simulation of the lower port.

[0041] Figure 7 This is a simulated peak gain curve of a high-isolation broadband four-port dual-polarized antenna based on differential common mode according to the present invention.

[0042] in, Figures 1 to 3 In the diagram, 1-radiating patch, 11-horizontal rectangular metal, 12-vertical rectangular metal, 13-oblique metal stub, 2-upper dielectric layer, 3-metal ground plane, 4-lower dielectric layer, 5-microstrip feeder, 51-parallel lumped element, 52-series lumped element, 6-feed metal pillar, 7-short-circuit metal pillar, 8-air layer. Detailed Implementation

[0043] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0044] like Figure 1 As shown, the present invention discloses a high-isolation broadband four-port dual-polarized antenna based on differential common mode, comprising a feed layer, a lower dielectric layer 4, a metal ground plane 3, an air layer 8, an upper dielectric layer 2, and a radiating patch 1 stacked sequentially.

[0045] The upper dielectric layer 2 and the lower dielectric layer 4 are separated by the air layer 8; the upper dielectric layer 2 is used to print the radiation patch 1, and the lower dielectric layer 4 is used to print the metal floor 3 and the power supply layer;

[0046] The feed layer is located on the lower surface of the lower dielectric layer;

[0047] The feed layer includes a feed connector, a microstrip feed line 5, a first lumped capacitor 51, a second lumped capacitor 51', a lumped inductor 52, a feed metal pillar 6, and a short-circuit metal pillar 7; wherein,

[0048] The power supply connector is located at the edge of the lower dielectric layer 4;

[0049] The two ends of the microstrip feeder 5 are connected to the feed connector and the feed metal post 6, respectively;

[0050] The feeding metal pillar 6 passes through the lower dielectric layer 4, the air layer 8 and the upper dielectric layer 2 and is connected to the radiation patch 1 to excite the radiation patch 1.

[0051] Starting from the end of the feeding metal post 6, the microstrip feed line 5 is connected in parallel with the first lumped capacitor 51, in series with the lumped inductor 52, and then in parallel with the second lumped capacitor 51' to achieve impedance matching and extend the operating bandwidth.

[0052] A short-circuit metal post 7 is installed at the end of the microstrip feed line 5 where the first collective capacitor 51 and the second collective capacitor 51' are located, and connected to the metal ground plane 3 to form a short circuit.

[0053] Preferably, the metal floor 3 is located on the upper surface of the lower dielectric layer 4, and a plurality of circular gaps concentric with the power supply metal pillar 6 are etched on the metal floor 3. The diameter of the circular gaps is larger than the diameter of the power supply metal pillar 6, so as not to cause a power supply short circuit.

[0054] Preferably, the radiating patch 1 is located on the upper surface of the upper dielectric layer 1. The radiating patch 1 includes a horizontal rectangular metal 11, a vertical rectangular metal 12, and an oblique metal branch 13. The horizontal rectangular metal 11 and the vertical rectangular metal 12 are orthogonal, and the oblique metal branch 13 intersects with the rectangular metal 11 and the vertical rectangular metal 12, which is used to improve the isolation between different power supply ports.

[0055] Preferably, the length of the horizontal rectangular metal 11 is equal to the length of the vertical rectangular metal 12, and the width of the horizontal rectangular metal 11 is equal to the width of the vertical rectangular metal 12.

[0056] Preferably, the outer diameters of the lower dielectric layer 4 and the metal floor 3 are equal.

[0057] Preferably, the length of the oblique metal branch 13 is less than the length of the horizontal rectangular metal 11 and the length of the vertical rectangular metal 12, and the width of the oblique metal branch 13 is less than the width of the horizontal rectangular metal 11 and the width of the vertical rectangular metal 12.

[0058] Preferably, the diameter of the feed metal column 6 is smaller than the width of the horizontal rectangular metal 11, and also smaller than the width of the microstrip feed line 5.

[0059] Preferably, the diameter of the circular slit is larger than the diameter of the feeding metal post 6; the diameter of the short-circuit metal post 7 is smaller than the width of the microstrip feed line 5; and the outer diameters of the upper dielectric layer 2 and the radiating patch 1 are equal.

[0060] Preferably, the wiring paths of the four sets of microstrip feed lines 5 are centrally symmetrically distributed on the horizontal plane, and the main extension directions of adjacent microstrip feed lines 5 are orthogonal.

[0061] This invention discloses a wireless communication terminal that integrates at least one high-isolation broadband four-port dual-polarized antenna based on differential common mode.

[0062] Example

[0063] This embodiment provides a high-isolation broadband four-port dual-polarized antenna based on differential common mode, comprising a feed layer, a lower dielectric layer, a metal ground plane, an air layer, an upper dielectric layer, and a radiating patch stacked sequentially.

[0064] The feed layer is located on the lower surface of the lower dielectric layer and includes a feed connector, a microstrip feed line, a lumped element connected in series on the feed line, and a metal pillar. The feed connector is located at the edge of the lower dielectric layer and includes four connectors. The microstrip feed line includes four sets and is rotationally symmetrical. The two ends of the feed line are connected to the feed probe and the feed metal pillar, respectively. The feed metal pillar passes through the lower dielectric layer, the air layer, and the upper dielectric layer and connects to the radiating patch to excite the antenna. From the feed end, the microstrip feed line has a lumped capacitor connected in parallel, a lumped inductor connected in series, and a lumped capacitor connected in parallel. The end of the feed line where the lumped element is located is equipped with a short-circuit metal pillar connected to the metal ground plane to achieve a short-circuit effect.

[0065] The metal floor is located on the upper surface of the lower dielectric layer, and four circular slots are etched on it, concentric with the metal pillars of the feed layer, so that the metal pillars can pass through without causing a short circuit.

[0066] The radiating patch is located on the upper surface of the upper dielectric layer and is composed of horizontal rectangular metal, vertical rectangular metal, and oblique metal stubs. The oblique metal stubs are used to adjust the common-mode and differential-mode impedance of the antenna, thereby improving the isolation between multiple ports.

[0067] The upper dielectric layer and the lower dielectric layer are separated by the air layer.

[0068] The outer diameters of the lower dielectric layer and the metal floor are equal.

[0069] The length of the horizontal rectangular metal is equal to the length of the vertical rectangular metal, and the width of the horizontal rectangular metal is equal to the width of the vertical rectangular metal.

[0070] The length of the oblique metal branch is less than the length of the horizontal rectangular metal and the length of the vertical rectangular metal, and the width of the oblique metal branch is less than the width of the horizontal rectangular metal and the width of the vertical rectangular metal.

[0071] The diameter of the power supply metal column is smaller than the width of the horizontal rectangular metal column, and also smaller than the width of the feed line.

[0072] The diameter of the circular slit is larger than the diameter of the power-feeding metal column.

[0073] The diameter of the short-circuit metal post is smaller than the width of the feed line.

[0074] The outer diameters of the upper dielectric layer and the radiation patch are equal.

[0075] The thickness of the lower dielectric layer is H1, the thickness of the upper dielectric layer is H2, and the two dielectric constants are ε. rThe dielectric layer is separated by an air layer of height H3; where 0≤H1≤0.03λ0, 0≤H2≤0.03λ, 0.06λ0<H3<0.01λ0; and the center frequency of the antenna operating band has a free space wavelength of λ0.

[0076] The outer diameter of the lower dielectric layer is L2, and the outer diameter of the upper dielectric layer is L2, wherein 0.78λ0≤L1, 0.75λ0≤L2≤0.8λ0;

[0077] The length of the horizontal rectangular metal is L4 and the width is W4; the length of the horizontal rectangular metal is L5 and the width is W5; wherein, 0.75λ0≤L4≤0.8λ0, 0.01λ0≤W4≤0.05λ0, 0.55λ0≤L5≤0.7λ0, 0.001λ0≤W5≤0.02λ0;

[0078] The diameter of the power supply metal post is R1, and the diameter of the short-circuit metal post is R2; wherein, R1 < 0.01λ0, R2 < 0.01λ0;

[0079] The capacitance range of the first set of total capacitors 51 and the second set of total capacitors 51' is 0.5pF to 3pF;

[0080] The inductance value of the series lumped inductor 52 ranges from 1nH to 5nH.

[0081] The length of the oblique metal branch 13 is 40%-60% of the length of the horizontal rectangular metal 11, and the width is 20%-40% of its width.

[0082] The thickness H3 of the air layer 8 satisfies: 0.06λ0≤H3≤0.1λ0, where λ0 is the free space wavelength of the center frequency of the antenna's operating frequency band.

[0083] The dielectric constant ε of the upper dielectric layer 2 and the lower dielectric layer 4 r The thickness is 4.4-6.0, and the thicknesses H1 and H2 are both ≤0.02λ0.

[0084] The length L of the horizontal rectangular metal 11 and the vertical rectangular metal 12 satisfy 0.6λ0≤L≤0.75λ0, and the width W satisfies 0.02λ0≤W≤0.04λ0.

[0085] The ratio of the diameter R1 of the feed metal column 6 to the width of the microstrip feed line 5 is 1:3 to 1:5, and R1 < 0.01λ0.

[0086] The antenna operates in a frequency band from 4.5 GHz to 4.9 GHz, with port isolation ≥ 20 dB and relative bandwidth ≥ 6.4%.

[0087] Example 1

[0088] Please see Figure 1 , Figure 2 and Figure 3 A high-isolation broadband four-port dual-polarized antenna based on differential and common-mode, based on the concept of common-mode and differential-mode superposition, includes a feed connector, a microstrip feed line 5, a parallel lumped element 51, a series lumped element 52, a feed metal pillar 6, a short-circuit metal pillar 7, a lower dielectric layer 4, a metal ground plane 3, an air layer 8, an upper dielectric layer 2, and a radiating patch 1. The microstrip feed line 5, the parallel lumped element 51, the series lumped element 52, the feed metal pillar 6, and the short-circuit metal pillar 7 are located on the lower surface of the lower dielectric layer 4. The feed connector is located at the edge of the lower dielectric layer 4, and there are four of them. The microstrip feed line 5 consists of four sets and is rotationally symmetrical. The two ends of the feed line are connected to the feed probe and the feed metal pillar 6, respectively. The feed metal pillar 6 passes through the lower dielectric layer 4, the air layer 8, and the upper dielectric layer 4 to excite the radiating patch 1. The parallel lumped element 51 and the series lumped element 52 are installed on the microstrip feed line 5 to achieve impedance matching and extend the operating bandwidth. The short-circuit metal post 7 is installed at the feed end of the parallel lumped element (51), passes through the lower dielectric layer 4, and connects to the metal floor 3.

[0089] Example 2

[0090] Based on the above structure, the metal floor 3 is located on the upper surface of the lower dielectric layer 4, and four circular gaps concentric with the power supply metal pillar 6 are etched on it. The diameter of the circular gaps is larger than the diameter of the power supply metal pillar 6 so as not to cause a power supply short circuit.

[0091] Example 3

[0092] Based on the above structure, the radiating patch 1 is located on the upper surface of the upper dielectric layer 1. The radiating patch 1 is composed of a horizontal rectangular metal 11, a vertical rectangular metal 12, and an oblique metal branch 13. The horizontal rectangular metal 11 and the vertical rectangular metal 12 are orthogonal, and the oblique metal branch 13 intersects with the rectangular metal 11 and the vertical rectangular metal 12 to improve the isolation between different feed ports.

[0093] Example 4

[0094] Based on the above structure, the upper dielectric layer 2 and the lower dielectric layer 4 are separated by the air layer 8. The upper dielectric layer 2 is used for printing the radiating patch 1, and the lower dielectric layer 4 is used for printing the metal floor 3 and the power supply layer.

[0095] Example 5

[0096] Based on the above structure, the high-isolation broadband four-port dual-polarized antenna based on differential common mode according to claim 1 is characterized in that the outer diameter of the lower dielectric layer 4 and the metal ground plane 3 are equal.

[0097] Example 6

[0098] Based on the above structure, the length of the horizontal rectangular metal 11 is equal to the length of the vertical rectangular metal 12, and the width of the horizontal rectangular metal 11 is equal to the width of the vertical rectangular metal 12.

[0099] Example 7

[0100] Based on the above structure, the length of the oblique metal branch 13 is less than the length of the horizontal rectangular metal 11 and the length of the vertical rectangular metal 12, and the width of the oblique metal branch 13 is less than the width of the horizontal rectangular metal 11 and the width of the vertical rectangular metal 12.

[0101] Example 8

[0102] Based on the above structure, the diameter of the power supply metal column is smaller than the width of the horizontal rectangular metal column, and also smaller than the width of the feed line.

[0103] Example 9

[0104] Based on the above structure, the diameter of the circular slit is larger than the diameter of the power-feeding metal column.

[0105] Example 10

[0106] Based on the above structure, the diameter of the short-circuit metal post is smaller than the width of the feed line.

[0107] Example 11

[0108] Based on the above structure, the outer diameters of the upper dielectric layer and the radiation patch are equal.

[0109] Test case

[0110] A high-isolation broadband four-port dual-polarized antenna based on differential and common-mode, based on the concept of common-mode and differential-mode superposition, includes a feed connector, a microstrip feed line 5, a parallel lumped element 51, a series lumped element 52, a feed metal pillar 6, a short-circuit metal pillar 7, a lower dielectric layer 4, a metal ground plane 3, an air layer 8, an upper dielectric layer 2, and a radiating patch 1. The microstrip feed line 5, the parallel lumped element 51, the series lumped element 52, the feed metal pillar 6, and the short-circuit metal pillar 7 are located on the lower surface of the lower dielectric layer 4. The feed connector is located at the edge of the lower dielectric layer 4, and there are four of them. The microstrip feed line 5 consists of four sets and is rotationally symmetrical. The two ends of the feed line are connected to the feed probe and the feed metal pillar 6, respectively. The feed metal pillar 6 passes through the lower dielectric layer 4, the air layer 8, and the upper dielectric layer 4 to excite the radiating patch 1. The parallel lumped element 51 and the series lumped element 52 are installed on the microstrip feed line 5 to achieve impedance matching and extend the operating bandwidth. The short-circuit metal post 7 is installed at the end of the feed line of the parallel lumped element (51), passing through the lower dielectric layer 4 and connecting to the metal ground plate 3. The metal ground plate 3 is located on the upper surface of the lower dielectric layer 4, and four circular slots concentric with the feed metal post 6 are etched on it. The diameter of the circular slots is larger than the diameter of the feed metal post 6 so as not to cause a feed short circuit. The radiating patch 1 is located on the upper surface of the upper dielectric layer 1. The radiating patch 1 is composed of a horizontal rectangular metal 11, a vertical rectangular metal 12, and an oblique metal branch 13. The horizontal rectangular metal 11 and the vertical rectangular metal 12 are orthogonal, and the oblique metal branch 13 intersects with the rectangular metal 11 and the vertical rectangular metal 12 to improve the isolation between different feed ports. The thickness of the lower dielectric layer is H1, the thickness of the upper dielectric layer is H2, and the two dielectric layers with a dielectric constant of εr are separated by an air layer of height H3; the outer diameter of the lower dielectric layer is L2, and the outer diameter of the upper dielectric layer is L2; ​​the length of the horizontal rectangular metal is L4, and the width is W4; the length of the horizontal rectangular metal is L5, and the width is W5; the diameter of the feed metal pillar is R1, and the diameter of the short-circuit metal pillar is R2; Medium, 0.78λ0≤L1, 0.75λ0≤L2≤0.8λ0, 0≤H1≤0.03λ0, 0≤H2≤0.03λ, 0.06λ0<H3<0.01λ0, 0.75λ0≤L4 ≤0.8λ0, 0.01λ0≤W4≤0.05λ0, 0.55λ0≤L5≤0.7λ0, 0.001λ0≤W5≤0.02λ0, R1<0.01λ0, R2<0.01λ0;

[0111] To further illustrate the beneficial effects of this invention, simulation software was used to simulate the port reflection coefficient, antenna pattern, and gain of the antennas in the above experimental examples. The simulation results are as follows: Figures 4 to 7 As shown.

[0112] Figure 4To obtain the return loss curve from the antenna simulation of the experimental example. From... Figure 4 As can be seen, the frequency range where the antenna reflection coefficient is less than -10dB is 4.54GHz-4.84GHz, the relative bandwidth is 6.4%, and the mutual coupling between different ports is less than -19.4dB.

[0113] Figure 5 The figure shows the XOZ and YOZ radiation patterns of the center frequency during the simulation of the left port of the experimental example. As can be seen from the figure, the simulated main polarization pattern achieved good cross-polarization, and the antenna obtained a radiation pattern with apical radiation.

[0114] Figure 6 The XOZ and YOZ plane radiation patterns of the center frequency during the simulation of the lower port of the experimental example are shown. As can be seen from the figure, the simulated main polarization pattern achieved good cross-polarization, and the antenna obtained a radiation pattern with apical radiation.

[0115] Figure 7 The simulated gain of the test antenna is shown in the figure. In the 4.54GHz-4.84GHz frequency band, the simulated average peak gain is greater than 4.4dBi.

[0116] In summary, the present invention provides a high-isolation broadband four-port dual-polarized antenna based on differential and common-mode, which achieves coupling suppression between the dual-polarized port and the co-polarized port by loading metal stubs; and improves the antenna impedance and achieves broadband operation by loading microstrip feed lines and lumped elements.

[0117] Although the present invention has been described in detail through the preferred embodiments above, it should be understood that the above description should not be considered as a limitation of the present invention. Various modifications and substitutions to the present invention will be apparent to those skilled in the art after reading the above description. Therefore, the scope of protection of the present invention should be defined by the appended claims.

[0118] The contents not described in detail in this specification are common knowledge to those skilled in the art.

Claims

1. A high-isolation broadband four-port dual-polarized antenna based on differential common-mode, characterized in that, It includes a feed layer, a lower dielectric layer (4), a metal floor (3), an air layer (8), an upper dielectric layer (2), and a radiating patch (1) stacked in sequence; The upper dielectric layer (2) and the lower dielectric layer (4) are separated by the air layer (8); the upper dielectric layer (2) is used to print the radiation patch (1), and the lower dielectric layer (4) is used to print the metal floor (3) and the power supply layer; The feed layer is located on the lower surface of the lower dielectric layer (4); The feed layer includes a feed connector, a microstrip feed line (5), a first lumped capacitor (51), a second lumped capacitor (51'), a lumped inductor (52), a feed metal pillar (6), and a short-circuit metal pillar (7); wherein, The power supply connector is located at the edge of the lower dielectric layer (4); The two ends of the microstrip feed line (5) are connected to the feed connector and the feed metal post (6), respectively; The feeding metal pillar (6) passes through the lower dielectric layer (4), the air layer (8) and the upper dielectric layer (2) and is connected to the radiation patch (1) to excite the radiation patch (1); The microstrip feed line (5) starts from the end of the feed metal post (6) and is connected in parallel with the first lumped capacitor (51), in series with the lumped inductor (52), and then in parallel with the second lumped capacitor (51') to achieve impedance matching and extend the operating bandwidth. The microstrip feed line (5) containing the first lumped capacitor (51) and the second lumped capacitor (51') is connected to a metal ground plane (3) by a short-circuit metal post (7) to form a short circuit.

2. The high-isolation broadband four-port dual-polarized antenna based on differential common-mode as described in claim 1, characterized in that, The metal floor (3) is located on the upper surface of the lower dielectric layer (4). Multiple circular gaps co-centered with the power supply metal pillar (6) are etched on the metal floor (3). The diameter of the circular gaps is larger than the diameter of the power supply metal pillar (6) so as not to cause a power supply short circuit.

3. The high-isolation broadband four-port dual-polarized antenna based on differential common-mode as described in claim 1, characterized in that, The radiating patch (1) is located on the upper surface of the upper dielectric layer (1). The radiating patch (1) includes a horizontal rectangular metal (11), a vertical rectangular metal (12), and an oblique metal branch (13). The horizontal rectangular metal (11) and the vertical rectangular metal (12) are orthogonal, and the oblique metal branch (13) intersects with the rectangular metal (11) and the vertical rectangular metal (12) to improve the isolation between different power supply ports.

4. The high-isolation broadband four-port dual-polarized antenna based on differential common-mode as described in claim 3, characterized in that, The length of the horizontal rectangular metal (11) is equal to the length of the vertical rectangular metal (12), and the width of the horizontal rectangular metal (11) is equal to the width of the vertical rectangular metal (12).

5. The high-isolation broadband four-port dual-polarized antenna based on differential common-mode as described in claim 1, characterized in that, The outer diameters of the lower dielectric layer (4) and the metal floor (3) are equal.

6. A high-isolation broadband four-port dual-polarized antenna based on differential common-mode as described in claim 3, characterized in that, The length of the oblique metal branch (13) is less than the length of the horizontal rectangular metal (11) and the length of the vertical rectangular metal (12), and the width of the oblique metal branch (13) is less than the width of the horizontal rectangular metal (11) and the width of the vertical rectangular metal (12).

7. A high-isolation broadband four-port dual-polarized antenna based on differential common-mode as described in claim 1, characterized in that, The diameter of the feed metal column (6) is smaller than the width of the horizontal rectangular metal (11) and also smaller than the width of the microstrip feed line (5).

8. A high-isolation broadband four-port dual-polarized antenna based on differential common-mode as described in claim 2, characterized in that, The diameter of the circular slit is greater than the diameter of the feeding metal post (6); the diameter of the short-circuit metal post (7) is less than the width of the microstrip feed line (5); the outer diameters of the upper dielectric layer (2) and the radiating patch (1) are equal.

9. The antenna according to any one of claims 1-8, characterized in that, The wiring paths of the four sets of microstrip feed lines (5) are centrally symmetrically distributed on the horizontal plane, and the main extension directions of adjacent microstrip feed lines (5) are orthogonal.

10. A wireless communication terminal, characterized in that, It integrates at least one high-isolation broadband four-port dual-polarized antenna based on differential common mode as described in any one of claims 1-9.

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