Three-frequency-band dual-polarization coaxial distribution indoor distribution antenna

Abstract

The invention discloses a three-frequency-band dual-polarization coaxially-distributed indoor distribution antenna, and relates to an antenna. Comprising a first dielectric plate, a low-frequency symmetrical dipole antenna, an intermediate-frequency directional diagram repairing strip-shaped metal structure, a high-frequency directional diagram repairing strip-shaped metal structure, an intermediate-frequency decoupling strip-shaped metal structure, a high-frequency decoupling U-shaped metal structure, a high-frequency decoupling C-shaped groove structure, a low-frequency feeder line and a low-frequency coaxial line, the antenna comprises a first dielectric plate, a second dielectric plate, an intermediate-frequency patch antenna, a repaired high-frequency directional diagram gap annular metal structure, an intermediate-frequency feed copper column, a non-metallization cube hole, a third dielectric plate, a high-frequency patch antenna, a high-frequency feeder line, a high-frequency coaxial line, a fourth dielectric plate, a metal floor, an intermediate-frequency feeder line and an intermediate-frequency coaxial line. The overall profile of the antenna is not increased, the low-frequency symmetrical oscillator antenna works normally, and distortion directional diagrams of the intermediate-frequency patch antenna and the high-frequency patch antenna are repaired. And the port isolation degrees of low-intermediate frequency, low-high frequency and medium-high frequency are all below-20dB, and the directional diagram repairing and decoupling performance is good.

Description

Technical Field

[0001] The present invention relates to the field of antenna technology, and in particular to a three-band dual-polarization coaxially distributed indoor antenna. Background Art

[0002] The traditional 0.69-0.96GHz / 1.7-2.7GHz frequency band is the 2G / 3G / 4G wireless communication frequency band, and the 3.3-3.6GHz frequency band is a frequency band for 5G base stations. Each operator has different sub-band usage intervals in these frequency bands. In future base station systems, antennas of multiple frequency bands will inevitably need to coexist due to factors such as coverage and cost, which has led to the development of various multi-frequency co-aperture antenna technologies.

[0003] In response to the above problems, the traditional solution is to arrange antennas of different frequency bands into a "one low and four high" antenna layout. However, 5G base station MIMO antennas usually require smaller array element spacing between antennas to achieve excellent scanning performance. In order to achieve a more compact layout, heterogeneous frequency antennas can be placed in a coaxial manner. When using a coaxial layout, the shielding problem of low-frequency antennas to high-frequency antennas is more serious, resulting in poor port isolation between medium- and high-frequency antennas and distorted radiation patterns. At the same time, the medium-frequency antenna also has the same shielding problem on the high-frequency antenna.

[0004] At present, some scholars have proposed using methods such as frequency selective surfaces or partial reflecting surfaces to achieve heterodyne decoupling, so as to repair the radiation pattern of the antenna located below. However, the frequency selective surface or partial reflecting surface is usually placed above the entire antenna array, which increases the cross-section of the antenna array. Summary of the invention

[0005] The purpose of the present invention is to provide a three-band dual-polarization coaxially distributed indoor antenna in view of the shortcomings of the prior art. The antenna is a low, medium and high frequency coaxial antenna. By repairing the strip metal structure of the intermediate frequency pattern, the shielding problem of the low frequency antenna on the intermediate frequency antenna is eliminated. By repairing the strip metal structure of the high frequency pattern, the shielding problem of the low frequency antenna on the high frequency antenna is eliminated. By repairing the slot ring metal structure of the high frequency pattern, the shielding problem of the intermediate frequency antenna on the high frequency antenna is eliminated. Without increasing the cross section, the distorted radiation patterns of the intermediate frequency antenna and the high frequency antenna are repaired. At the same time, the intermediate frequency decoupling strip metal structure, the high frequency decoupling U-shaped metal structure and the high frequency decoupling C-shaped slot structure are used to improve the isolation of the heterogeneous frequency antenna port. The isolation values ​​are all below -20dB, achieving a good decoupling effect. The working frequency band of the low frequency antenna is 0.69~0.96GHz, the working frequency band of the intermediate frequency antenna is 1.7~2.3GHz, and the working frequency band of the high frequency antenna is 3.3~3.6GHz.

[0006] The present invention adopts the following technical solution:

[0007] A three-band dual-polarization coaxially distributed indoor antenna comprises a first dielectric plate, a second dielectric plate, a third dielectric plate, and a fourth dielectric plate;

[0008] The upper surface of the first dielectric plate is etched with 16 strip metal structures for repairing the intermediate frequency directivity pattern, 16 strip metal structures for repairing the high frequency directivity pattern, 4 intermediate frequency decoupling strip metal structures, 4 high frequency decoupling U-shaped metal structures, and 2 low frequency feed lines;

[0009] 16 strip metal structures for repairing the IF pattern are used to repair the shielding effect of the low-frequency symmetrical dipole antenna on the IF patch antenna. Through precise electromagnetic design, the electromagnetic field distribution around the IF patch antenna is adjusted to achieve the directional radiation pattern of the IF patch antenna and ensure the efficient transmission of the IF signal in a specific direction.

[0010] 16 high-frequency pattern repair strip metal structures are used to repair the shielding effect of the low-frequency symmetrical dipole antenna on the high-frequency patch antenna, so as to realize the directional radiation pattern of the high-frequency patch antenna;

[0011] The four IF decoupling strip metal structures are used to improve the port isolation between the low-frequency symmetrical vibrator antenna and the IF patch antenna by changing the electromagnetic coupling path between the low-frequency symmetrical vibrator antenna and the IF patch antenna, thereby reducing interference between the low-frequency and IF bands.

[0012] The four high-frequency decoupling U-shaped metal structures also work together with the low-frequency symmetrical dipole antenna through a similar electromagnetic coupling control mechanism to improve the port isolation between the low-frequency symmetrical dipole antenna and the high-frequency patch antenna.

[0013] A low-frequency symmetrical dipole antenna is etched on the lower surface of the first dielectric plate, and the low-frequency symmetrical dipole antenna is composed of four ring structures; the ring structure design is conducive to the stable radiation of low-frequency signals;

[0014] The low-frequency symmetrical dipole antenna is etched with four high-frequency decoupling C-shaped groove structures to enhance the port isolation between the low-frequency symmetrical dipole antenna and the high-frequency patch antenna;

[0015] The low-frequency feed line is connected to the inner conductor of the low-frequency coaxial line to provide a stable transmission path for the input of the low-frequency signal;

[0016] An intermediate frequency patch antenna and a slot ring-shaped metal structure for repairing a high frequency pattern are etched on the upper surface of the second dielectric plate; the intermediate frequency patch antenna serves as a radiation unit for intermediate frequency signals; the slot ring-shaped metal structure for repairing a high frequency pattern is used to repair the shielding effect of the intermediate frequency patch antenna on the high frequency patch antenna, and through the slot ring-shaped design, the high frequency electromagnetic field is guided to pass through the intermediate frequency patch antenna to achieve a directional radiation pattern of the high frequency patch antenna;

[0017] The second dielectric plate is etched with non-metallized cubic holes for allowing the low-frequency coaxial line to pass through without interference, thereby ensuring that the transmission of the low-frequency feed signal is not affected by other frequency band structures;

[0018] The second dielectric plate is loaded with four intermediate frequency feeding copper pillars for exciting the intermediate frequency patch antenna;

[0019] The lower surface of the second dielectric plate has no metal structure etched thereon;

[0020] Four high-frequency feed lines are etched on the upper surface of the third dielectric plate, and the high-frequency feed lines are connected to the inner conductor of the high-frequency coaxial line to provide a channel for inputting high-frequency feed signals;

[0021] A high-frequency patch antenna is etched on the lower surface of the third dielectric plate, and the high-frequency patch antenna is connected to the outer conductor of the high-frequency coaxial line to form a complete high-frequency signal transmission path;

[0022] Two one-to-two intermediate frequency feed lines are etched on the upper surface of the fourth dielectric plate, the ends of the one-to-two intermediate frequency feed lines are connected to the intermediate frequency feeding copper column, and the front ends of the one-to-two intermediate frequency feed lines are connected to the inner conductor of the intermediate frequency coaxial line; the design of the one-to-two intermediate frequency feed line realizes the 180° phase difference branch transmission of the intermediate frequency feed signal, which plays the role of intermediate frequency antenna feeding;

[0023] A metal floor is etched on the lower surface of the fourth dielectric plate to optimize the overall electromagnetic environment of the antenna and enhance the radiation performance and directivity of the antenna.

[0024] The antenna radiation patterns of the three frequency bands of the antenna are all directional radiation radiation patterns; the directional radiation characteristics enable the antenna to concentrate energy in a specific direction, improve the efficiency and coverage of signal transmission, and meet the needs of indoor distribution systems for directional signal coverage.

[0025] The cross-sectional height of the antenna is the height of a low-frequency symmetrical dipole antenna, which achieves pattern repair and improved isolation of different-frequency ports without increasing the cross-sectional area; it not only saves antenna installation space, but also reduces installation complexity, and is particularly suitable for indoor environments with limited space.

[0026] The isolation values ​​between the different-frequency antennas of the antenna are all below -20dB, achieving a good decoupling effect; the signal interference between different frequency bands is effectively suppressed, ensuring the independent and stable transmission of signals in each frequency band, and improving the reliability and performance of the entire communication system.

[0027] In 5G communication systems, multiple-input multiple-output (MIMO) technology is crucial to improving system capacity and coverage. The three-band characteristics, good isolation and directional radiation pattern of this antenna provide strong support for the efficient and stable operation of 5G communications.

[0028] Compared with the prior art, the present invention has the following beneficial effects:

[0029] 1. Accurately repair the radiation of the IF antenna: Based on the electromagnetic principle, the strip metal structure of the IF pattern is designed to repair. When the low-frequency symmetrical vibrator antenna interferes with the IF patch antenna, these structures re-converge and guide the IF electromagnetic field through electromagnetic induction and coupling, so as to achieve accurate directional radiation of the IF patch antenna. The coverage and strength of the IF signal in complex indoor environments are greatly enhanced, providing stable and reliable communication quality for scenarios such as IoT device connection and voice communication that rely on IF signals.

[0030] 2. Efficiently optimize high-frequency antenna radiation: In response to the shielding of high frequencies by low frequencies, the high-frequency directional pattern strip metal structure is designed and repaired based on the characteristics of high-frequency electromagnetic fields. It can change the propagation trajectory of high-frequency signals and realize directional radiation of high-frequency patch antennas. At the same time, the high-frequency directional pattern gap ring metal structure designed based on the principles of electromagnetic resonance and transmission allows the high-frequency electromagnetic field to resonate at the gap, and through the shielding of the medium-frequency patch antenna, secondary focused directional radiation is achieved. The indoor coverage and quality of high-frequency signals are greatly improved to meet the high-speed communication requirements of high-bandwidth applications such as high-definition video, VR / AR, etc.

[0031] 3. Significantly improve the isolation between different frequencies: The intermediate frequency decoupling strip metal structure is reasonably arranged on the first dielectric plate to change the electromagnetic coupling path between the low frequency and the intermediate frequency, greatly reduce the interference between the frequency bands, and improve the port isolation. The high-frequency decoupling U-shaped metal structure works together with the high-frequency decoupling C-shaped slot structure, using its unique shape to change the electromagnetic field distribution between the low-frequency and high-frequency antennas to enhance the isolation effect. After testing, the isolation of the different-frequency antennas is below -20dB, ensuring that the signals of each frequency band are independently and stably transmitted, meeting the requirements of 5G indoor antennas for multiple frequency bands and high isolation.

[0032] 4. Adaptation to 5G MIMO base stations: With its three-band characteristics, good isolation and directional radiation pattern, this antenna can effectively support multiple antennas working simultaneously in the multiple-input and multiple-output scenarios of 5G communications, improve spatial multiplexing efficiency, and meet the needs of complex indoor environments for multi-band signal transmission, high spatial multiplexing and precise coverage, providing strong support for the efficient and stable operation of 5G communications.

[0033] 5. Compact structure has outstanding advantages: The antenna profile is only the height of a low-frequency symmetrical vibrator antenna, and the profile is low. This design is easy to install in office buildings, shopping malls and other scenes with limited indoor space. At the same time, the compact structure improves the overall stability of the antenna and reduces the risk of failure caused by complex structure. It reduces maintenance costs and improves the overall stability and maintainability of the system. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 It is a structural schematic diagram of a three-band dual-polarization coaxially distributed indoor antenna of the present invention.

[0035] Figure 2 Schematic diagram of the etching metal structure on the upper and lower surfaces of the first dielectric plate, wherein the left figure is the upper surface and the right figure is the lower surface.

[0036] Figure 3 Schematic diagram of the metal structure etched on the upper and lower surfaces of the second dielectric plate, wherein the left picture is the upper surface and the right picture is the lower surface.

[0037] Figure 4 Schematic diagram of the metal structure etched on the upper and lower surfaces of the third dielectric plate, wherein the left picture is the upper surface and the right picture is the lower surface.

[0038] Figure 5 Schematic diagram of the metal structure of the upper and lower surfaces of the fourth dielectric plate, wherein the left figure is the upper surface and the right figure is the lower surface.

[0039] Figure 6 The following are simulation and test results of the low-frequency antenna S parameters and gain changing with frequency. The left figure shows the low-frequency antenna S parameters, and the right figure shows the low-frequency antenna gain.

[0040] Figure 7 The following are simulation and test results of the S parameters and gain of the intermediate frequency antenna as they change with frequency. The left figure shows the S parameters of the intermediate frequency antenna, and the right figure shows the gain of the intermediate frequency antenna.

[0041] Figure 8 The figure below shows the simulation and test results of the high-frequency antenna S parameters and gain changing with frequency. The left figure shows the high-frequency antenna S parameters, and the right figure shows the high-frequency antenna gain.

[0042] Fig. 9 The following are simulation and test results of low-frequency and mid-frequency isolation changing with frequency. The left figure is low-frequency isolation, and the right figure is high-frequency isolation.

[0043] Fig.10 This is a simulation and test result diagram showing how the high-frequency band isolation varies with frequency.

[0044] Fig.11 The following are the simulation and test results of the E-plane and H-plane radiation patterns of the low-frequency antenna at 0.75 GHz. The left picture is the E-plane and the right picture is the H-plane.

[0045] Fig.12 The following are the simulation and test results of the E-plane and H-plane radiation patterns of the intermediate frequency antenna at 1.8 GHz. The left picture is the E-plane and the right picture is the H-plane.

[0046] Fig.13The following are the simulation and test results of the E-plane and H-plane radiation patterns of the high-frequency antenna at 3.35GHz. The left picture is the E-plane and the right picture is the H-plane. DETAILED DESCRIPTION

[0047] The present invention will be further described in detail below in conjunction with embodiments and drawings, but the embodiments of the present invention are not limited thereto.

[0048] like Figures 1 to 5 As shown, the embodiment of the present invention includes a first dielectric plate 1, a second dielectric plate 2, a third dielectric plate 3, and a fourth dielectric plate 4;

[0049] The upper surface of the first dielectric plate 1 is etched with 16 strip metal structures 6 for repairing the intermediate frequency directional pattern, 16 strip metal structures 7 for repairing the high frequency directional pattern, 4 intermediate frequency decoupling strip metal structures 10, 4 high frequency decoupling U-shaped metal structures 9, and 2 low frequency feed lines 11; the strip metal structure 6 for repairing the intermediate frequency directional pattern is used to repair the shielding of the low frequency antenna to the intermediate frequency antenna, so as to realize the directional radiation of the intermediate frequency patch antenna. The strip metal structure 7 for repairing the high frequency directional pattern is used to repair the shielding of the low frequency antenna to the high frequency antenna, so as to realize the directional radiation of the high frequency patch antenna. The high frequency decoupling U-shaped metal structure 9 assists in improving the port isolation between the low frequency and high frequency antennas. The intermediate frequency decoupling strip metal structure 10 is used to improve the port isolation between the low frequency and intermediate frequency antennas. The low frequency feed line 11 is connected to the inner conductor of the low frequency coaxial line 12 to provide a path for the input of the low frequency feeding signal.

[0050] A low-frequency symmetrical dipole antenna 5 is etched on the lower surface of the first dielectric plate 1. The low-frequency symmetrical dipole antenna 5 is composed of four ring structures. The low-frequency symmetrical dipole antenna 5 is etched with four high-frequency decoupling C-shaped groove structures 8 for improving the port isolation between the low-frequency antenna and the high-frequency antenna.

[0051] The upper surface of the second dielectric plate 2 is etched with an intermediate frequency patch antenna 13 and a ring-shaped metal structure 14 for repairing the high frequency pattern gap. The intermediate frequency patch antenna 13 is etched with a gap 23. The ring-shaped metal structure 14 for repairing the high frequency pattern gap is etched with a gap 24. The ring-shaped metal structure 14 for repairing the high frequency pattern gap is used to repair the shielding of the intermediate frequency antenna to the high frequency antenna.

[0052] The second dielectric plate 2 is etched with a non-metallized cube hole 18 , which provides a passage for the low-frequency coaxial line 12 to pass through; the low-frequency coaxial line 12 passes through the non-metallized cube hole 18 of the second dielectric plate 2 to transmit a low-frequency feeding signal.

[0053] The second dielectric plate 2 is etched with four metal rings 22, and the four metal rings 22 are used to load four intermediate frequency feeding copper pillars 15 respectively to excite the intermediate frequency patch antenna 13;

[0054] The lower surface of the second dielectric plate 2 has no metal structure etched thereon;

[0055] Four high-frequency feeding lines 20 are etched on the upper surface of the third dielectric plate 3 . The high-frequency feeding lines 20 are connected to the inner conductor of the high-frequency coaxial line 21 for inputting high-frequency feeding signals.

[0056] A high-frequency patch antenna 19 is etched on the lower surface of the third dielectric plate 3 , and the high-frequency patch antenna 19 is connected to the outer conductor of the high-frequency coaxial line 21 .

[0057] The third dielectric plate 3 is etched with a non-metallized circular hole 25 for passing the low-frequency coaxial line 12;

[0058] Two one-to-two intermediate frequency feed lines 16 are etched on the upper surface of the fourth dielectric plate 4. The one-to-two intermediate frequency feed line 16 is used to realize the 180° phase difference branch transmission of the intermediate frequency feed signal, and play the role of intermediate frequency antenna feeding; the end 27 of the one-to-two intermediate frequency feed line 16 is connected to the intermediate frequency feeding copper column 15, and the front end 26 of the one-to-two intermediate frequency feed line 16 is connected to the inner conductor of the intermediate frequency coaxial line 17;

[0059] The lower surface of the fourth dielectric plate 4 is etched with a metal floor;

[0060] The 16 intermediate frequency pattern repairing strip metal structures 6 are used to repair the shielding effect of the low frequency symmetrical dipole antenna 5 on the intermediate frequency patch antenna 13, so as to realize the directional radiation pattern of the intermediate frequency patch antenna 13;

[0061] The 16 high-frequency pattern repairing strip metal structures 7 are used to repair the shielding effect of the low-frequency symmetrical dipole antenna 5 on the high-frequency patch antenna 19, so as to realize the directional radiation pattern of the high-frequency patch antenna 19;

[0062] The high-frequency pattern repairing gap annular metal structure 14 is used to repair the shielding effect of the intermediate frequency patch antenna 13 on the high-frequency patch antenna 19, so as to realize the directional radiation pattern of the high-frequency patch antenna 19;

[0063] The four intermediate frequency decoupling strip metal structures 10 are used to improve the port isolation between the low frequency symmetrical dipole antenna 5 and the intermediate frequency patch antenna 13;

[0064] The four high-frequency decoupling U-shaped metal structures 9 and the four high-frequency decoupling C-shaped slot structures 8 are used to improve the port isolation between the low-frequency symmetrical dipole antenna 5 and the high-frequency patch antenna 19;

[0065] like Figure 6 As shown in the figure, the simulation and test results of the S parameters and gain of the low-frequency antenna of the embodiment of the present invention vary with frequency. The working frequency band is 0.69 to 0.96 GHz. The return loss S simulated and tested within the working bandwidth is 11 , S22 All are lower than -10dB, indicating that the antenna is well matched. The tested port isolation S 12 Lower than -24dB, indicating good port isolation, different port signals can work independently to avoid crosstalk, improve anti-interference in multi-port systems, and ensure signal purity and accuracy; the average gain of the test is 7.8dBi, indicating that the antenna gain effect is good, enhancing the coverage range and strength of low-frequency signals, which is beneficial to low-frequency signal coverage scenarios such as indoor positioning and underground parking lots. Experiments show that the low-frequency antenna of the embodiment of the present invention has excellent performance in the low-frequency band.

[0066] like Figure 7 As shown in the figure, the simulation and test results of the S parameters and gain of the intermediate frequency antenna of the embodiment of the present invention vary with frequency. The working frequency band is 1.7 to 2.3 GHz. The return loss S simulated and tested within the working bandwidth is 11 , S 22 All are lower than -10dB, indicating that the IF antenna and transmission line are well matched. The tested port isolation S 12 Lower than -28dB, indicating excellent port isolation, which can effectively avoid signal interference between different ports, ensure independent signal transmission, and improve system stability. The average gain of the test is 7.4dBi, indicating that the antenna gain is reasonable, which helps the intermediate frequency signal to achieve appropriate coverage and signal strength in the corresponding frequency band. Experiments show that the intermediate frequency antenna of the embodiment of the present invention has excellent performance in the intermediate frequency band.

[0067] like Figure 8 As shown in the figure, the simulation and test results of the S parameters and gain of the high-frequency antenna of the embodiment of the present invention vary with frequency. The working frequency band is 3.3 to 3.6 GHz. The return loss S simulated and tested within the working bandwidth is 11 , S 22 All are lower than -10dB, indicating that the high-frequency antenna and transmission line are well adapted and suitable for high-speed data transmission scenarios such as some 5G frequency bands. The tested port isolation S 12 Lower than -24dB, indicating good port isolation, which can reduce signal interference between different ports, ensure independent operation of high-frequency signals, and enhance system anti-interference. The average gain of the test is 8.9dBi; it helps to improve the coverage and strength of high-frequency signals and show advantages in high-frequency communication applications. Experiments show that the high-frequency antenna of the embodiment of the present invention shows superior performance in the 3.3-3.6GHz frequency band.

[0068] like Fig. 9 As shown in FIG. 1 , it is a simulation and test result diagram of the low-frequency band and mid-frequency band isolation varying with frequency according to an embodiment of the present invention, and the port isolation values ​​are all lower than -20dB; Fig.10 As shown in FIG. 1 , it is a simulation and test result diagram of the high frequency band isolation of the embodiment of the present invention changing with frequency, and the port isolation values ​​are all lower than -20dB; Fig. 9 and 10 It can be seen that in the antenna system of the present invention, the interference between frequency bands is effectively suppressed, the signals of different frequency bands can work independently, the isolation performance is stable, which helps to improve the performance of the multi-band communication system, ensure the stable operation of the system at different frequencies, and provide support for the system reliability in complex communication environments.

[0069] like Fig.11 As shown, the low-frequency antenna of the embodiment of the present invention is at 0.75 GHz frequency E-plane ( Fig.11 left image) and the H-plane ( Fig.11 The right figure in the figure shows the simulation and test results of the radiation pattern. The low-frequency antenna radiation pattern is a directional radiation mode, and the simulated and measured cross-polarization is less than -20dB; Fig.12 As shown, the intermediate frequency antenna of the embodiment of the present invention is at 1.8 GHz frequency E-plane ( Fig.12 left image) and the H-plane ( Fig.12 The simulation and test results of the directional pattern (right figure in the figure) show that the IF antenna directional pattern is a directional radiation mode, and the simulated and measured cross-polarization is less than -13dB; Fig.13 As shown, the high-frequency antenna of the embodiment of the present invention is at 3.35 GHz frequency E-plane ( Fig.13 left image) and the H-plane ( Fig.13 The right figure in the figure shows the simulation and test results of the radiation pattern. The high-frequency antenna radiation pattern is a directional radiation mode, and the simulated and measured cross-polarization is less than -18dB; Figures 11 to 13 It can be seen that the E-plane and H-plane radiation patterns of the low-frequency, medium-frequency and high-frequency antennas of the embodiment of the present invention are directional radiation modes at frequencies of 0.75 GHz, 1.8 GHz and 3.35 GHz, respectively, and the simulated and measured cross-polarizations of the antennas in each frequency band are less than -20 dB, -13 dB and -18 dB, respectively, indicating that the antennas in each frequency band have good directional radiation capabilities and can concentrate signals in a specific direction. At the same time, they have low cross-polarization performance, which can reduce polarization interference and ensure the signal transmission quality of communications in different frequency bands.

[0070] Experiments show that compared with other heterodyne frequency decoupling antennas using frequency selective surfaces or partially reflecting surfaces, the triple-band dual-polarization coaxial antenna of the present invention has unique advantages.

[0071] First, the cross section of the three-band dual-polarization coaxial antenna of the present invention is the height of the low-frequency symmetrical dipole antenna, and the cross section is relatively low. When the base station antenna is deployed indoors, it can better adapt to environments with limited space such as office buildings and shopping malls, reduce installation difficulty and cost, and reduce the impact on indoor structures.

[0072] Secondly, the strip metal structure for repairing the intermediate frequency directional pattern, the strip metal structure for repairing the high frequency directional pattern, and the slot ring metal structure for repairing the high frequency directional pattern used in the present invention have good directional pattern repair effects and can repair distorted directional patterns. The repair intermediate frequency structure can adjust the intermediate frequency electromagnetic field distribution through electromagnetic induction and coupling effects to repair the intermediate frequency directional pattern in response to the shielding of the low frequency to the intermediate frequency; the repair high frequency strip structure can handle the shielding of the low frequency to the high frequency, reshape the high frequency electromagnetic field to achieve normal directional radiation; and the repair high frequency slot ring structure uses electromagnetic diffraction and reflection effects to repair the shielding of the intermediate frequency to the high frequency, ensure accurate signal propagation, reduce signal blind spots, and improve the quality of communication services.

[0073] Thirdly, the port isolation of the antenna of the present invention is below -20dB in the three working frequency bands of low, medium and high frequencies (0.69-0.96GHz, 1.7-2.3GHz, 3.3-3.6GHz), achieving a good decoupling effect. Its unique structures such as the medium-frequency decoupling strip metal structure, the high-frequency decoupling U-shaped metal structure and the high-frequency decoupling C-shaped slot structure can effectively suppress interference between frequency bands and ensure independent and stable signal transmission.

[0074] Finally, the antenna demonstrates high reliability and stability in multi-band signal processing, meeting the multi-band transmission, high spatial multiplexing and precise coverage requirements of 5G MIMO antennas in complex indoor environments, promoting the deployment and application of 5G networks, and serving diversified 5G scenarios.

[0075] The above embodiments are preferred implementations of the present invention, but the implementations of the present invention are not limited to these embodiments. Any other modifications, combinations and simplifications that do not deviate from the principles and essence of the present invention are included in the protection scope of the present invention.

Claims

1. A three-band dual-polarization coaxially distributed indoor antenna, characterized in that: The invention comprises a first dielectric plate, a second dielectric plate, a third dielectric plate and a fourth dielectric plate, wherein: The upper surface of the first dielectric plate is etched with 16 strip metal structures for repairing the intermediate frequency pattern, 16 strip metal structures for repairing the high frequency pattern, 4 intermediate frequency decoupling strip metal structures, 4 high frequency decoupling U-shaped metal structures and 2 low frequency feeding lines; the 16 strip metal structures for repairing the intermediate frequency pattern are used to repair the shielding effect of the low frequency symmetrical vibrator antenna on the intermediate frequency patch antenna, so as to realize the directional radiation pattern of the intermediate frequency patch antenna; the 16 strip metal structures for repairing the high frequency pattern are used to repair the shielding effect of the low frequency symmetrical vibrator antenna on the high frequency patch antenna, so as to realize the directional radiation pattern of the high frequency patch antenna; the 4 intermediate frequency decoupling strip metal structures and the 4 high frequency decoupling U-shaped metal structures are used to improve the port isolation between the low frequency symmetrical vibrator antenna and the intermediate frequency patch antenna, and between the low frequency symmetrical vibrator antenna and the high frequency patch antenna, respectively; A low-frequency symmetrical dipole antenna is etched on the lower surface of the first dielectric plate, the low-frequency symmetrical dipole antenna is composed of four ring structures, and four high-frequency decoupling C-shaped slot structures are etched to enhance the port isolation between the low-frequency symmetrical dipole antenna and the high-frequency patch antenna; the low-frequency feed line is connected to the inner conductor of the low-frequency coaxial line to provide a stable transmission path for the input of the low-frequency signal; The upper surface of the second dielectric plate is etched with an intermediate frequency patch antenna and a ring-shaped metal structure for repairing the high frequency directional pattern gap; the ring-shaped metal structure for repairing the high frequency directional pattern gap is used to repair the shielding effect of the intermediate frequency patch antenna on the high frequency patch antenna; the second dielectric plate is also etched with a non-metallized cube hole for the low frequency coaxial line to pass through without interference, and the second dielectric plate is loaded with 4 intermediate frequency feeding copper pillars for exciting the intermediate frequency patch antenna; the lower surface of the second dielectric plate is not etched with a metal structure; Four high-frequency feed lines are etched on the upper surface of the third dielectric plate, and the high-frequency feed lines are connected to the inner conductor of the high-frequency coaxial line; a high-frequency patch antenna is etched on the lower surface of the third dielectric plate, and the high-frequency patch antenna is connected to the outer conductor of the high-frequency coaxial line, forming a complete high-frequency signal transmission and radiation loop; Two one-to-two intermediate frequency feed lines are etched on the upper surface of the fourth dielectric plate, and both ends of each one-to-two intermediate frequency feed line are respectively connected to the intermediate frequency feed copper column and the inner conductor of the intermediate frequency coaxial line; a metal floor is etched on the lower surface of the fourth dielectric plate.

2. A three-band dual-polarization coaxially distributed indoor antenna as claimed in claim 1, characterized in that: It includes three working frequency bands: the working frequency band of the low-frequency antenna is 0.69~0.96GHz, the working frequency band of the medium-frequency antenna is 1.7~2.3GHz, and the working frequency band of the high-frequency antenna is 3.3~3.6GHz. The antenna radiation patterns of the three frequency bands are all directional radiation radiation patterns.

3. The three-band dual-polarization coaxially distributed indoor antenna according to claim 1, characterized in that: The strip metal structure for repairing the intermediate frequency radiation pattern, the strip metal structure for repairing the high frequency radiation pattern, the strip metal structure for intermediate frequency decoupling, the U-shaped metal structure for high frequency decoupling and the C-shaped slot structure for high frequency decoupling are all designed through precise electromagnetic design to adjust the electromagnetic field distribution around the antennas of each frequency band to achieve a directional radiation pattern and improve port isolation.

4. The three-band dual-polarization coaxially distributed indoor antenna according to claim 1, characterized in that: The low-frequency symmetrical dipole antenna is composed of four ring structures, and the ring structure design is conducive to the stable radiation of low-frequency signals.

5. The three-band dual-polarization coaxially distributed indoor antenna according to claim 1, characterized in that: The design of the non-metallized cubic hole enables the low-frequency coaxial line to pass through the second dielectric plate without interference, ensuring that the low-frequency signal transmission is not affected by other frequency band structures.

6. The three-band dual-polarization coaxially distributed indoor antenna according to claim 1, characterized in that: The end of the one-to-two intermediate frequency feeder is connected to the intermediate frequency feed copper column, and the front end of the one-to-two intermediate frequency feeder is connected to the inner conductor of the intermediate frequency coaxial line; The design of one-to-two IF feeder line realizes the 180° phase difference branch transmission of IF signal, which plays the role of IF antenna feeding.

7. The three-band dual-polarization coaxially distributed indoor antenna according to claim 1, characterized in that: The profile height of the indoor antenna is the height of the low-frequency symmetrical dipole antenna, which can achieve pattern repair and improved isolation of different-frequency ports without increasing the profile.

8. The three-band dual-polarization coaxially distributed indoor antenna according to claim 1, characterized in that: The isolation values ​​between the different-frequency antennas of the indoor antenna are all below -20dB, achieving a good decoupling effect and effectively suppressing signal interference between different frequency bands.

9. The three-band dual-polarization coaxially distributed indoor antenna according to claim 1, characterized in that: Meet the requirements of multi-band signal transmission, high spatial multiplexing and precise coverage in 5G communication systems.

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