Broadband common-caliber base station antenna array based on composite wave-transparent structure

Abstract

The invention relates to a wide-frequency-band common-caliber base station antenna array based on a composite wave-transparent structure, and belongs to the field of base station array antennas in the mobile communication technology. Comprising a low-frequency antenna, a high-frequency antenna and a metal floor, the low-frequency antenna is located above the high-frequency antenna, and the orthographic projection of the low-frequency antenna and the orthographic projection of the high-frequency antenna are partially or completely overlapped on the metal floor; the low-frequency antenna is composed of three layers of composite wave-transparent structures, and when high-frequency electromagnetic waves irradiate the composite wave-transparent structures of the low-frequency antenna, the composite wave-transparent structures are excited to form a mixed wave-transparent structure; two or more resonance points can be introduced into the mixed wave-transparent structure, so that a broadband transmission window is further introduced, and the shielding effect on a high-frequency antenna caused by a low-frequency antenna is inhibited. The broadband common-caliber base station array antenna can work in two broadband working frequency bands, unit directional diagrams of the two frequency bands in the array are kept stable, and the broadband common-caliber base station array antenna has the advantages of being simple in structure, easy and convenient to design, capable of achieving array arrangement conveniently, low in interference and the like.

Description

Technical Field

[0001] The present invention belongs to the field of base station array antennas of mobile communication technology, and in particular relates to a wide-band common-aperture base station antenna array based on a composite wave-transmitting structure. Background Art

[0002] At present, mobile communication technology is booming, and the commercial use of 5G systems allows people to experience the convenience brought by high-speed Internet applications anytime and anywhere. However, traditional standard frequency bands still play an indispensable role, which can provide stable communication over long distances and a wide coverage range. Traditional standard systems and communication systems with high-speed transmission functions can be used in combination with complementary advantages. This requires that the current base station array needs to integrate more and more communication frequency bands. At present, the more reasonable arrangement method is to adopt a common aperture array arrangement method, which places the low-frequency antenna between the high-frequency antenna units or directly above the high-frequency antenna, which can achieve the coexistence of multiple frequency band antenna arrays without increasing the array size and profile height.

[0003] Due to the large size of the low-frequency antenna, placing the low-frequency antenna between the high-frequency antenna units or completely blocking the low-frequency antenna above the high-frequency antenna will cause a significant deterioration in the radiation pattern of the high-frequency antenna. This is an urgent problem to be solved in the co-aperture base station array. The current mainstream approach is to allow the low-frequency antenna to achieve electromagnetic transparency at high frequencies and normal radiation at low frequencies. At this time, the electromagnetic waves radiated by the high-frequency antenna will radiate outward through the electromagnetic transparent window on the low-frequency antenna, reducing the harmful induced current excited on the low-frequency antenna.

[0004] The more mature way to realize electromagnetic transparent windows is to introduce frequency selective surfaces, but single-layer slotted or striped frequency selective surfaces are greatly limited by their working bandwidth and cannot be compatible with more frequency bands and devices. Furthermore, in order to integrate with broadband devices, it is necessary to design multiple low-frequency arrays, which will increase manufacturing costs, increase array size and design difficulty.

[0005] The existing wide-band common-aperture base station array antenna has a high processing cost and difficulty to achieve high-frequency broadband transmission. It is not convenient to expand to three frequency bands, and it has a significant impact on the matching performance and radiation performance of the low-frequency antenna itself. It is necessary to design additional auxiliary structures to improve the matching performance and radiation performance of the low-frequency antenna. These effects greatly limit the application scenarios of high-frequency broadband electromagnetic transparent low-frequency arrays.

[0006] In addition, although the problem of low-frequency antenna blocking can be solved by "upper and lower arrangement" or "coaxial nesting", it will significantly increase the size of the entire array. Placing the high-frequency antenna above the low-frequency antenna by stacking can also solve the problem of pattern deterioration, but it will also increase the profile height of the array. Summary of the invention

[0007] The technical problems to be solved by the present invention are:

[0008] In order to avoid the shortcomings of the prior art, the present invention provides a wide-band common-aperture base station antenna array based on a composite wave-transmitting structure, which is used to solve the problems of high processing cost and difficulty in processing of existing wide-band common-aperture base station antenna arrays, and deteriorated matching and radiation performance of high-frequency broadband wave-transmitting antennas, eliminate the shielding problem between internal antennas, and realize the normal radiation of the broadband high-frequency working unit directional pattern in the array.

[0009] In order to solve the above technical problems, the technical solution adopted by the present invention is:

[0010] A wide-band co-aperture base station antenna array based on a composite wave-transmitting structure, characterized in that it includes a low-frequency antenna, a high-frequency antenna and a metal floor, wherein the low-frequency antenna is located above the high-frequency antenna, and the orthographic projection of the low-frequency antenna and the orthographic projection of the high-frequency antenna partially or completely overlap on the metal floor;

[0011] The low-frequency antenna is composed of a three-layer composite wave-transmitting structure. When the high-frequency electromagnetic wave irradiates the composite wave-transmitting structure of the low-frequency antenna, the composite wave-transmitting structure is excited to form a hybrid wave-transmitting structure. The hybrid wave-transmitting structure can introduce two or more resonance points, and then introduce a broadband transmission window, thereby suppressing the shielding effect of the low-frequency antenna on the high-frequency antenna.

[0012] A further technical solution of the present invention: the low-frequency antenna comprises, from top to bottom, a first electromagnetic surface, a second electromagnetic surface, and a third electromagnetic surface, the first electromagnetic surface, the second electromagnetic surface, and the third electromagnetic surface are separated by air layers with the same intervals; wherein the second electromagnetic surface is the radiation structure of the low-frequency antenna.

[0013] A further technical solution of the present invention is as follows: the first electromagnetic surface includes a first dielectric substrate and a first metal square ring printed on the lower surface of the first dielectric substrate, wherein the first metal square rings are arranged in an array to form a first array.

[0014] A further technical solution of the present invention: the second electromagnetic surface includes a second dielectric substrate and a composite metal structure printed on the lower surface of the second dielectric substrate, wherein the composite metal structure is arranged in an array to form a second array, and two diagonally opposite second arrays respectively constitute a first square ring radiation group and a second square ring radiation group to achieve a ±45° polarized radiation function.

[0015] A further technical solution of the present invention is as follows: the composite metal structure comprises a square metal frame and a Jerusalem zigzag strip, wherein the Jerusalem zigzag strip is located within the square metal frame, and the two Jerusalem zigzag strips are distributed in a cross form.

[0016] A further technical solution of the present invention is as follows: a first forked coupling metal strip and a second forked coupling metal strip are printed in the middle of the upper surface of the second dielectric substrate, and the first forked coupling metal strip transfers the energy in the first coaxial line to the low-frequency first square ring radiation group by coupling; the second forked coupling metal strip transfers the energy in the second coaxial line to the second square ring radiation group by coupling; one end of the first coaxial line is connected to the coupling metal strip of the first forked coupling metal strip, and one end of the second coaxial line is connected to the second forked coupling metal strip; the other end of the first coaxial line and the other end of the second coaxial line are respectively connected to the feeding end through the metal floor.

[0017] A further technical solution of the present invention is as follows: the third electromagnetic surface includes a first dielectric substrate and a second metal square ring printed on the lower surface of the third dielectric substrate, wherein the second metal square rings are arranged in an array to form a third array.

[0018] A further technical solution of the present invention is as follows: the high-frequency antenna is single or multiple. When it is a single high-frequency antenna, it can be completely placed directly below the low-frequency antenna, and the orthographic projection of the low-frequency antenna and the orthographic projection of the high-frequency antenna completely overlap on the metal floor; when it is an array composed of multiple high-frequency antennas, the low-frequency antenna and the high-frequency antenna are arranged in an alternating manner, and the orthographic projection of the low-frequency antenna and the orthographic projection of the high-frequency antenna partially overlap on the metal floor.

[0019] A further technical solution of the present invention: the high-frequency antenna includes a fourth dielectric substrate and a fifth dielectric substrate, and the fifth dielectric substrate is located above the fourth dielectric substrate; wherein a rectangular radiation patch is printed on the lower surface of the fourth dielectric substrate, and a rectangular parasitic patch is printed on the lower surface of the fifth dielectric substrate.

[0020] A further technical solution of the present invention: the high-frequency antenna also includes a first feeding group and a second feeding group printed on the upper surface of a fourth dielectric substrate, and both feeding structures feed the rectangular radiation patch by differential feeding to achieve a dual-polarization radiation effect; wherein the first feeding group and the fourth feeding group each include two identical bent feeding structures, and the first bent feeding line and the second bent feeding line included in the first feeding group transfer the energy in the third coaxial line and the fourth coaxial line to the rectangular radiation patch in the form of coupling, and the amplitudes of the feeding excitations in the third coaxial line and the fourth coaxial line are the same, and the phases are opposite; the third bent feeding line and the fourth bent feeding line included in the second feeding group transfer the energy in the fifth coaxial line and the sixth coaxial line to the rectangular radiation patch in the form of coupling, and the amplitudes of the feeding excitations in the fifth coaxial line and the sixth coaxial line are the same, and the phases are opposite.

[0021] The beneficial effects of the present invention are:

[0022] The invention provides a wide-band common-aperture base station antenna array based on a composite wave-transparent structure, which uses a low-frequency antenna with broadband high-frequency electromagnetic transparency to be compatible with systems in more frequency bands, saving the design complexity and processing costs of multiple low-frequency antennas, while improving compatibility without increasing the array height or lateral dimensions, and can be applied in a variety of scenarios. Compared with the prior art, it has the following advantages:

[0023] 1. The present invention converts the radiation structure of the low-frequency antenna into a composite broadband electromagnetic transparent surface, introduces two or more transmission resonance points in its working frequency band, expands the wave transmission bandwidth, can reduce the shielding effect within the wide-band range, and achieve normal radiation of the broadband high-frequency antenna. The broadband wave-transmitting structure is simple in design, easy to design, and convenient to optimize. At the same time, the broadband compatibility effect with the high-frequency antenna is achieved without almost increasing the overall array profile height. It also avoids the introduction of high-dielectric-constant dielectric plates and complex engineering structures to achieve broadband transmission effects, reducing the array processing cost and difficulty.

[0024] 2. The present invention achieves high-frequency broadband transmission effect by directly improving the low-frequency array, without increasing the array spacing and stacking the array to reduce the shielding effect of the low-frequency antenna; it saves the array size and does not increase the array height; at the same time, it avoids the design of an isolation surface used in the stacked arrangement between the low-frequency and high-frequency antennas to achieve low-frequency reflection and broadband high-frequency transmission, further reducing the design complexity and array processing costs.

[0025] 3. The improvement of the low-frequency antenna radiation structure and the introduction of the multi-layer electromagnetic surface above and below the low-frequency radiation structure in the present invention have almost no effect on the radiation performance and matching performance of the low-frequency antenna, avoiding the processing of the corresponding matching network and components, and there is no need to make additional improvements to the antenna feeding structure.

[0026] 4. The improvement of the low-frequency antenna and the introduction of additional electromagnetic surfaces in the present invention can realize the expansion to a dual-band broadband common-aperture base station array antenna. The multi-layer composite electromagnetic transmission surface expands the design freedom of the traditional frequency selective surface, and can introduce multiple transmission poles in both transmission frequency bands, which has the ability to expand to a dual-band broadband common-aperture base station array and even a triple-band common-aperture broadband base station array.

[0027] In summary, the present invention has the advantages of simple structure, wide working bandwidth, stable radiation pattern, and convenient array deployment. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The drawings are only for the purpose of illustrating particular embodiments and are not to be considered limiting of the present invention. Like reference symbols denote like components throughout the drawings.

[0029] Figure 1This is the overall structural diagram of the broadband common-aperture base station antenna array based on the composite wave-transmitting structure of the present invention;

[0030] Figure 2 It is a top view of a broadband common-aperture base station antenna array based on a composite wave-transmitting structure of the present invention;

[0031] Figure 3 This is the overall structural diagram of the high-frequency, broadband, wave-transmitting low-frequency antenna based on the composite wave-transmitting structure of the present invention;

[0032] Figure 4 (a) is a diagram showing the printed metal structure of the first dielectric substrate of the high-frequency, broadband, wave-transmitting low-frequency antenna based on a composite wave-transmitting structure of the present invention;

[0033] Figure 4 (b) is a diagram showing the printed metal structure of the second dielectric substrate of the high-frequency, broadband, wave-transmitting low-frequency antenna based on a composite wave-transmitting structure of the present invention;

[0034] Figure 4 (c) is a diagram of the printed metal structure of the third dielectric substrate of the high-frequency, broadband, wave-transmitting low-frequency antenna based on the composite wave-transmitting structure of the present invention;

[0035] Figure 5 This is a diagram of the feeding structure of a high-frequency, broadband, wave-transmitting low-frequency antenna based on a composite wave-transmitting structure of the present invention;

[0036] Figure 6 (a) is the overall structure diagram of the high frequency antenna of the present invention;

[0037] Figure 6 (b) is a feeding structure diagram of the high frequency antenna of the present invention;

[0038] Figure 7 It is a port marking diagram of the broadband common aperture base station antenna of the present invention;

[0039] Figure 8 (a) is the present invention at 1.7 GHz, azimuth When the elevation angle θ is 90° and the pitch angle θ is –180° to 180°, the directivity patterns of the proposed array, the traditional array, and the single high-frequency unit are compared when ports Port3 and Port4 are differentially fed;

[0040] Figure 8 (b) is the present invention at 1.9 GHz, azimuth When the elevation angle θ is 90° and the pitch angle θ is –180° to 180°, the directivity patterns of the proposed array, the traditional array, and the single high-frequency unit are compared when ports Port3 and Port4 are differentially fed;

[0041] Figure 8 (c) is the present invention at 2.1 GHz and azimuth When the elevation angle θ is 90° and the pitch angle θ is –180° to 180°, the directivity patterns of the proposed array, the traditional array, and the single high-frequency unit are compared when ports Port3 and Port4 are differentially fed;

[0042] Figure 8 (d) is the present invention at 2.3 GHz, azimuth When the elevation angle θ is 90° and the pitch angle θ is –180° to 180°, the directivity patterns of the proposed array, the traditional array, and the high-frequency array alone are compared when ports Port3 and Port4 are differentially fed;

[0043] Figure 8 (e) is the present invention at 2.5 GHz and azimuth When the elevation angle θ is 90° and the pitch angle θ is –180° to 180°, the directivity patterns of the proposed array, the traditional array, and the high-frequency array alone are compared when ports Port3 and Port4 are differentially fed;

[0044] Figure 8 (f) is a comparison of the directional patterns of the present invention in the proposed array, the traditional array, and the single high-frequency array when ports Port3 and Port4 are differentially fed at 2.7 GHz, azimuth angles φ = 0° and 90°, and elevation angles θ = -180° to 180°;

[0045] Fig. 9 A schematic diagram of the overall structure of Embodiment 2 of the present invention;

[0046] Fig.10 (a) is a schematic diagram of the shielding effect of a traditional co-aperture base station array antenna;

[0047] Fig.10 (b) is a schematic diagram of the operation of the broadband common-aperture base station array antenna based on the composite wave-transmitting structure of the present invention;

[0048] Fig.11 It is the S parameter of the broadband composite electromagnetic transparent structure of the present invention.

[0049] In the figure: 1- low frequency antenna; 2- first electromagnetic surface; 3- second electromagnetic surface; 4- third electromagnetic surface; 5- high frequency antenna; 6- metal floor; 7- first support column; 8- first forked coupling metal strip; 9- second forked coupling metal adjustment; 10- first coaxial line; 11- second coaxial line; 12- second support column; 21- first metal square ring; 22- first array; 23- first dielectric substrate; 31- composite metal structure; 32- square metal frame; 33- Jerusalem zigzag metal strip; 34- second dielectric substrate; 35- second array; 36- first square ring radiation group; 37- second square ring radiation group; 41- second metal square ring; 42- first Three arrays; 43-third dielectric substrate; 51-rectangular radiation patch; 52-rectangular parasitic patch; 53-fourth dielectric substrate; 54-fifth dielectric substrate; 55-first rectangular gap; 56-first feeding group; 57-second feeding group; 58-first feeding coaxial line group; 59-second feeding coaxial line group; 521-first triangular cut corner; 522-second rectangular gap; 561-first bent feeding line; 562-second bent feeding line; 563-second triangular cut corner; 571-third bent feeding line; 572-fourth bent feeding line; 581-third coaxial line; 582-fourth coaxial line; 591-fifth coaxial line; 592-sixth coaxial line. DETAILED DESCRIPTION

[0050] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0051] It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the terms used in this way can be interchangeable where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0052] In the description of the present invention, it is necessary to understand that the terms "upper", "lower", "front", "back", "left", "right", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship are based on the orientation or position relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0053] The present invention provides a wide-band common-aperture base station antenna array based on a composite wave-transparent structure. The radiation structure of the antenna is improved without affecting the radiation performance of the low-frequency antenna. A composite electromagnetic transparent resonant structure is formed by combining multiple layers of electromagnetic surfaces introduced above and below the antenna, and two or more resonance points can be introduced, thereby greatly widening the electromagnetic transparent bandwidth at high frequencies.

[0054] By directly converting the low-frequency antenna radiation structure into a composite surface with broadband electromagnetic transparency, a broadband reduction effect on the shielding effect of the high-frequency antenna is achieved without almost increasing the array profile height. It avoids reducing the shielding of the high-frequency antenna by the low-frequency antenna by increasing the array size and placing the high-frequency array above the low-frequency antenna in a stacked manner. Furthermore, the low-frequency antenna with high-frequency broadband electromagnetic transparency reduces the design complexity of introducing multiple low-frequency arrays for compatibility with multi-frequency systems. The electromagnetic surface introduced above and below the low-frequency radiation structure has almost no effect on the radiation effect of the low-frequency antenna, avoiding the application restrictions caused by the reduction of the radiation performance of the low-frequency antenna itself. The array has the characteristics of simple structure, easy design, stable radiation pattern, and broadband compatibility.

[0055] The present invention provides a wide-band co-aperture base station antenna array based on a composite wave-transmitting structure, comprising a low-frequency antenna, a high-frequency antenna and a metal floor, wherein the low-frequency antenna is located above the high-frequency antenna, and the orthographic projection of the low-frequency antenna and the orthographic projection of the high-frequency antenna partially or completely overlap on the metal floor;

[0056] The low-frequency antenna is composed of a three-layer composite wave-transmitting structure. When the high-frequency electromagnetic wave irradiates the composite wave-transmitting structure of the low-frequency antenna, the composite wave-transmitting structure is excited to form a hybrid wave-transmitting structure. The hybrid wave-transmitting structure can introduce two or more resonance points, and then introduce a broadband transmission window, thereby suppressing the shielding effect of the low-frequency antenna on the high-frequency antenna.

[0057] The high-frequency antenna is single or multiple. When it is a single high-frequency antenna, it can be completely placed directly under the low-frequency antenna. It is a stacked arrangement, and the orthographic projection of the low-frequency antenna and the orthographic projection of the high-frequency antenna completely overlap on the metal floor; when it is an array composed of multiple high-frequency antennas, the low-frequency antenna and the high-frequency antenna are arranged in an alternating manner, and the orthographic projection of the low-frequency antenna and the orthographic projection of the high-frequency antenna partially overlap on the metal floor.

[0058] Embodiment 1:

[0059] like Figure 1 The embodiment of the present invention provides a broadband common aperture base station array antenna based on a composite wave-transmitting structure, specifically a dual-frequency dual-polarization broadband common aperture base station array antenna, including a metal floor 6, a low-frequency antenna 1 arranged in the middle of the upper surface of the metal floor 6, the low-frequency antenna 1 is composed of three layers of composite wave-transmitting structure, and a 4×4 array composed of high-frequency antennas 5 is symmetrically arranged below the low-frequency antenna 1. Figure 2 As shown, the low-frequency antenna 1 is located at the top of the entire array; and the high-frequency antenna 5 is located at the bottom of the entire array.

[0060] The low frequency antenna 1 operates at 0.69-0.96 GHz, and the high frequency antenna operates at 1.7-2.7 GHz.

[0061] like Figure 3 As shown, the low-frequency antenna 1 includes, from top to bottom, a first electromagnetic surface 2, a second electromagnetic surface 3, and a third electromagnetic surface 4, and the first electromagnetic surface 2, the second electromagnetic surface 3, and the third electromagnetic surface 4 are separated by air layers with the same interval; wherein the second electromagnetic surface 3 acts as a radiation structure, and the feeding structure directly feeds the second electromagnetic surface 3; the first electromagnetic surface 2, the second electromagnetic surface 3, and the third electromagnetic surface 4 are all fixed on the metal floor 6 through a first support column 7.

[0062] Preferably, the dielectric substrates of the first electromagnetic surface 2 , the second electromagnetic surface 3 , and the third electromagnetic surface 4 have a dielectric constant of 3, an electrical loss of 0.0013, and a thickness of 1 mm.

[0063] like Figure 4 As shown in (a), the first electromagnetic surface 2 includes a first dielectric substrate 23, a first metal square ring 21 printed on the lower surface of the first dielectric substrate 23, the first metal square ring 21 is arranged in a 3×3 manner at the upper left corner of the dielectric substrate 23 to form a first array 22, and the first array 22 is arranged in a 2×2 manner to form a metal structure on the lower surface of the first dielectric substrate 23.

[0064] like Figure 4 As shown in (b), the second electromagnetic surface 3 includes a second dielectric substrate 34, a composite metal structure 31 printed on the lower surface of the second dielectric substrate 34, and the composite metal structure 31 includes an external square metal frame 32 and an internal Jerusalem zigzag strip 33; the composite metal structure 31 is arranged in a 3×3 manner to form a second array 35, and the second array 35 is arranged in a 2×2 manner to form a metal structure on the lower surface of the second dielectric substrate 34. Further, the second array 35 is divided into a low-frequency first square ring radiation group 36 and a low-frequency second square ring radiation group 37 that are diagonally opposite to each other to achieve a ±45° polarized radiation function.

[0065] like Figure 4 As shown in (c), the third electromagnetic surface 4 has the same structure as the first electromagnetic surface 2, including a third dielectric substrate 43, a second metal square ring 41 printed on the lower surface of the third dielectric substrate 43, the second metal square ring 41 is arranged in a 3×3 manner at the upper left corner of the dielectric substrate 43 to form a third array 42, and the third array 42 is arranged in a 2×2 manner to form a metal structure on the lower surface of the third dielectric substrate 43.

[0066] When the above three-layer composite wave-transmitting structure resonates, a second-order broadband equivalent circuit is formed, which can generate two transmission poles and greatly expand the wave-transmitting bandwidth.

[0067] like Figure 5 As shown, a first forked coupling metal strip 8 and a second forked coupling metal strip 9 are printed in the middle of the front side of the second dielectric substrate 34, and the first forked coupling metal strip 8 transfers the energy in the first coaxial line 10 to the low-frequency first square ring radiation group 36 by coupling; the second forked coupling metal strip 9 transfers the energy in the second coaxial line 11 to the low-frequency second square ring radiation group 37 by coupling; one end of the first coaxial line 10 is connected to the coupling metal strip of the first forked coupling metal strip 8, and one end of the second coaxial line 11 is connected to the coupling metal strip of the second coaxial line 11. The two forked coupling metal strips 9 are connected; the other end of the first coaxial line 10 and the other end of the second coaxial line 11 pass through the metal floor 6 respectively; the first forked coupling metal strip 8 is not connected to the first square ring radiation group 36, and the second forked coupling metal strip 9 is not connected to the second radiation square ring group 37; the two groups of forked coupling metal strips directly feed the first square ring radiation group 36 and the second square ring radiation group 37 on the lower surface of the second dielectric substrate 34; the metal structure printed on the lower surface of the first dielectric substrate 23 and the third dielectric substrate 43 has almost no effect on the radiation.

[0068] like Figure 7 As shown, the high frequency antenna 5 of the embodiment of the present invention is arranged in a 2×2 manner around the low frequency antenna 1.

[0069] like Figure 6 As shown in (a), the high-frequency antenna 5 includes a fourth dielectric substrate 53 and a fifth dielectric substrate 54, and the fifth dielectric substrate 54 is located above the fourth dielectric substrate 51; the fourth dielectric substrate 53 and the fifth dielectric substrate 54 are both fixed above the floor 6 through the second support column 12.

[0070] A rectangular radiation patch 51 is printed on the lower surface of the fourth dielectric substrate 53, and the four vertices of the rectangular radiation patch 51 have second triangular cut corners 563, and a first rectangular slit 55 is provided in the middle of each side of the rectangular radiation patch 51. A rectangular parasitic patch 52 is printed on the lower surface of the fifth dielectric substrate 54, and the four vertices of the rectangular parasitic patch have first triangular cut corners 521, and the four sides thereof have second rectangular slits 522.

[0071] like Figure 6 As shown in (b), the high-frequency antenna 5 also includes a first feeding group 56 and a second feeding group 57 printed on the upper surface of the fourth dielectric substrate 54. Both feeding structures feed the rectangular radiation patch 51 by differential feeding to achieve a dual-polarization radiation effect; the first feeding group 56 includes two identical first meandering feeding lines 561 and second meandering feeding lines 562; the second feeding group 57 is constructed exactly the same as the first feeding group 56, including two identical third meandering feeding lines 571 and fourth meandering feeding lines 572; the first feeding group 56 cooperates with the first feeding coaxial line group 58, and the second feeding group 57 cooperates with the second feeding coaxial line group 59; wherein, the first feeding coaxial line group 58 includes a third coaxial line 581 and a fourth coaxial line 582, and the second feeding coaxial line group 59 includes a fifth coaxial line 591 and a sixth coaxial line 592. The first meander feed line 561 and the second meander feed line 562 transfer the energy in the third coaxial line 581 and the fourth coaxial line 582 to the rectangular radiation patch 51 by coupling, wherein the amplitude of the feeding excitation in the third coaxial line 584 and the fourth coaxial line 582 is the same and the phase is opposite; the third meander feed line 571 and the fourth meander feed line 572 transfer the energy in the fifth coaxial line 591 and the sixth coaxial line 592 to the rectangular radiation patch 51 by coupling, wherein the amplitude of the feeding excitation in the fifth coaxial line 591 and the sixth coaxial line 592 is the same and the phase is opposite.

[0072] Preferably, the fourth dielectric substrate 53 and the fifth dielectric substrate 54 have a dielectric constant of 4.4, an electrical loss of 0.02, and a thickness of 0.8 mm.

[0073] Embodiment 2:

[0074] This embodiment provides a broadband common aperture base station array antenna based on a composite wave-transmitting structure, such as Fig. 9 As shown, it is specifically a dual-frequency dual-polarization broadband co-aperture base station array antenna. In this embodiment, it includes one high-frequency antenna, and the low-frequency antenna is completely placed above the high-frequency antenna, and the high-frequency antenna and the low-frequency antenna are stacked. The low-frequency antenna and the broadband high-frequency antenna based on the composite wave-transparent structure in the array are exactly the same as those in Example 1, and its feeding structure passes through the middle of the high-frequency antenna, which does not affect any radiation performance of the high-frequency antenna.

[0075] The dual-band common-aperture base station array antenna proposed in the present invention does not carry any circuit elements, and the additional isolation surface is only composed of a dielectric substrate and metal etched thereon, so that stable operation with a wide-band directional pattern can be achieved.

[0076] The present invention avoids the use of dielectric plates with high dielectric constants, complex 3D resonant structures, enlarged array spacing and stacked arrangements, and realizes the design of broadband common-aperture base station array antennas without increasing processing costs, difficulty, array size and cross-section. The directional patterns in the high-frequency broadband range are stably radiated, and the matching of low-frequency and high-frequency antennas is good.

[0077] The effect of the present invention can be further illustrated by the following simulation:

[0078] 1. Simulation software:

[0079] Commercial Ansoft HFSS19.2 software.

[0080] 2. Simulation content:

[0081] Simulation 1:

[0082] like Figure 8 (a) As mentioned above, when the azimuth When the elevation angle θ is 0° to 360°, the high frequency antenna of the present invention is Figure 7 The ports numbered as Port 3 and Port 4 are excited by differential feeding under different conditions, including 1. the directional pattern of the high-frequency antenna array under the broadband high-frequency electromagnetic transparent low-frequency antenna based on the composite wave-transmitting structure proposed in the present invention, 2. the directional pattern of the high-frequency unit under the traditional low-frequency unit, in which the radiation structure of the low-frequency antenna is not improved in any way, it is a rectangular patch, and no additional electromagnetic surface is introduced, 3. the directional pattern when there is only a high-frequency unit. Among them, the size of the traditional low-frequency antenna is consistent with the size of the low-frequency antenna in the present invention.

[0083] Depend on Figure 8 (a) It can be seen that the radiation pattern of the high-frequency unit under the traditional low-frequency unit is distorted in the axial direction, the gain is reduced, and the beam width is narrowed in the range of 0-30°; while the radiation pattern of the high-frequency unit when the low-frequency antenna is improved to a composite structure that produces broadband electromagnetic transparency at high frequencies is almost consistent with the radiation pattern when there is only a high-frequency unit, and no obvious distortion occurs.

[0084] Simulation 2:

[0085] like Figure 8 (b) As mentioned above, when the azimuth When the elevation angle θ is 0° to 360°, the high frequency antenna of the present invention is Figure 7The ports numbered as Port 3 and Port 4 are excited by differential feeding under different conditions, including 1. the directional pattern of the high-frequency antenna array under the broadband high-frequency electromagnetic transparent low-frequency antenna based on the composite wave-transmitting structure proposed in the present invention, 2. the directional pattern of the high-frequency unit under the traditional low-frequency unit, in which the radiation structure of the low-frequency antenna is not improved in any way, it is a rectangular patch, and no additional electromagnetic surface is introduced, 3. the directional pattern when there is only a high-frequency unit. Among them, the size of the traditional low-frequency antenna is consistent with the size of the low-frequency antenna in the present invention.

[0086] Depend on Figure 8 (b) It can be seen that the radiation pattern of the high-frequency unit under the traditional low-frequency unit is distorted in the axial direction. Within the range of ±30°, the gain and beamwidth are deteriorated. However, when the low-frequency antenna is improved to a composite structure that produces broadband electromagnetic transparency at high frequencies, the radiation pattern of the high-frequency unit is almost consistent with the radiation pattern when there is only a high-frequency unit, and no obvious distortion occurs.

[0087] Simulation 3:

[0088] like Figure 8 (c) As mentioned above, when the azimuth When the elevation angle θ is 0° to 360°, the high frequency antenna of the present invention is Figure 7 The ports numbered as Port 3 and Port 4 are excited by differential feeding under different conditions, including 1. the directional pattern of the high-frequency antenna array under the broadband high-frequency electromagnetic transparent low-frequency antenna based on the composite wave-transmitting structure proposed in the present invention, 2. the directional pattern of the high-frequency unit under the traditional low-frequency unit, in which the radiation structure of the low-frequency antenna is not improved in any way, it is a rectangular patch, and no additional electromagnetic surface is introduced, 3. the directional pattern when there is only a high-frequency unit. Among them, the size of the traditional low-frequency antenna is consistent with the size of the low-frequency antenna in the present invention.

[0089] Depend on Figure 8 (c) It can be seen that the radiation pattern of the high-frequency unit under the traditional low-frequency unit has obvious distortion in the axial direction, and the gain is significantly reduced by more than 3dBi; while the radiation pattern of the high-frequency unit when the low-frequency antenna is improved to produce a composite structure with broadband electromagnetic transparency at high frequencies is almost consistent with the radiation pattern when there is only a high-frequency unit, and no obvious distortion occurs.

[0090] Simulation 4:

[0091] like Figure 8 (d) As mentioned above, when the azimuth When the elevation angle θ is 0° to 360°, the high frequency antenna of the present invention is Figure 7The ports numbered as Port 3 and Port 4 are excited by differential feeding under different conditions, including 1. the directional pattern of the high-frequency antenna array under the broadband high-frequency electromagnetic transparent low-frequency antenna based on the composite wave-transmitting structure proposed in the present invention, 2. the directional pattern of the high-frequency unit under the traditional low-frequency unit, in which the radiation structure of the low-frequency antenna is not improved in any way, it is a rectangular patch, and no additional electromagnetic surface is introduced, 3. the directional pattern when there is only a high-frequency unit. Among them, the size of the traditional low-frequency antenna is consistent with the size of the low-frequency antenna in the present invention.

[0092] Depend on Figure 8 (d) It can be seen that the radiation pattern of the high-frequency unit under the traditional low-frequency unit is severely suppressed in the axial direction, the radiation pattern is seriously deteriorated, and the gain is reduced, decreasing by more than 5dBi; while the radiation pattern of the high-frequency unit when the low-frequency antenna is improved to a composite structure that produces broadband electromagnetic transparency at high frequencies is almost consistent with the radiation pattern when there is only a high-frequency unit, and no obvious distortion occurs.

[0093] Simulation 5:

[0094] like Figure 8 (e) As mentioned above, when the azimuth When the elevation angle θ is 0° to 360°, the high frequency antenna of the present invention is Figure 7 The ports numbered as Port 3 and Port 4 are excited by differential feeding under different conditions, including 1. the directional pattern of the high-frequency antenna array under the broadband high-frequency electromagnetic transparent low-frequency antenna based on the composite wave-transmitting structure proposed in the present invention, 2. the directional pattern of the high-frequency unit under the traditional low-frequency unit, in which the radiation structure of the low-frequency antenna is not improved in any way, it is a rectangular patch, and no additional electromagnetic surface is introduced, 3. the directional pattern when there is only a high-frequency unit. Among them, the size of the traditional low-frequency antenna is consistent with the size of the low-frequency antenna in the present invention.

[0095] Depend on Figure 8 (e) It can be seen that the radiation pattern of the high-frequency unit under the traditional low-frequency unit has obvious distortion in the axial direction, and the radiation pattern is seriously deteriorated in the range of ±30°. Although the axial gain is reduced less, the beam width decreases significantly. When the low-frequency antenna is improved to a composite structure that produces broadband electromagnetic transparency at high frequencies, the radiation pattern of the high-frequency unit is almost consistent with the radiation pattern when there is only a high-frequency unit, and no obvious distortion occurs.

[0096] Simulation 6:

[0097] like Figure 8 (f) As mentioned above, when the azimuth When the elevation angle θ is 0° to 360°, the high frequency antenna of the present invention is Figure 7The ports numbered as Port 3 and Port 4 are excited by differential feeding under different conditions, including 1. the directional pattern of the high-frequency antenna array under the broadband high-frequency electromagnetic transparent low-frequency antenna based on the composite wave-transmitting structure proposed in the present invention, 2. the directional pattern of the high-frequency unit under the traditional low-frequency unit, in which the radiation structure of the low-frequency antenna is not improved in any way, it is a rectangular patch, and no additional electromagnetic surface is introduced, 3. the directional pattern when there is only a high-frequency unit. Among them, the size of the traditional low-frequency antenna is consistent with the size of the low-frequency antenna in the present invention.

[0098] Depend on Figure 8 (f) It can be seen that the radiation pattern of the high-frequency unit under the traditional low-frequency unit has obvious distortion in the axial direction, and the axial gain is reduced by more than 3dBi; while the radiation pattern of the high-frequency unit when the low-frequency antenna is improved to a composite structure that produces broadband electromagnetic transparency at high frequencies is almost consistent with the radiation pattern when there is only a high-frequency unit, and no obvious distortion occurs.

[0099] Fig.10 (a) is a schematic diagram of the shielding effect of a traditional co-aperture base station array antenna. If the overall array profile height is not increased, the antennas of each frequency band will be placed on a common reflective floor. Therefore, the low-frequency antenna will produce secondary radiation under the excitation of the surrounding broadband high-frequency antennas, resulting in a more serious shielding effect.

[0100] Fig.10 (b) is a schematic diagram of the operation of the broadband common-aperture base station array antenna based on the composite wave-transparent structure of the present invention. The multi-layer composite electromagnetic transparent structure is introduced into the design of the low-frequency antenna to form a broadband transparent electromagnetic window for the high-frequency antenna, thereby reducing the shielding effect and realizing the normal radiation of the high-frequency antenna.

[0101] Fig.11 is the S parameter of the broadband composite electromagnetic transparent structure of the present invention. Within 1.7-2.7 GHz, the transmission coefficient is greater than -0.9 dB, achieving a good wave transmission effect and reducing the shielding effect of the low-frequency antenna radiation patch.

[0102] The above descriptions are only two embodiments of the present invention and do not constitute any limitation to the present invention. It should be understood that the present invention is not limited to the forms disclosed herein and should not be regarded as excluding other embodiments, including the specific features, structures, materials or characteristics described in the present invention can be combined and modified in any one or more embodiments in a suitable manner. Obviously, for professionals in this field, after understanding the content and principles of the present invention, it is possible to make various modifications and changes in form and details without departing from the principles and structures of the present invention, but these modifications and changes based on the ideas of the present invention are still within the claims and protection scope of the present invention.

Claims

1. A wide-band common-aperture base station antenna array based on a composite wave-transmitting structure, characterized in that: The device comprises a low-frequency antenna (1), a high-frequency antenna (5) and a metal floor (6), wherein the low-frequency antenna (1) is located above the high-frequency antenna, and the orthographic projection of the low-frequency antenna (1) and the orthographic projection of the high-frequency antenna (5) partially or completely overlap on the metal floor (6); The low-frequency antenna (1) is composed of a three-layer composite wave-transmitting structure. When a high-frequency electromagnetic wave irradiates the composite wave-transmitting structure of the low-frequency antenna (1), the composite wave-transmitting structure is excited to form a hybrid wave-transmitting structure. The hybrid wave-transmitting structure can introduce two or more resonance points, thereby introducing a broadband transmission window, thereby suppressing the shielding effect of the low-frequency antenna (1) on the high-frequency antenna (5).

2. According to claim 1, a wide-band common-aperture base station antenna array based on a composite wave-transmitting structure is characterized in that: The low-frequency antenna (1) comprises, from top to bottom, a first electromagnetic surface (2), a second electromagnetic surface (3), and a third electromagnetic surface (4), wherein the first electromagnetic surface (2), the second electromagnetic surface (3), and the third electromagnetic surface (4) are separated by air layers with the same spacing; wherein the second electromagnetic surface (3) is a radiation structure of the low-frequency antenna (1).

3. According to claim 2, a wide-band common-aperture base station antenna array based on a composite wave-transmitting structure is characterized in that: The first electromagnetic surface (2) comprises a first dielectric substrate (23) and a first metal square ring (21) printed on the lower surface of the first dielectric substrate (23), wherein the first metal square rings (21) are arranged in an array to form a first array (22).

4. According to claim 2, a wide-band common-aperture base station antenna array based on a composite wave-transmitting structure is characterized in that: The second electromagnetic surface (3) comprises a second dielectric substrate (34) and a composite metal structure (31) printed on the lower surface of the second dielectric substrate (34), wherein the composite metal structure (31) is arranged in an array to form a second array (35), and two diagonally opposite second arrays (35) respectively form a first square ring radiation group (36) and a second square ring radiation group (37) to achieve a ±45° polarized radiation function.

5. According to claim 4, a wide-band common-aperture base station antenna array based on a composite wave-transmitting structure is characterized in that: The composite metal structure (31) comprises a square metal frame (32) and a Jerusalem zigzag strip (33), wherein the Jerusalem zigzag strip (33) is located inside the square metal frame (32), and the two Jerusalem zigzag strips (33) are distributed in a cross-shaped manner.

6. According to claim 4, a wide-band common-aperture base station antenna array based on a composite wave-transmitting structure is characterized in that: A first bifurcated coupling metal strip (8) and a second bifurcated coupling metal strip (9) that cross each other are printed in the middle of the upper surface of the second dielectric substrate (34); the first bifurcated coupling metal strip (8) transfers energy in the first coaxial line (10) to the low-frequency first square ring radiation group (36) in the form of coupling; the second bifurcated coupling metal strip (9) transfers energy in the second coaxial line (11) to the second square ring radiation group (37) in the form of coupling; one end of the first coaxial line (10) is connected to the coupling metal strip of the first bifurcated coupling metal strip (8), and one end of the second coaxial line (11) is connected to the second bifurcated coupling metal strip (9); the other end of the first coaxial line (10) and the other end of the second coaxial line (11) are connected to the feeding end through the metal floor (6) respectively.

7. According to claim 2, a wide-band common-aperture base station antenna array based on a composite wave-transmitting structure is characterized in that: The third electromagnetic surface (4) comprises a first dielectric substrate (43) and a second metal square ring (41) printed on the lower surface of the third dielectric substrate (43), wherein the second metal square rings (41) are arranged in an array to form a third array (42).

8. According to claim 1, a wide-band common-aperture base station antenna array based on a composite wave-transmitting structure is characterized in that: The high-frequency antenna (5) may be single or multiple. When there is a single high-frequency antenna (5), it may be completely placed directly below the low-frequency antenna (1), and the orthographic projection of the low-frequency antenna (1) and the orthographic projection of the high-frequency antenna (5) may completely overlap on the metal floor (6); When the array is composed of a plurality of high-frequency antennas (5), the low-frequency antennas (1) and the high-frequency antennas (5) are arranged in an alternating manner, and the orthographic projection of the low-frequency antenna (1) and the orthographic projection of the high-frequency antenna (5) partially overlap on the metal floor (6).

9. The wide-band common-aperture base station antenna array based on a composite wave-transmitting structure according to claim 8, characterized in that: The high-frequency antenna (5) comprises a fourth dielectric substrate (53) and a fifth dielectric substrate (54), wherein the fifth dielectric substrate (54) is located above the fourth dielectric substrate (51); wherein a rectangular radiation patch (51) is printed on the lower surface of the fourth dielectric substrate (53), and a rectangular parasitic patch (52) is printed on the lower surface of the fifth dielectric substrate (54).

10. The wide-band common-aperture base station antenna array based on a composite wave-transmitting structure according to claim 9, characterized in that: The high-frequency antenna (5) further comprises a first feeding group (56) and a second feeding group (57) printed on the upper surface of the fourth dielectric substrate (54), and both feeding groups feed the rectangular radiation patch (51) by differential feeding to achieve a dual-polarization radiation effect; wherein the first feeding group (56) and the fourth feeding group (57) both comprise two identical bent feeding structures, and the first bent feeding line (561) and the second bent feeding line (562) comprised in the first feeding group (56) couple the third coaxial line (581) and the fourth coaxial line (582) to each other. The energy in the axis (582) is transferred to the rectangular radiation patch (51), and the amplitudes of the feeding excitations in the third coaxial line (581) and the fourth coaxial line (582) are the same, and the phases are opposite; the third bent feed line (571) and the fourth bent feed line (572) included in the second feed group (57) transfer the energy in the fifth coaxial line (591) and the sixth coaxial line (592) to the rectangular radiation patch (51) in the form of coupling, wherein the amplitudes of the feeding excitations in the fifth coaxial line (591) and the sixth coaxial line (592) are the same, and the phases are opposite.

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