Filter integrated antenna structure

Abstract

The application discloses a filter integrated antenna structure and relates to the technical field of communication, wherein the filter integrated antenna structure comprises an antenna assembly and a filter assembly; the antenna assembly comprises a substrate, a radiation patch, a reflecting plate, a feed and a plurality of metal columns; the substrate has opposite first and second ends; the reflecting plate is arranged at the first end of the substrate; the radiation patch is arranged between the first and second ends; the plurality of metal columns are arranged through the substrate in the direction from the second end to the first end to form an electromagnetic shielding cavity; the radiation patch is provided with first and second through holes; and the feed is arranged at the second end of the substrate; the filter assembly is arranged in the electromagnetic shielding cavity and is arranged in a spaced mode with the radiation patch; and the technical scheme provided by the application can not only realize high-density integration of the filter assembly in the antenna, but also improve the filtering performance and the radiation performance of the filter integrated antenna structure.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of communication, in particular to a filter integrated antenna structure. BACKGROUND

[0002] With the rapid development of modern wireless communication technology, the radio frequency (RF) front-end system is facing great demands and challenges in integration, miniaturization, high performance, etc. Antennas and filters play a key role in the radio frequency front-end system, and their collaborative performance deeply affects the communication efficiency and service quality.

[0003] In the traditional radio frequency front-end system layout, antennas and filters are usually designed independently and cascaded, occupying a large amount of structural space and introducing a large amount of interconnection loss, which limits their application in compact and small-sized systems. In recent years, there have been filter antennas that co-design antennas and filters, including cascading method and filter fusion method. The cascading method is to cascade the end of the filter with the same impedance and the signal input end of the antenna for integrated design, and then adjust the matching of the whole. The filter characteristic introduction method is to directly introduce patch slots, short-circuit vias, parasitic patches, open / short-circuit stubs and electromagnetic coupling into the antenna to generate radiation zeros, so that a separate filter is not needed. Both methods have performance interference problems such as insufficient frequency selection effect under high integration and deterioration of radiation pattern. In addition, the current methods also have limitations in applicable antenna types and filter types. These difficulties limit the application of related technologies in modern wireless communication systems with limited space size and strict performance requirements. Therefore, the industry urgently needs new methods and new designs of filter antennas that can improve the integration of the structure while ensuring the high performance of filtering and antenna radiation. SUMMARY

[0004] The main purpose of the present application is to provide a filter integrated antenna structure, which aims to improve the high integration of the filter antenna structure while realizing the high performance of the overall filtering and radiation.

[0005] To achieve the above purpose, the filter integrated antenna structure provided by the present application comprises:

[0006] An antenna assembly includes a substrate, a radiation patch, a reflector plate, a feed, and a plurality of metal columns, the substrate has opposite first and second ends, the reflector plate is disposed at the first end of the substrate, the radiation patch is disposed between the first and second ends, a plurality of the metal columns are spaced apart through the substrate in a direction from the second end to the first end to enclose an electromagnetic shielding cavity, the radiation patch has first and second through holes, the feed is disposed at the second end of the substrate, a portion of the feed passes through the first through hole, the substrate, and the reflector plate in the direction from the second end to the first end, another portion of the feed is arranged in a horizontal direction and above the second through hole, the feed is spaced apart from the radiation patch;

[0007] A filter assembly is disposed in the electromagnetic shielding cavity, the filter assembly is spaced apart from the radiation patch, one of the filter assembly and the feed passes through the second through hole and is connected to the other.

[0008] In an embodiment, the filter assembly includes two filters spaced apart in a horizontal direction, both of the filters are provided with a connection end;

[0009] The reflector plate has two through holes for the connection end to pass through, the aperture of the through hole is larger than the diameter of the connection end, and the connection end is spaced apart from the through hole;

[0010] The feed includes two sub-feeds;

[0011] The first and second through holes are each provided with two through holes for the two sub-feeds to pass through or the two sub-feeds and the two filters to pass through and connect.

[0012] In an embodiment, the connection ends of the two filters are respectively used to connect differential signals with equal amplitudes and a phase difference of 180°, so that the filter integrated antenna structure performs differential feeding.

[0013] In an embodiment, the spacing between the two filters is 0.3 to 0.7 mm.

[0014] In an embodiment, the feed includes a feed column and a microstrip line connected in sequence, a portion of the feed column passes through the first through hole and is electrically connected to a feed point of the reflector plate and the substrate, one end of the microstrip line is connected to the feed column, and the other end is connected to the filter assembly;

[0015] The microstrip line includes first and second connection sections connected in sequence, and the connection between the first and second connection sections is bent.

[0016] In an embodiment, one end of each of the metal columns is connected to the reflecting plate, and the other end is connected to the radiation patch, and a plurality of the metal columns and part of the reflecting plate and part of the radiation patch enclose the electromagnetic shielding cavity.

[0017] In an embodiment, the diameter of the metal column is D, and the D satisfies D < 0.2λ g ;

[0018] The distance between two adjacent metal columns is S, and the S satisfies S < 2D;

[0019] Wherein, λ g is the guided wave wavelength with a center frequency in a preset frequency range.

[0020] In an embodiment, the substrate includes a first dielectric plate, a second dielectric plate, a third dielectric plate, a fourth dielectric plate, a fifth dielectric plate, a sixth dielectric plate, and a seventh dielectric plate, a plurality of dielectric plates are stacked into eight wiring layers, and the eight wiring layers are a first wiring layer, a second wiring layer, a third wiring layer, a fourth wiring layer, a fifth wiring layer, a sixth wiring layer, a seventh wiring layer, and an eighth wiring layer from top to bottom, the radiation patch is arranged on the second wiring layer, the reflecting plate is arranged on the eighth wiring layer, the microstrip line of the feed component is arranged on the first wiring layer, and the first dielectric plate is located between the microstrip line of the feed component and the radiation patch.

[0021] In an embodiment, the filter assembly includes a dual-mode resonator, an input transmission component, and an output transmission component, the dual-mode resonator includes a first resonant component and a second resonant component in a top-down structure, the first resonant component and the second resonant component are connected through a connecting component, the input transmission component is electrically coupled to a first end of the dual-mode resonator, the output transmission component is electrically coupled to a second end of the dual-mode resonator, the input transmission component is arranged on the seventh dielectric plate and sequentially passes through the seventh wiring layer and the eighth wiring layer in a direction from the first end to the second end, the output transmission component is arranged on the sixth dielectric plate and sequentially passes through the sixth wiring layer, the fifth wiring layer, the fourth wiring layer, the third wiring layer, the second wiring layer, and the first wiring layer in a direction from the second end to the first end, and the first resonant component and the second resonant component are arranged on opposite sides of any dielectric plate between the first dielectric plate and the seventh dielectric plate in the direction from the first end to the second end.

[0022] In one embodiment, the first, third, fifth, and seventh dielectric substrates are Rogers RO4350B, and the second, fourth, and sixth dielectric substrates are Rogers RO4450F; the thickness of the first dielectric substrate is 0.168 mm, the thickness of the third, fifth, and seventh dielectric substrates is 0.508 mm, and the thickness of the second, fourth, and sixth dielectric substrates is 0.2 mm.

[0023] And / or, the substrate has a length and width of 20 mm and a height of 2.29 mm.

[0024] The technical solution of this invention, through such a setting, can not only solve the problem of high integration of filter components and antenna components, but also effectively solve the problem of performance degradation due to interference after high integration of filter components and antenna components. Thus, it is possible to achieve high-density integration of filters in a small space inside the antenna while achieving high performance in filtering and radiation. Attached Figure Description

[0025] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0026] Figure 1 This is a schematic diagram of an embodiment of the filter integrated antenna structure provided by the present invention;

[0027] Figure 2 for Figure 1 A schematic diagram of the structure of the antenna assembly;

[0028] Figure 3 for Figure 1 A schematic diagram of the structure of the filter component;

[0029] Figure 4 for Figure 1 A schematic diagram of the disassembled structure of the integrated filtering antenna;

[0030] Figure 5 A cross-sectional view of the filter integrated antenna structure provided by the present invention;

[0031] Figure 6 A simplified schematic diagram of the filter integrated antenna structure provided by the present invention;

[0032] Figure 7A schematic view of the feeding element penetrating the radiating patch and connecting with the reflecting plate is provided in the present application.

[0033] Figure 8 A simulation S parameter and gain schematic view of an embodiment of the antenna assembly provided in the present application is provided.

[0034] Figure 9 A simulation radiation pattern of an embodiment of the antenna assembly provided in the present application is provided.

[0035] Figure 10 A simulation S parameter performance schematic view of an embodiment of the filter assembly provided in the present application is provided.

[0036] Figure 11 A performance schematic view of the filter assembly provided in the present application under the variation of g2 parameter is provided.

[0037] Figure 12 A simulation and measured S parameter and gain performance schematic view of an embodiment of the filter integrated antenna provided in the present application is provided.

[0038] Figure 13 A simulation and measured radiation pattern of the filter integrated antenna provided in the present application in the E plane under 9.4GHz is provided.

[0039] Figure 14 A simulation and measured radiation pattern of the filter integrated antenna provided in the present application in the E plane under 9.8GHz is provided.

[0040] Figure 15 A simulation and measured radiation pattern of the filter integrated antenna provided in the present application in the E plane under 10.4GHz is provided.

[0041] Figure 16 A simulation and measured radiation pattern of the filter integrated antenna provided in the present application in the H plane under 9.4GHz is provided.

[0042] Figure 17 A simulation and measured radiation pattern of the filter integrated antenna provided in the present application in the H plane under 9.8GHz is provided.

[0043] Figure 18 A simulation and measured radiation pattern of the filter integrated antenna provided in the present application in the H plane under 10.4GHz is provided.

[0044] Figure 19 A structure schematic view of another embodiment of the filter integrated antenna structure provided in the present application is provided.

[0045] BRIEF DESCRIPTION OF THE DRAWINGS

[0046] 1, Filter integrated antenna structure; 10, Antenna assembly; 11, Substrate; 111, First dielectric plate; 112, Second dielectric plate; 113, Third dielectric plate; 114, Fourth dielectric plate; 115, Fifth dielectric plate; 116, Sixth dielectric plate; 117, Seventh dielectric plate; 12, Reflective plate; 121, Via hole; 13, Radiating patch; 131, First through hole; 132, Second through hole; 14, Feeding part; 141, Feeding column; 142, Microstrip line; 15, Metal column; 151, Electromagnetic shielding cavity; 20, Filter assembly; 21, Input transmission part; 211, Connection end; 22, Output transmission part; 23, Dual-mode resonator; 231, First resonant part; 232, Second resonant part; 233, Connection part.

[0047] The object, the functional features and the advantages of the present application will be further explained in connection with the embodiments with reference to the drawings. DETAILED DESCRIPTION

[0048] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all the other embodiments obtained by a person of ordinary skill in the art without creative work fall within the protection scope of the present application.

[0049] It should be noted that if the embodiments of the present application involve directionality indication (such as up, down, left, right, front, back, etc.), the directionality indication is only used to explain the relative position relationship, movement condition, etc. between the components in a certain posture, and if the certain posture changes, the directionality indication also changes accordingly.

[0050] In addition, if the embodiments of the present application involve the description of "first", "second" and the like, the description of "first", "second" and the like is only for the purpose of description, and cannot be understood as indicating or implying the relative importance of the indicated technical features or implicitly indicating the number of the indicated technical features. Therefore, the features limited by "first", "second" can explicitly or implicitly include at least one of the features. In addition, "and / or" or "and / or" appearing throughout the text means that the three parallel solutions are included, for example, "A and / or B" includes A solution, or B solution, or A and B solutions are satisfied at the same time. In addition, the technical solutions of each embodiment can be combined with each other, but it must be based on the fact that a person of ordinary skill in the art can realize it, and when the combination of technical solutions appears to be contradictory or unachievable, it should be considered that the combination of technical solutions does not exist, nor is it within the protection scope required by the present application.

[0051] The present application provides a filter integrated antenna structure 1.

[0052] Referring to Figure 1 In an embodiment of the present application, the filter integrated antenna structure 1 comprises an antenna assembly 10 and a filter assembly 20. The antenna assembly 10 comprises a substrate 11, a radiation patch 13, a reflector plate 12, a feed 14 and a plurality of metal columns 15. The substrate 11 has opposite first and second ends. The reflector plate 12 is arranged at the first end of the substrate 11. The radiation patch 13 is arranged between the first and second ends. The plurality of metal columns 15 are arranged through the substrate 11 in a direction from the second end to the first end to enclose an electromagnetic shielding cavity 151. The radiation patch 13 has a first through hole 131 and a second through hole 132. The feed 14 is arranged at the second end of the substrate 11. A portion of the feed 14 is arranged through the first through hole 131 in a direction from the second end to the first end, and the substrate 11 is connected with the reflector plate 12. Another portion of the feed 14 is arranged in a horizontal direction and above the second through hole 132. The feed 14 is arranged spaced apart from the radiation patch 13. The filter assembly 20 is arranged in the electromagnetic shielding cavity 151. The filter assembly 20 is arranged spaced apart from the radiation patch 13. One of the filter assembly 20 and the feed 14 is arranged through the second through hole 132 and connected with the other one.

[0053] The antenna assembly 10 of the technical solution of the present application comprises a substrate 11, a radiation patch 13, a reflector plate 12, a feed 14 and a plurality of metal columns 15. The substrate 11 has opposite first and second ends, specifically, the first and second ends are formed in a thickness direction of the substrate 11, the first end is located at a lower side, and the second end is located at an upper side. In the embodiment, it is worth mentioning that the substrate 11 is arranged in multiple layers. The reflector plate 12 is arranged at the first end. The radiation patch 13 is arranged between the first and second ends, that is, arranged between the multiple layers of the substrate 11, and arranged spaced apart from the reflector plate 12. A portion of the feed 14 is arranged through the radiation patch 13 and the substrate 11 and connected with the reflector plate 12. Another portion of the feed 14 is arranged on the substrate 11 and arranged spaced apart from the radiation patch 13. In order to enable the feed 14 to smoothly pass through the radiation patch 13 and the substrate 11, in the embodiment, a first through hole 131 is formed in the radiation patch 13. When the feed 14 is formed, a portion of the feed 14 is arranged through the first through hole 131 and the substrate 11 in a direction from the second end to the first end, and the substrate 11 is connected with the reflector plate 12. It is worth noting that the aperture of the first through hole 131 is larger than the diameter of the portion of the feed 14 arranged through the first through hole 131, so that the portion of the feed 14 arranged through the first through hole 131 is kept in a spaced-apart state with the radiation patch 13.

[0054] The power supply component 14 that passes through the substrate 11 can be integrally set during the processing of the substrate 11. For example, when the substrate 11 is formed by stacking multiple layers, the power supply component 14 can be formed by interconnecting the conductive parts set on multiple substrates 11. The specific setting of the power supply component 14 is not limited.

[0055] In this embodiment, the filter assembly 20 is fabricated together with the substrate 11, that is, the filter assembly 20 is fabricated together with the substrate 11 using a similar processing method as described above, so that the filter assembly 20 is disposed within the substrate 11, thereby reducing the volume of the filter integrated antenna structure 1. However, the problem of poor filtering effect still exists. In this embodiment, a plurality of metal pillars 15 are provided on the substrate 11, and the plurality of metal pillars 15 are arranged at intervals between each other, forming an electromagnetic shielding cavity 151 on the substrate 11, and the filter assembly 20 is disposed within the electromagnetic shielding cavity 151. In order to enable the filter assembly 20 to be connected to the power supply component 14, in this embodiment, a second through hole 132 is also provided in the radiating patch 13, and another part of the power supply component 14 is arranged horizontally and located above the second through hole 132. In order to connect the other part of the power supply component 14 and the filter assembly 20, one of the power supply component 14 or the filter assembly 20 can be extended along the thickness direction of the substrate 11 until it is connected to the other. Of course, both can be extended at the same time and the connection can be completed in the through hole. There are no restrictions on this.

[0056] It is worth mentioning that in this embodiment, the signal flows from the filter component 20, and after passing through the filter component 20, it is connected to the reflector 12 through the feeder 14, thereby exciting the radiating patch 13 to radiate electromagnetic waves.

[0057] In this embodiment, the filter component 20 can be one filter or multiple filters. For example, such as Figure 19 As shown, when the filter assembly 20 is a single filter, the filter is disposed on the substrate 11 in the manner described above. This filter is located within the electromagnetic shielding cavity 151. In this embodiment, there is also a single feed element 14. The filter connects to the reflector 12 via the single feed element 14. The electromagnetic shielding cavity 151 can shield external interfering electromagnetic waves, thereby improving the filter's filtering performance. Furthermore, since the filter is integrally formed with the substrate 11, it can be highly integrated with the antenna assembly 10 and the substrate 11. This configuration results in a filter-integrated antenna structure with high integration, high filtering performance, and high radiation performance.

[0058] By setting the filter integrated antenna structure 1 in the above manner, not only can the problem of the filter component 20 and the antenna component 10 being difficult to integrate to a high degree can be solved, but the problem of performance degradation due to interference after the filter component 20 and the antenna component 10 are highly integrated can also be effectively solved.

[0059] In one embodiment, such as Figures 1 to 4 As shown, the filter assembly 20 includes two filters spaced apart in the horizontal direction, each filter having a connection end 211; the reflector 12 has two through holes 121, each for the connection end 211 to pass through, the diameter of the through hole 121 being larger than the diameter of the connection end 211, and the connection segment being spaced apart from the through hole 121; the feed element 14 includes two sub-feed elements 14; the first through hole 131 and the second through hole 132 each have two, for the two sub-feed elements 14 or the two sub-feed elements 14 and the two filters to pass through and connect. In this embodiment, a differential filter integrated antenna structure 1 is proposed. The filter assembly in this embodiment consists of two filters. In this embodiment, the filter assembly 20 includes two filters spaced apart in the electromagnetic shielding cavity 151 in the horizontal direction, wherein each filter has a connection end 211, which is mainly used for connecting external signal lines. To facilitate the connection of the two filters to external signal lines, in this embodiment, two vias 121 are provided on the reflector 12. The two vias 121 correspond to the two connection ends 211 respectively, and are used to accommodate or extend the two connection ends 211 from the substrate 11. It should be noted that the diameter of the via 121 is larger than the diameter of the connection section, so that when the connection end 211 is accommodated in the via 121 or extends out of the via 121, it is spaced apart from the via 121, that is, spaced apart from the reflector 12. In this embodiment, the feed element 14, serving as the feed structure, includes two sub-feed elements 14. The radiating patch 13 has two first through holes 131 and two second through holes 132. The two first through holes 131 are used for a portion of each of the two sub-feed elements 14 to pass through, and the two second through holes 132 are used for the ends of the two sub-feed elements 14 or the two filters to extend away from the connection end 211. This allows the two filters to be connected to the reflector 12 via the two sub-feed elements 14, thereby exciting the radiating patch 13 to radiate electromagnetic waves. In this embodiment, the two filters, two through holes 121, two first through holes 131 and second through holes 132, and two sub-feed elements 14 are symmetrically arranged in the horizontal direction.

[0060] In an embodiment, the connection terminals 211 of the two filters are respectively used to connect equal-amplitude differential signals with 180° phase difference, so that the filter integrated antenna structure is fed differentially. In this embodiment, equal-amplitude differential signals with 180° phase difference are connected from the connection terminals 211 of the two filters, pass through the filters in the shielded cavity, pass through the radiation patch 13, and finally reach the reflector plate 12 to excite the radiation patch 13, thereby realizing differential feeding to achieve the high gain and low cross-polarization performance inherent to differential antennas. For example, as shown in Figures 13 to 18 , the simulated and measured radiation patterns at 9.4 GHz, 9.8 GHz, and 10.4 GHz are shown, showing good unidirectional radiation. The simulated E-plane and H-plane cross-polarization levels are both less than -40 dB, and the measured cross-polarization levels are both less than -23 dB. The simulated and measured 3-dB beamwidths are both greater than 77°, and the front-to-back ratio is less than 20 dB. Compared with conventional patch antennas, the radiation patterns in the E-plane and H-plane are more symmetrical, and the cross-polarization level is improved.

[0061] In an embodiment, the filter assembly 20 uses two identical double-layer coupled filters with a spacing g2. When in operation, equal-amplitude differential signals with 180° phase difference are applied to the connection terminals 211 of the two filters. For example, as shown in Figure 10 , in this embodiment, the S parameters of the filter assembly 20 are shown, with a center frequency of 9.8 GHz and an S11≤-10 dB bandwidth of 11%. The return loss of the input port is better than 27 dB, the insertion loss is less than 0.6 dB, and the passband ripple is less than 0.2 dB. The low insertion loss is also partly due to the effective reduction of radiation loss and interference by the shielded cavity. The transmission zeros TZ1-TZ5 are located at 7.6, 8.8, 11.5, 14.6, and 17.1 GHz, achieving high selectivity and excellent out-of-band suppression performance, with an out-of-band suppression bandwidth of 1.6f0.

[0062] In an embodiment, as shown in Figure 11 , the spacing between the two filters is 0.3-0.7 mm. It should be emphasized that the excellent performance of the two filters is also due to the reasonable selection of the above parameter g2. g2 represents the spacing between the two filters. To further illustrate this point, different g2 values are simulated, as shown in Figure 11 . Four parameters are selected: g2=0.7, 0.5, 0.3, and 0.1 mm. It can be observed that when g2 is too small, there is coupling between the two filters, which makes the filtering performance worse, as shown by the decrease in the right selectivity of the S parameter S21. When g2 reaches 0.5 mm and continues to increase, the filtering performance tends to be stable.

[0063] In an embodiment, as shown in Figure 1 and Figure 7As shown, the feeding member 14 includes a feeding post 141 and a microstrip line 142 connected in sequence, a part of the feeding post 141 is electrically connected with the feeding point of the substrate 11 and the reflecting plate 12 through the first through hole 131, one end of the microstrip line 142 is connected with the feeding post 141, and the other end is connected with the filter assembly 20; the microstrip line 142 includes a first connecting section and a second connecting section connected in sequence, and the connecting position of the first connecting section and the second connecting section is arranged in a bending manner. In the embodiment, the feeding member 14 mainly includes the feeding post 141 and the microstrip line 142 connected in sequence, wherein the feeding post 141 is part of the above-mentioned embodiment, and the microstrip line 142 is another part of the above-mentioned embodiment. The feeding post 141 is mainly used for electrical connection through the first through hole 131 and the feeding point of the substrate 11 and the reflecting plate 12, and the microstrip line 142 is electrically connected with the feeding post 141 at one end and is located above the second through hole 132 at the other end. In the embodiment, the microstrip line 142 includes a first connecting section and a second connecting section (not shown in the figure), and the microstrip line 142 is arranged in this way to facilitate the laying of the plurality of metal columns 15 in the above-mentioned embodiment, so as to prevent the microstrip line 142 from interfering with the arrangement of the plurality of metal columns 15.

[0064] In an embodiment, one end of each of the metal columns 15 is connected with the reflecting plate 12, and the other end is connected with the radiation patch 13, and the plurality of metal columns 15 and part of the reflecting plate 12 and part of the radiation patch 13 form the electromagnetic shielding cavity 151.

[0065] In an embodiment, the diameter of the metal column 15 is D, and the D satisfies D < 0.2λ g ; the distance between two adjacent metal columns 15 is S, and the S satisfies S ≤ 2D; wherein λ g is the guided wave wavelength of the center frequency in the preset frequency range.

[0066] It is worth noting that the preset frequency range is set in advance by the researchers, and in the embodiment, the preset frequency range is the X-band frequency range, and according to the IEEE521-2002 standard, the frequency is between 8GHz and 12GHz.

[0067] In an embodiment, as Figure 5As shown, the substrate 11 includes a first dielectric plate 111, a second dielectric plate 112, a third dielectric plate 113, a fourth dielectric plate 114, a fifth dielectric plate 115, a sixth dielectric plate 116, and a seventh dielectric plate 117, and a plurality of dielectric plates are stacked to form eight wiring layers, the eight wiring layers are a first wiring layer, a second wiring layer, a third wiring layer, a fourth wiring layer, a fifth wiring layer, a sixth wiring layer, a seventh wiring layer, and an eighth wiring layer from top to bottom, the radiation patch 13 is arranged on the second wiring layer, the reflecting plate 12 is arranged on the eighth wiring layer, the feed 14 is arranged on the first wiring layer, and the first dielectric plate 111 is located between the microstrip line 142 and the radiation patch 13. The number of the substrate 11 is seven, and a plurality of substrates 11 are stacked to include the first dielectric plate 111, the second dielectric plate 112, the third dielectric plate 113, the fourth dielectric plate 114, the fifth dielectric plate 115, the sixth dielectric plate 116, and the seventh dielectric plate 117, and a plurality of the substrate 11 are stacked to form eight wiring layers, which are a first wiring layer, a second wiring layer, a third wiring layer, a fourth wiring layer, a fifth wiring layer, a sixth wiring layer, a seventh wiring layer, and an eighth wiring layer (not shown in the figure), wherein the first wiring layer to the seventh wiring layer are sequentially arranged above the first dielectric plate 111 to the seventh dielectric plate 117 from the second end to the first end of the substrate 11, and the eighth wiring layer is arranged below the seventh dielectric plate 117. Specifically, since the second dielectric plate 112, the fourth dielectric plate 114, and the sixth dielectric plate 116 are flexible substrates, the above-mentioned wiring layers are arranged above and below the first dielectric plate 111, the third dielectric plate 113, the fifth dielectric plate 115, and the seventh dielectric plate 117. In this embodiment, the radiation patch 13 is arranged on the second wiring layer, that is, between the first dielectric plate 111 and the second dielectric plate 112, the reflecting part is arranged on the eighth wiring layer, that is, below the seventh dielectric plate, and part of the feed 14 is arranged on the first wiring layer, that is, above the first dielectric plate 111. In this embodiment, the signal transmission line is input from the connection end 211 of the two filters, passes through the filter assembly 20 in the electromagnetic shielding cavity 151 to the feed 14 through the radiation patch 13, and finally reaches the reflecting plate 12 through the feed 14 to excite the radiation patch 13, Figure 5 The arrow path is the direction of electromagnetic energy flow.

[0068] In an embodiment, as Figure 3As shown, the filter assembly 20 includes a dual-mode resonator 23, an input transmission line 21 and an output transmission line 22, the dual-mode resonator 23 includes a first resonant component 231 and a second resonant component 232 in an up-down structure, the first resonant component 231 and the second resonant component 232 are connected through a connecting piece, the input transmission line 21 is electrically coupled with a first end of the dual-mode resonator 23, the output transmission line 22 is electrically coupled with a second end of the dual-mode resonator 23, the input transmission line 21 is arranged on the seventh dielectric plate 117 and sequentially passes through the seventh wiring layer and the eighth wiring layer in the direction from the first end to the second end, the output transmission line 22 is arranged on the sixth dielectric plate 116 and sequentially passes through the sixth wiring layer, the fifth wiring layer, the fourth wiring layer, the third wiring layer, the second wiring layer and the first wiring layer in the direction from the second end to the first end, the first resonant component 231 and the second resonant component 232 are arranged on the opposite side of any dielectric plate between the first dielectric plate 111 and the seventh dielectric plate 117 in the direction from the first end to the second end. In this embodiment, the dual-mode resonator 23 of the filter assembly 20 adopts a three-dimensional structure in an up-down structure, compared with the traditional planar dual-mode resonator 23, the coupling between the source and the load and the mutual coupling between the up-down structures are introduced, thus, the additional transmission zero is introduced, the selectivity and the out-of-band suppression capability of the filter are improved, and the size of the filter assembly 20 is reduced to a certain extent. In this embodiment, as shown in Figure 3 and Figure 5 As shown, the input transmission line 21 and the output transmission line 22 each include a vertical feeding part and a coupling part, the vertical feeding part is arranged in the direction from the first end to the second end, and the coupling part is laid in the horizontal direction, the coupling part of the input transmission line 21 is arranged on the seventh dielectric plate 117, and the vertical feeding part sequentially passes through the seventh wiring layer and the eighth wiring layer in the direction from the first end to the second end, the coupling part of the output transmission line 22 is arranged on the sixth dielectric plate, and the vertical feeding part sequentially passes through the sixth wiring layer, the fifth wiring layer, the fourth wiring layer, the third wiring layer, the second wiring layer and the first wiring layer in the direction from the second end to the first end. In this embodiment, the first resonant component 231 and the second resonant component 232 can be arranged on the opposite side of any dielectric plate between the first dielectric plate 111 and the seventh dielectric plate 117 in the direction from the first end to the second end, for example, can be arranged on the opposite side of the sixth dielectric plate 116, the first resonant component 231 is arranged on the seventh wiring layer, and the second resonant component 232 is arranged on the sixth wiring layer, or the first resonant component 231 is arranged on the sixth wiring layer, and the second resonant component 232 is arranged on the seventh wiring layer, for another example, can be arranged on the opposite side of the fifth dielectric plate 115, the first resonant component 231 is arranged on the fifth wiring layer, and the second resonant component 232 is arranged on the sixth wiring layer, or the first resonant component 231 is arranged on the sixth wiring layer, and the second resonant component 232 is arranged on the fifth wiring layer, and no more limitation is made to this.

[0069] In one embodiment, the first dielectric substrate 111, the third dielectric substrate 113, the fifth dielectric substrate 115, and the seventh dielectric substrate 117 are Rogers RO4350B, and the second dielectric substrate 112, the fourth dielectric substrate 114, and the sixth dielectric substrate 116 are Rogers RO4450F; the thickness of the first dielectric substrate 111 is 0.168 mm, the thickness of the third dielectric substrate 113, the fifth dielectric substrate 115, and the seventh dielectric substrate 117 is 0.508 mm, and the thickness of the second dielectric substrate 112, the fourth dielectric substrate 114, and the sixth dielectric substrate 116 is 0.2 mm; and / or, the length and width of the substrate 11 are both 20 mm, and the height is 2.29 mm. In this embodiment, multilayer PCB technology is used for physical manufacturing, and the substrates 11 used are Rogers RO4350B and RO4450F, with relative permittivity of 3.66 and 3.52, and loss tangents of 0.0037 and 0.004, respectively. More specifically, for Figure 5 In the structure, substrates 11Med1 to Med4 use Rogers RO4350B, and substrates 11PP1 to PP3 use Rogers RO4450F. The thickness of the first dielectric substrate 111 is 0.168 mm, the thickness of the third dielectric substrate 113, the fifth dielectric substrate 115, and the seventh dielectric substrate 117 is 0.508 mm, and the thickness of the second dielectric substrate 112, the fourth dielectric substrate 114, and the sixth dielectric substrate 116 is 0.2 mm. The length and width of substrate 11 are both 20 mm, and the height is 2.29 mm. The length of substrate 11 is... Figure 1 LG1, width WG1, height is Figure 5 H1 in the diagram. The overall dimensions of the patch antenna are referenced to 0.44λ. g ×0.42λ g ×0.1λ g Design, where λ g The wavelength is the guide wave. The dimensional parameters of the filter integrated antenna structure 1 are shown in the table below:

[0070]

[0071] In one embodiment, such as Figure 8 As shown, the performance of antenna assembly 10 is presented, including reflection parameter S11 and gain. It operates at a center frequency of 9.8 GHz, ranging from 9.1 to 10.5 GHz, with a bandwidth of 14% where S11 ≤ -10 dB. The in-band gain is flat, approximately 7.3 dBi. Figure 9The simulated radiation pattern at 9.8 GHz is shown, which exhibits good unidirectional radiation, 3 dB beamwidth greater than 77°, and front-to-back ratio better than 22 dB. Compared with the conventional patch antenna, the E-plane and H-plane patterns are more symmetrical. The cross-polarization level is better than -40 dB due to the differential feed, thus, it cannot be observed in the figure.

[0072] In an embodiment, the filter assembly 20 employs two identical dual-layer coupled filters with a spacing of g2. In operation, equal-amplitude differential signals with a 180-degree phase difference are applied to the connection terminals of the filters. Figure 10 The S-parameters of the filter assembly 20 are shown, which has a center frequency of 9.8 GHz and a bandwidth of S11≤-10 dB of 11%. The return loss of the input port is better than 27 dB, the insertion loss is less than 0.6 dB, and the passband ripple is less than 0.2 dB. The low insertion loss is also partly due to the shielded cavity effectively reducing the radiation loss and interference. Transmission zeros TZ1-TZ5 are located at 7.6, 8.8, 11.5, 14.6, and 17.1 GHz, achieving high selectivity and superior out-of-band rejection performance, with an out-of-band rejection bandwidth of 1.6f0.

[0073] In an embodiment, as Figure 12 The S-parameters and gain of the prototype simulation and measurement of the filter-integrated antenna structure 1 employing the above embodiment are shown. The center frequency operates at 9.8 GHz. The measured gain in-band is about 6.4 dBi. Compared with the 7.3 dBi gain of the antenna assembly 10, the total loss of the filter insertion loss, interconnection loss, and measurement deviation is 0.9 dB. The frequencies of the five transmission zeros are in good agreement with the performance of the filter assembly 20, and the filter selectivity and out-of-band rejection performance are superior, with an out-of-band rejection bandwidth of 1.6f0.

[0074] Figures 13 to 18The simulated and measured radiation patterns at 9.4 GHz, 9.8 GHz, and 10.4 GHz are given, respectively, showing good unidirectional radiation. The simulated E-plane and H-plane cross-polarization levels are both below -40 dB, and the measured cross-polarization levels are all below -23 dB. The simulated and measured 3-dB beamwidths are both greater than 77°, and the front-to-back ratios are less than 20 dB. Compared with the conventional patch antenna, the radiation patterns in the E-plane and H-plane are more symmetrical, and the cross-polarization level is improved. These improvements show that the performance of the integrated differential filter-integrated antenna structure still maintains the superior performance of the antenna component 10 and the filter component 20 before integration, achieving high integration and compact size while exhibiting superior filtering performance (excellent port matching, high selectivity, wide stopband, and low loss, etc.) and excellent radiation characteristics (high gain, unidirectional radiation, high symmetry, low cross-polarization level, low front-to-back ratio, wide beamwidth, etc.). We predict that the proposed differential patch filter-integrated antenna design, with excellent filtering and antenna performance in such a compact structure, will have great potential for modern wireless communication systems (e.g., the sixth generation (6G) mobile communication).

[0075] The above merely describes exemplary embodiments of the present application, and is not intended to limit the patent scope of the present application. Any equivalent structural transformation made according to the content of the present application specification and drawings, or direct / indirect application in other related technical fields, falls within the patent protection scope of the present application.

Claims

1. A filter integrated antenna structure, characterized by, The application relates to an antenna assembly and a filter assembly. The antenna assembly comprises a substrate, a radiation patch, a reflecting plate, a feed and a plurality of metal columns, the substrate has opposite first and second ends, the reflecting plate is arranged at the first end of the substrate, the radiation patch is arranged between the first and second ends, a plurality of the metal columns are arranged through the substrate in a direction from the second end to the first end to form an electromagnetic shielding cavity, the radiation patch has first and second through holes, the feed is arranged at the second end of the substrate, a part of the feed is arranged through the first through hole, the substrate and the reflecting plate in the direction from the second end to the first end, and another part of the feed is arranged in a horizontal direction and above the second through hole, the feed is arranged apart from the radiation patch, one of the filter assembly and the feed passes through the second through hole and is connected with the other. The filter assembly comprises two filters arranged apart in a horizontal direction, and the two filters are each provided with a connecting end.

2. The filtered integrated antenna structure of claim 1, wherein, The reflecting plate has two through holes for the connecting ends to pass through, the through holes have a diameter larger than that of the connecting ends, and the connecting ends are arranged apart from the through holes. The feed comprises two sub-feeds. The first and second through holes are each provided with two through holes for the two sub-feeds or the two sub-feeds and the two filters to pass through and be connected. The connecting ends of the two filters are respectively used for connecting equal-amplitude differential signals with a phase difference of 180 degrees, so that the antenna assembly structure is differentially fed.

3. The filtering integrated antenna structure of claim 2, wherein, The spacing between the two filters is 0.3-0.7 mm.

4. The filtering integrated antenna structure of claim 2, wherein, The feed comprises a feed column and a microstrip line connected in sequence, a part of the feed column passes through the first through hole and is electrically connected with a feed point of the reflecting plate, one end of the microstrip line is connected with the feed column, and the other end is connected with the filter assembly.

5. The filtering integrated antenna structure of claim 1, wherein, The microstrip line comprises a first connecting section and a second connecting section connected in sequence, and the connecting position of the first and second connecting sections is bent. One end of each of the metal columns is connected with the reflecting plate, and the other end is connected with the radiation patch, and the plurality of metal columns and part of the reflecting plate and part of the radiation patch form the electromagnetic shielding cavity.

6. The filtered integrated antenna structure of claim 1, wherein, The spacing between two adjacent metal columns is S, and the S satisfies S<=2D.

7. The filtering integrated antenna structure of claim 6, wherein, The diameter of the metal post is D, which satisfies D < 0.2λ g ; ​ where λ g is a guided wave wavelength at a center frequency within a predetermined frequency range.

8. The filtering integrated antenna structure according to any one of claims 1 to 7, wherein, The substrate comprises a first dielectric plate, a second dielectric plate, a third dielectric plate, a fourth dielectric plate, a fifth dielectric plate, a sixth dielectric plate and a seventh dielectric plate, a plurality of dielectric plates are stacked into eight wiring layers, the eight wiring layers are a first wiring layer, a second wiring layer, a third wiring layer, a fourth wiring layer, a fifth wiring layer, a sixth wiring layer, a seventh wiring layer and an eighth wiring layer from top to bottom, the radiation patch is arranged on the second wiring layer, the reflecting plate is arranged on the eighth wiring layer, the microstrip line of the feed part is arranged on the first wiring layer, and the first dielectric plate is located between the microstrip line of the feed part and the radiation patch.

9. The filtering integrated antenna structure of claim 8, wherein, The filter assembly comprises a dual-mode resonator, an input transmission line and an output transmission line, the dual-mode resonator comprises a first resonant component and a second resonant component in an up-down structure, the first resonant component and the second resonant component are connected through a connecting piece, the input transmission line is electrically coupled with a first end of the dual-mode resonator, and the output transmission line is electrically coupled with a second end of the dual-mode resonator, the input transmission line is arranged on the seventh dielectric plate and sequentially passes through the seventh wiring layer and the eighth wiring layer in a direction from the first end to the second end, the output transmission line is arranged on the sixth dielectric plate and sequentially passes through the sixth wiring layer, the fifth wiring layer, the fourth wiring layer, the third wiring layer, the second wiring layer and the first wiring layer in a direction from the second end to the first end, and the first resonant component and the second resonant component are arranged on opposite sides of any dielectric plate between the first dielectric plate and the seventh dielectric plate in the direction from the first end to the second end.

10. The filtering integrated antenna structure of claim 8, wherein, The first dielectric plate, the third dielectric plate, the fifth dielectric plate and the seventh dielectric plate are Rogers RO4350B, the second dielectric plate, the fourth dielectric plate and the sixth dielectric plate are Rogers RO4450F, the thickness of the first dielectric plate is 0.168 mm, the thicknesses of the third dielectric plate, the fifth dielectric plate and the seventh dielectric plate are all 0.508 mm, and the thicknesses of the second dielectric plate, the fourth dielectric plate and the sixth dielectric plate are all 0.2 mm. Alternatively, the length and the width of the substrate are both 20 mm, and the height is 2.29 mm.

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