Multifunctional passive device integrating antenna array and multichannel filter

Abstract

The invention provides a multifunctional passive device integrating an antenna array and a multi-channel filter, which belongs to the technical field of millimeter wave communication antennas and comprises a metal substrate, a high-frequency antenna array feed port and a low-frequency filter feed port, a pyramid horn array, a first vertical waveguide section, a cavity layer, a second vertical waveguide section and an H-shaped waveguide power dividing feed network are sequentially arranged in the metal base body from top to bottom. The low-frequency filter port is connected to the cavity layer, and the high-frequency antenna array feed port is arranged at the input port of the H-shaped waveguide power division feed network. According to the invention, integration of multiple filtering channels is realized, and the integration level and the structure multiplexing rate of a multifunctional device are improved; the antenna and the filter are integrated by means of the frequency selection characteristic of the electromagnetic band gap structure, the natural high isolation characteristic between the antenna and the filter is provided, an additional isolation structure is prevented from being added, and the design complexity is reduced.

Description

Technical Field

[0001] This invention relates to the field of millimeter-wave communication antenna technology, and more specifically to a multifunctional passive device that integrates an antenna array and a multi-channel filter. Background Technology

[0002] Multifunctional radio frequency (RF) devices integrate functions such as radiation, filtering, and power distribution into a single structure, enabling flexible switching of functions according to different application requirements. This significantly improves the integration of wireless communication systems, reduces device costs, and expands application scenarios. Antennas and filters, as indispensable core passive components in the RF front end, are numerous and occupy a large amount of system space; therefore, their functional integration has become one of the current research hotspots.

[0003] To achieve multifunctional integration, countless types of antennas and filters can be used to design RF passive devices. The main design methods can be broadly categorized as follows. The first category is unstructured multiplexing, where the filter is typically designed into the non-radiating region of the antenna, or the filter and antenna structures are integrated in parallel through port multiplexing. However, in this method, the filter and antenna structures remain independent, failing to achieve system miniaturization and improved integration. With technological advancements, increasing research focuses on implementing filter designs through partial or complete multiplexing of antenna structures. One common approach is to multiplex the antenna's radiator or feed structure as the filter's coupling structure and resonator; another approach is to completely multiplex the antenna structure to design the filter, while fully sharing the filter's input and output ports with the antenna ports.

[0004] These multifunctional integrated passive devices are mostly designed for microwave frequencies. However, when the frequency band is extended to the millimeter-wave band, large-scale antenna arrays are usually required to provide high-gain radiation, beamforming, and other functions, which poses a challenge to existing design methods, especially in the case of large-scale antenna arrays that integrate filters into millimeter-wave wireless systems.

[0005] In the millimeter-wave band, applications such as high-capacity backhaul, wireless access, and satellite links place stringent demands on the performance of high-gain fixed-beam antennas. Compared to substrate-integrated arrays, all-metal antenna arrays employing air-filled waveguide feed networks significantly reduce losses while maintaining high power capacity and mechanical robustness. To achieve broadband and high-gain radiation characteristics, some arrays employ broadband structural designs, including fully parallel feed networks, vertical interconnect structures, and 1-to-4 cavity power dividers, to excite broadband all-metal radiators such as horn antennas, magnetoelectric dipoles, and cavity-backed antennas. Notably, the cavity power dividers in the array provide a natural channel for cavity resonators multiplexed as filters.

[0006] Therefore, given the significant space required for large-scale millimeter-wave antenna arrays in system layout, integrating multi-channel bandpass filters into a multiplexed array feed structure and applying them to the microwave RF front-end will significantly improve the compactness and versatility of dual-band wireless systems. A key challenge in designing this multiplexed structure lies in achieving the required performance for each while ensuring sufficient isolation between the filter and antenna functions. Summary of the Invention

[0007] The purpose of this invention is to address the problems of existing multifunctional devices integrating antennas and filters, such as the inability to integrate two-dimensional arrays and filters in the millimeter-wave band, the difficulty in integrating multiple filter channels, and the difficulty in achieving efficient isolation between functions. This invention provides a multifunctional passive device integrating an antenna array and a multi-channel filter to solve at least one of the technical problems mentioned above.

[0008] To achieve the above objectives, the present invention adopts the following technical solution:

[0009] This invention provides a multifunctional passive device integrating an antenna array and a multi-channel filter, comprising: a metal substrate, a high-frequency antenna array feed port and a low-frequency filter feed port disposed outside the metal substrate;

[0010] The internal structure of the metal substrate, from top to bottom, consists of a pyramidal horn array, a first vertical waveguide segment, a cavity layer, a second vertical waveguide segment, and an H-type waveguide power divider feed network.

[0011] The low-frequency filter port is connected to the cavity layer, and the high-frequency antenna array feed port is located at the input port of the H-type waveguide power divider feed network.

[0012] Furthermore, the cavity layer includes a multifunctional cavity, an outer cavity, a capacitor branch disposed above the edge of the outer cavity, a first coupling window structure and a second coupling window structure connecting the multifunctional cavities and the multifunctional cavity and the outer cavity; the first coupling window structure is located at both ends of the narrow side of the multifunctional cavity, and the second coupling window structure is located on both sides of the wide side of the multifunctional cavity.

[0013] Furthermore, at both ends of the narrow side of each multifunctional cavity, three metal pillars loaded on the bottom are arranged in a triangle, with each metal pillar maintaining a certain air gap with the top of the cavity; the bottom metal pillars and the top of the cavity together constitute the first electromagnetic bandgap structure.

[0014] Furthermore, three rows of metal pillars are periodically loaded at the bottom of the second coupling window structure. These metal pillars have a certain air gap with the top of the second coupling window structure. The three rows of metal pillars and the top of the second coupling window structure together constitute the second electromagnetic bandgap structure. Tuning metal pillars are loaded on the top of each external cavity.

[0015] Furthermore, a coupling metal ridge is loaded in the first coupling window structure, and a second electromagnetic bandgap structure is loaded in the second coupling window structure. The coupling strength between the cavities is adjusted by adjusting the length of the coupling window and the height of the coupling metal ridge in the filter.

[0016] Furthermore, each filter main structure is cascaded through a multifunctional cavity, with the external cavities serving as input and output cavities respectively; between the cavities, a first coupling window structure and a second coupling window structure are used for connection in the horizontal and vertical directions.

[0017] Furthermore, an 8×8 array of horn antennas was adopted; each subarray adopted a 2×2 array size, consisting of 4 pyramidal horn radiators, 4 first vertical waveguide sections, 1 multifunctional cavity, and 1 second vertical waveguide section; electromagnetic waves were input from the high-frequency antenna array feed port and transmitted to each subarray through the H-type power divider feed network, thereby jointly realizing electromagnetic wave radiation.

[0018] Furthermore, the filtering function achieves low-frequency multi-channel filter integration through the multiplexing cavity layer. In the multifunctional cavity, the first electromagnetic bandgap structure is equivalent to a slow-wave loading structure.

[0019] Furthermore, for the second coupling window structure on both sides of the wide side of the multifunctional cavity, the second electromagnetic bandgap structure loaded thereon is equivalent to a slow-wave loading structure, which enhances the coupling strength by increasing the capacitance effect.

[0020] Furthermore, the resonant frequency of the external cavity is adjusted by loading a tuning metal pillar at the top, while the capacitive stubs on the edge of the external cavity improve the out-of-band rejection capability of the filter.

[0021] The beneficial effects of this invention are as follows: It realizes the integration of two-dimensional antenna arrays and filters in the millimeter-wave band. Large-scale antenna arrays occupy a lot of space in the front end of millimeter-wave wireless communication systems. It realizes the integration of microwave band filters, improves the system integration level and expands the system application scenarios. It realizes the integration of multiple filtering channels, breaking through the bottleneck that existing multifunctional devices can only integrate a single filtering channel, and improves the integration level and structural reuse rate of multifunctional devices. While realizing the frequency selection characteristics of the electromagnetic bandgap structure, it provides the inherent high isolation characteristics between the antenna and the filter, avoiding the need to add additional isolation structures and reducing design complexity.

[0022] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and will become apparent from the description or may be learned by practice of the invention. Attached Figure Description

[0023] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the description of the embodiments 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 these drawings without creative effort.

[0024] Figure 1 This is a three-dimensional structural diagram of the multifunctional passive device integrating an antenna array and a multi-channel filter as described in an embodiment of the present invention, viewed from the front.

[0025] Figure 2 This is a rear-view perspective view of the multifunctional passive device integrating an antenna array and a multi-channel filter as described in an embodiment of the present invention.

[0026] Figure 3 This is an exploded view of the internal structure of the multifunctional passive device integrating an antenna array and a multi-channel filter as described in an embodiment of the present invention.

[0027] Figure 4 This is a side view of the internal structure of the multifunctional passive device integrating an antenna array and a multi-channel filter as described in an embodiment of the present invention.

[0028] Figure 5 This is a three-dimensional orthographic projection of the cavity layer described in an embodiment of the present invention.

[0029] Figure 6 This is a perspective view of the cavity layer structure described in an embodiment of the present invention.

[0030] Figure 7 This is a schematic diagram of the two coupling methods between the dual-function cavities described in an embodiment of the present invention.

[0031] Figure 8 This is a schematic diagram of the design method for integrating multi-channel filters according to an embodiment of the present invention.

[0032] Figure 9 The figure shows the simulation and test results of the S-parameters of the multifunctional passive device integrating antenna array and multi-channel filter described in the embodiment of the present invention in the millimeter-wave band.

[0033] Figure 10 The figure shows the simulation and test results of the gain of the multifunctional passive device integrating antenna array and multi-channel filter described in the embodiment of the present invention in the millimeter-wave band.

[0034] Figure 11 The image shows the simulation and test results of the E-plane radiation pattern of the multifunctional passive device integrating an antenna array and a multi-channel filter as described in the embodiments of the present invention at 30 GHz.

[0035] Figure 12 The above diagram shows the simulation and test results of the H-plane radiation pattern of the multifunctional passive device integrating antenna array and multi-channel filter described in the embodiment of the present invention at 30 GHz.

[0036] Figure 13 The figure shows the S-parameter simulation and test results of the multifunctional passive device integrating antenna array and multi-channel filter described in the embodiment of the present invention in a sixth-order filter in the microwave band.

[0037] Figure 14 The figure shows the S-parameter simulation and test results of the multifunctional passive device integrating antenna array and multi-channel filter described in the embodiment of the present invention in the microwave band tenth-order filter.

[0038] Figure 15 This is a schematic diagram of the isolation curve between the filter channels of the multifunctional passive device, which integrates an antenna array and a multi-channel filter, as described in an embodiment of the present invention.

[0039] Figure 16 This is a schematic diagram of the port isolation curve between the filter and the antenna in the integrated antenna array and multi-channel filter according to an embodiment of the present invention.

[0040] The components are: 1. Metal substrate; 2. Pyramidal horn array; 3. Cavity layer; 301. Multifunctional cavity; 302. External cavity; 303. Capacitor stub; 304. First coupling window structure; 305. Second coupling window structure; 306. Tuning metal pillar; 307. First electromagnetic bandgap structure; 308. Second electromagnetic bandgap structure; 309. Coupled metal ridge; 401. First vertical waveguide section; 402. Second vertical waveguide section; 5. H-type waveguide power divider feed network; 6. High-frequency antenna array feed port; 7. Low-frequency filter feed port. Detailed Implementation

[0041] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0042] It will be understood by those skilled in the art that, unless otherwise defined, all terms used herein (including technical and scientific terms) have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0043] It should also be understood that terms such as those defined in general dictionaries should be understood to have meanings consistent with their meanings in the context of the prior art, and should not be interpreted in an idealized or overly formal sense unless defined as here.

[0044] Those skilled in the art will understand that, unless specifically stated otherwise, the singular forms “a,” “an,” “the,” and “the” used herein may also include the plural forms. It should be further understood that the term “comprising” as used in this specification means the presence of the stated features, integers, steps, operations, elements, and / or components, but does not exclude the presence or addition of one or more other features, integers, steps, operations, elements, and / or groups thereof.

[0045] In the description of this specification, references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of those different embodiments or examples.

[0046] In the description of this specification, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0047] In the description of this specification, the terms “center,” “upper,” “lower,” “front,” “rear,” “left,” “right,” “vertical,” “horizontal,” “top,” “bottom,” “inner,” and “outer,” etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this technology and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this technology.

[0048] Unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," and "setting" should be interpreted broadly. For example, they can refer to a fixed connection or setting, a detachable connection or setting, or an integral connection or setting. Those skilled in the art can understand the specific meaning of these terms in this art according to the specific circumstances.

[0049] To facilitate understanding of the present invention, the present invention will be further explained and described below with reference to the accompanying drawings and specific embodiments. However, the specific embodiments do not constitute a limitation on the embodiments of the present invention.

[0050] Those skilled in the art should understand that the accompanying drawings are merely schematic diagrams of embodiments, and the components in the drawings are not necessarily essential for implementing the present invention.

[0051] This invention provides a multifunctional passive device integrating an antenna array and a multi-channel filter, comprising a metal substrate, a high-frequency antenna array feed port and a low-frequency filter feed port outside the metal substrate. The internal structure of the metal substrate, from top to bottom, consists of a pyramidal horn array, a first vertical waveguide segment, a cavity layer, a second vertical waveguide segment, and an H-type waveguide power divider feed network. The cavity layer includes a multifunctional cavity, an external cavity, capacitor stubs, a first coupling window structure, and a second coupling window structure. A first electromagnetic bandgap structure is loaded within the multifunctional cavity; a second electromagnetic bandgap structure is loaded within the second coupling window structure; a coupling metal ridge is loaded within the first coupling window structure; a tuning metal pillar is loaded on the top of the external cavity; the low-frequency filter port is connected to the external cavity, while the high-frequency antenna array feed port is located at the input waveguide port of the H-type waveguide power divider feed network.

[0052] In one specific embodiment, the multifunctional passive device integrating an antenna array and a multi-channel filter uses a pyramidal horn as a radiator in the antenna array. Each pyramidal horn is connected to a first vertical waveguide segment, and every four first vertical waveguide segments are connected to the top of a multifunctional cavity. The bottom of each multifunctional cavity is connected to a second vertical waveguide segment.

[0053] In one specific embodiment, the multifunctional cavity of the multifunctional passive device integrating the antenna array and multi-channel filter operates as a one-to-four cavity power divider in the antenna array. The electromagnetic signal is input from the feed port of the high-frequency antenna array, and is transmitted sequentially through the H-type power divider feed network and the second vertical waveguide section to the multifunctional cavity, and is equally distributed to the four first vertical waveguide sections to feed the diagonal pyramid horns.

[0054] In one specific embodiment, a filter multiplexing cavity layer of a multifunctional passive device integrating an antenna array and a multi-channel filter achieves multi-channel integration. The multifunctional cavity functions as a cavity resonator, while the external cavity functions as the input and output cavities. The cavities are cascaded through a first coupling structure or a second coupling structure, and various forms of multi-filter channel integrated architectures are formed through different topological combinations.

[0055] In one specific embodiment, the first or second coupling structure of the filter in the multifunctional passive device integrating the antenna array and multi-channel filter changes the coupling strength by adjusting the coupling window size and the height of the coupling metal ridge. The external cavity changes the resonant frequency by adjusting the tuning metal pillar.

[0056] like Figure 1 , Figure 2As shown, specifically, the multifunctional passive device integrating an antenna array and a multi-channel filter provided in this embodiment includes a metal substrate 1, a high-frequency antenna array feed port 6 disposed outside the metal substrate, and a low-frequency filter feed port 7.

[0057] like Figure 3 , Figure 4 As shown, the internal structure of the metal substrate 1, from top to bottom, consists of a pyramidal horn array 2, a first vertical waveguide section 401, a cavity layer 3, a second vertical waveguide section 402, and an H-type waveguide power divider feed network 5. The low-frequency filter port 7 is connected to the cavity layer 3, while the high-frequency antenna array feed port 6 is located at the input port of the H-type waveguide power divider feed network 5.

[0058] like Figure 5 As shown, cavity layer 3 is composed of the multifunctional cavity 301 proposed in this invention, an outer cavity 302, a capacitor branch 303 disposed above the edge of the outer cavity, and a first coupling window structure 304 and a second coupling window structure 305 connecting the multifunctional cavities and the outer cavity. The first coupling window structure 304 is located at both ends of the narrow side of the multifunctional cavity 301, while the second coupling window structure 305 is located on both sides of the wide side of the multifunctional cavity 301.

[0059] like Figure 6 As shown, at both ends of the narrow side of each multifunctional cavity 301, three metal pillars loaded on the bottom are arranged in a triangular pattern, with a certain air gap between each metal pillar and the top of the cavity. Therefore, the metal pillars at the bottom and the top of the cavity together constitute the first electromagnetic bandgap structure 307. The bottom of the second coupling window structure 305 is periodically loaded with three rows of metal pillars, which have a certain air gap with the top of the second coupling window structure. Therefore, the three rows of metal pillars at the bottom and the top of the second coupling window structure together constitute the second electromagnetic bandgap structure 308. In addition, each external cavity 302 has a tuning metal pillar 306 loaded on its top.

[0060] like Figure 7 As shown, two coupling window structures are designed for the integrated multi-channel filter in this embodiment: a first coupling window structure 304 and a second coupling window structure 305. The first coupling window structure 304 has a coupling metal ridge 309 loaded, while the second coupling window structure 305 has a second electromagnetic bandgap structure 308 loaded. When designing the filter, the length of the coupling window (l) is adjusted... type1 l type2 ) and the height of the coupled metal ridge (h) ridge This is used to adjust the coupling strength between the cavities.

[0061] like Figure 8The diagram illustrates the design method for integrating an antenna array and a multi-channel filter in this embodiment of a multifunctional passive device. Each filter's main structure is cascaded via a multifunctional cavity 301, with external cavities 302 serving as both input and output cavities. The cavities are connected horizontally and vertically via a first coupling window structure 304 and a second coupling window structure 305. With a fixed-size multifunctional cavity array, multi-channel filters can be integrated, with each filter channel corresponding to a different topology, thus providing various antenna array and filter integration architectures.

[0062] The multifunctional passive device integrating an antenna array and a multi-channel filter described in this embodiment employs an 8×8 horn antenna array for radiation. Each subarray adopts a 2×2 array size, consisting of four pyramidal horn radiators, four first vertical waveguide sections 401, one multifunctional cavity 301, and one second vertical waveguide section 402. Electromagnetic waves are input through the high-frequency antenna array feed port 6, transmitted to each subarray via the H-type power divider feed network 5, thus collectively achieving electromagnetic wave radiation. Therefore, the multifunctional cavity 301 acts as a one-to-four cavity power divider in the antenna array. The second vertical waveguide section 402 inputs electromagnetic waves, and the four first vertical waveguide sections 401 output four electromagnetic waves of equal power, which are then transmitted to each pyramidal horn radiator. During this process, the multifunctional cavity operates in TE mode. 120 Since the stopband range of the electromagnetic bandgap structure covers the operating frequency band of the high-frequency antenna array, in cavity layer 3, the first electromagnetic bandgap structure 307 in the multifunctional cavity 301 and the second electromagnetic bandgap structure 308 between the cavity can effectively block the input electromagnetic signal from leaking to the adjacent multifunctional cavity 301 and the external cavity 302 through the coupling window structure, thereby achieving isolation between sub-arrays and ensuring high isolation with the filter.

[0063] The multifunctional passive device integrating an antenna array and a multi-channel filter described in this embodiment achieves its filtering function by integrating a low-frequency multi-channel filter through the multiplexed cavity layer 3. Since the electromagnetic bandgap structure operates within the low-frequency passband, the first electromagnetic bandgap structure 307 in the multifunctional cavity 301 is equivalent to a slow-wave loading structure, which allows the TE of the multifunctional cavity to... 110As the mode resonant frequency decreases, electromagnetic waves can couple with adjacent multifunctional cavities through this structural region. The coupling strength can be adjusted by modifying the first coupling window structure 304. Similarly, for the second coupling window structures 305 on both sides of the wide side of the multifunctional cavity, the loaded second electromagnetic bandgap structure 308 is equivalent to a slow-wave loaded structure, enhancing the coupling strength by increasing the capacitance effect compared to the unloaded case. Furthermore, electromagnetic waves can also couple with adjacent cavities through this region. The resonant frequency of the external cavity can be adjusted by loading a tuning metal pillar 306 at the top, while the capacitive stubs 303 on the edge of the external cavity help improve the out-of-band rejection capability of the filter. In the design of this invention, to verify the effectiveness of the integration scheme, a 6th-order linear topology and a 10th-order U-shaped topology integration architecture were adopted. The 6th-order filter channel includes two external cavities 302 and four multifunctional cavities 301, all of which are cascaded through a second coupling window structure 305; the 10th-order filter channel includes two external cavities 302 and eight multifunctional cavities 301, which are cascaded together using a first coupling window structure 304 and a second coupling window structure 305.

[0064] The radiation performance test and simulation results of the multifunctional passive device integrating antenna array and multi-channel filter described in this embodiment in the millimeter-wave band are as follows: Figures 9 to 12 As shown, the -10 dB impedance bandwidth covers 25.2 ~ 34.9 GHz, with in-band gain ripple of less than 3 dB and a maximum radiated gain of up to 29.3 dBi. The tested radiation pattern at 30 GHz is basically consistent with the simulation, exhibiting stable high-gain directional beam radiation characteristics. Thanks to the stopband characteristics of the electromagnetic bandgap structure, the isolation between the antenna array port and the filter port in the millimeter-wave band is greater than 53 dB.

[0065] The filtering performance test and simulation results of the multifunctional passive device integrating antenna array and multi-channel filter described in this embodiment in the microwave frequency band are as follows: Figures 13 to 16 As shown, the -3 dB insertion loss relative bandwidth of the 6th-order filter and the 10th-order filter are 4.8% and 7.7%, respectively, with insertion losses of 1 dB and 1.4 dB at the center frequencies of 11.45 GHz and 11.75 GHz, respectively. The port isolation between the 6th-order and 10th-order filters is greater than 51 dB. Furthermore, due to the inherent low-frequency cutoff characteristics of the high-frequency waveguide ports of the antenna array, the isolation between the antenna array and the filter in the microwave band is greater than 74 dB.

[0066] In summary, this invention successfully integrates a horn array antenna with a multi-channel cavity filter by utilizing the frequency selectivity of an electromagnetic bandgap structure. This invention offers significant advantages such as compact structure, high isolation, and multi-filter channel integration, making it a powerful technical solution for achieving high integration, multifunctionality, and expanded application scenarios in future wireless communication systems.

[0067] While the specific embodiments of the present invention have been described above in conjunction with the accompanying drawings, this is not intended to limit the scope of protection of the present invention. Those skilled in the art should understand that, based on the technical solutions disclosed in the present invention, various modifications or variations that can be made by those skilled in the art without creative effort should be included within the scope of protection of the present invention.

Claims

1. A multifunctional passive device integrating an antenna array and a multi-channel filter, characterized in that, include: A metal substrate, with a high-frequency antenna array feed port and a low-frequency filter feed port disposed outside the metal substrate; The internal structure of the metal substrate, from top to bottom, consists of a pyramidal horn array, a first vertical waveguide segment, a cavity layer, a second vertical waveguide segment, and an H-type waveguide power divider feed network. The low-frequency filter port is connected to the cavity layer, and the high-frequency antenna array feed port is located at the input port of the H-type waveguide power divider feed network.

2. The multifunctional passive device integrating an antenna array and a multi-channel filter according to claim 1, characterized in that, The cavity layer includes a multifunctional cavity, an outer cavity, a capacitor branch disposed above the edge of the outer cavity, a first coupling window structure and a second coupling window structure connecting the multifunctional cavities and the multifunctional cavity and the outer cavity; The first coupling window structure is located at both ends of the narrow side of the multifunctional cavity, and the second coupling window structure is located on both sides of the wide side of the multifunctional cavity.

3. The multifunctional passive device integrating an antenna array and a multi-channel filter according to claim 2, characterized in that, At both ends of the narrow side of each multifunctional cavity, three metal pillars loaded on the bottom are arranged in a triangle, with a certain air gap between each metal pillar and the top of the cavity; the bottom metal pillars and the top of the cavity together constitute the first electromagnetic bandgap structure.

4. The multifunctional passive device integrating an antenna array and a multi-channel filter according to claim 3, characterized in that, The bottom of the second coupling window structure is periodically loaded with three rows of metal pillars. There is a certain air gap between these metal pillars and the top of the second coupling window structure. The three rows of metal pillars and the top of the second coupling window structure together constitute the second electromagnetic bandgap structure. Each external cavity is loaded with a tuning metal pillar on top.

5. The multifunctional passive device integrating an antenna array and a multi-channel filter according to claim 4, characterized in that, The first coupling window structure is loaded with a coupling metal ridge, while the second coupling window structure is loaded with a second electromagnetic bandgap structure. The coupling strength between the cavities is adjusted by adjusting the length of the coupling window and the height of the coupling metal ridge in the filter.

6. The multifunctional passive device integrating an antenna array and a multi-channel filter according to claim 5, characterized in that, Each filter's main structure is cascaded through multifunctional cavities, with the external cavities serving as input and output cavities respectively; between the cavities, a first coupling window structure and a second coupling window structure are used in the horizontal and vertical directions.

7. The multifunctional passive device integrating an antenna array and a multi-channel filter according to claim 6, characterized in that, An 8×8 array of horn antennas is used; each subarray is a 2×2 array, consisting of 4 pyramidal horn radiators, 4 first vertical waveguide sections, 1 multifunctional cavity, and 1 second vertical waveguide section; electromagnetic waves are input from the high-frequency antenna array feed port and transmitted to each subarray through an H-type power divider feed network, thus jointly achieving electromagnetic wave radiation.

8. The multifunctional passive device integrating an antenna array and a multi-channel filter according to claim 6, characterized in that, The filtering function achieves low-frequency multi-channel filter integration through multiplexing cavity layers. In the multifunctional cavity, the first electromagnetic bandgap structure is equivalent to a slow-wave loading structure.

9. The multifunctional passive device integrating an antenna array and a multi-channel filter according to claim 8, characterized in that, For the second coupling window structure on both sides of the wide side of the multifunctional cavity, the second electromagnetic bandgap structure loaded thereon is equivalent to a slow wave loading structure, which enhances the coupling strength by increasing the capacitance effect.

10. The multifunctional passive device integrating an antenna array and a multi-channel filter according to claim 9, characterized in that, The resonant frequency of the external cavity is adjusted by loading a tuning metal pillar at the top, while the capacitive stubs on the edge of the external cavity improve the out-of-band rejection capability of the filter.

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