Multi-band filtering array antenna

Abstract

The invention relates to a multi-band filtering array antenna. Comprising a localized surface plasma and surface wave transmission gate of a single-layer structure, and an antenna patch assembly, the localized surface plasma is a polygon, and a first medium unit is arranged along the side length of the polygon; the number of the surface wave transmission grids corresponds to the number of the first medium units, second medium units are arranged along the single sides of the long edges of the surface wave transmission grids, and the positions of the second medium units are respectively opposite to the positions of the first medium units; the number of the antenna patch assemblies is one less than that of the surface wave transmission grids; the ports of the surface wave transmission gates are extended and then are connected with the antenna patch assemblies, and the ports of the surface wave transmission gates which are not connected with the antenna patch assemblies are used as output ends. The local surface plasma and the surface wave transmission gate are combined to serve as the multi-band filter, then the multi-band filter is connected with the antenna patch assembly to form the multi-band filtering array antenna, and needed multi-band signals can be obtained at the output end.

Description

Technical Field

[0001] The present invention relates to the field of communication technology, and in particular to a multi-band filtering array antenna. Background Art

[0002] With the development of wireless communication technology, the requirements for miniaturization and integration of devices are getting higher and higher. As an advanced wireless communication technology, micro communication network (MCN) plays an important role in many key fields, such as wireless sensing, health monitoring, in vitro communication and navigation. The successful implementation of these applications depends largely on the effective integration of wireless technology in micro devices. In these devices, antennas and filters play a vital role. They are not only responsible for the transmission of wireless signals, but also protect the devices from interference from external signals and ensure that the devices operate normally within the target frequency band.

[0003] In traditional technology, separate antenna and filter designs are usually used, which is difficult to meet the needs of modern applications. To solve this problem, a filter antenna is proposed, which integrates the functions of antenna and filter into a single component.

[0004] At present, there have been large-scale and in-depth studies on filtering antennas at home and abroad. For example, in the field of dual-band filtering antennas, there are antennas that realize compact 5G millimeter wave applications through two repeated square resonators and T-type feeders; there are switchable dual-band filtering antennas and reconfigurable three-polarization filtering antennas realized by T-type wire piles and PIN diodes; there are flexible energy autonomous filtering antennas and wearable dual-band filtering monopole antennas designed for ethanol detection and wireless communication, but most of these designs and studies use multi-layer structures or require complex feeding networks. Summary of the invention

[0005] Based on this, it is necessary to provide a multi-band filtering array antenna with a low profile, single-layer structure and a simple feeding network to address the above technical problems.

[0006] A multi-band filtering array antenna, comprising: a localized surface plasma, a surface wave transmission grating and an antenna patch assembly;

[0007] The localized surface plasmon and the surface wave transmission grating are a single-layer structure;

[0008] The localized surface plasma is a polygon, and the first dielectric unit is arranged along the side length of the polygon;

[0009] The number of the surface wave transmission gratings corresponds to the number of the first dielectric units, and a second dielectric unit is disposed on one side along the long side of the surface wave transmission grating, and each second dielectric unit is located opposite to each first dielectric unit;

[0010] The number of the antenna patch components is one less than the number of the surface wave transmission gratings; the ports of each surface wave transmission grating are extended and connected to each antenna patch component respectively, and the ports of the surface wave transmission gratings that are not connected to the antenna patch components are used as output ends.

[0011] In one embodiment, the first dielectric unit includes a plurality of dielectric sheets; the dielectric sheets are arranged periodically and spaced vertically inwardly along the side length of the polygon to form a comb-shaped first periodic groove.

[0012] In one embodiment, the first periodic grooves include a middle section, a left section and a right section; the periodic grooves of the middle section have the same vertical inward extension height, the periodic grooves of the left section have a vertical inward extension height that gradually increases from the left end to the middle section, and the periodic grooves of the right section have a vertical inward extension height that gradually increases from the right end to the middle section.

[0013] In one embodiment, the periodic grooves of the left section and the periodic grooves of the right section have the same structure and are symmetrically arranged.

[0014] In one embodiment, the second dielectric unit includes a plurality of dielectric sheets; along the long side of the surface wave transmission grating, the dielectric sheets are arranged periodically and spaced vertically inward on one side to form a comb-shaped second periodic groove.

[0015] In one embodiment, the second periodic grooves include a transmission section and a transition section; the periodic grooves of the transmission section have the same vertically inwardly extending height; the periodic grooves of the transition section have a vertically inwardly extending height that is flush with the height of the periodic grooves of the transmission section on the side close to the port, and gradually increases from the port toward the transmission section on the side away from the port.

[0016] In one embodiment, the number of periodic grooves in the transmission segment is greater than or equal to the number of the first periodic grooves.

[0017] In one embodiment, the first periodic grooves and the second periodic grooves have the same width.

[0018] In one embodiment, the LS plasmon is an equilateral triangle.

[0019] In one embodiment, the antenna patch assembly includes a first antenna patch and a dielectric substrate that are stacked, wherein the first antenna patch located at the top is smaller than the dielectric substrate located at the bottom; and a port of the surface wave transmission grating is connected to the first antenna patch.

[0020] Compared with the prior art, the multi-band filter array antenna provided by the present invention has the following effects:

[0021] 1. The multi-band filter array antenna proposed in the present invention breaks through the design concept of traditional multi-layer filter antennas. By designing the localized surface plasma and the surface wave transmission grating as a single-layer structure with a low profile, the structure is compact and can significantly reduce the overall thickness and weight of the antenna. It has high adaptability to antenna integration and application scenarios, and is particularly suitable for devices with high miniaturization and integration requirements.

[0022] 2. The single-layer structure design can reduce the interaction between layers, thereby effectively reducing these parasitic effects and improving the performance stability of the antenna.

[0023] 3. The number of first dielectric units can be flexibly set according to demand, and the corresponding number of second dielectric units can be set. In this way, the frequency band selectivity of the antenna can be improved to form a variety of local surface wave resonant modes, thereby forming a plurality of frequency passbands, and finally obtaining the required multi-frequency signal. In addition, the antenna has a wider operating frequency range and adapts to more communication standards and application requirements.

[0024] 4. The multi-band filter array antenna feeding network proposed in the present invention is simple and can reduce signal loss; it can be more easily integrated with other systems or modules; in addition, it can better achieve matching and avoid reflection loss and standing wave problems caused by poor matching; it not only reduces design and manufacturing costs, but also facilitates later debugging and maintenance. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying creative work.

[0026] Figure 1 A schematic diagram of the structure of a multi-band filter array antenna in one embodiment;

[0027] Figure 2 A schematic diagram of a localized surface plasma structure in one embodiment;

[0028] Figure 3 A schematic diagram of a surface wave transmission grating structure in one embodiment;

[0029] Figure 4 FIG. 1 is a schematic diagram of a simulated electric field distribution of a multi-band filter on an xoy plane in an embodiment; wherein: Figure 4 (a) is a schematic diagram of the simulated electric field distribution at a frequency of 2.45 GHz. Figure 4(b) is a schematic diagram of the simulated electric field distribution at a frequency of 4.45 GHz. Figure 4 (c) is a schematic diagram of the simulated electric field distribution at a frequency of 5 GHz;

[0030] Figure 5 A schematic diagram of simulating S parameters of a multi-band filter in one embodiment;

[0031] Figure 6 It is a schematic diagram of S11 parameter variation obtained by simulation of a single patch antenna component, a multi-band filter array antenna, and a multi-band filter array antenna on a human body in one embodiment;

[0032] Figure 7 A schematic diagram of actual gain obtained by simulation of a single patch antenna assembly, a multi-band filter array antenna, and a multi-band filter array antenna on a human body in one embodiment;

[0033] Figure 8 FIG. 1 is a schematic diagram of a simulated electric field distribution of a multi-band filter array antenna on an xoy plane in an embodiment; wherein: Figure 8 (a) is a schematic diagram of the simulated electric field distribution at a frequency of 2.45 GHz. Figure 8 (b) is a schematic diagram of the simulated electric field distribution at a frequency of 4.45 GHz. Figure 8 (c) is a schematic diagram of the simulated electric field distribution at a frequency of 5 GHz;

[0034] Fig. 9 A schematic diagram of actual S11 parameter changes obtained by measuring a single patch antenna assembly, a multi-band filter array antenna, and a multi-band filter array antenna on a human body in an embodiment;

[0035] Fig.10 Schematic diagram of simulation and measurement radiation of a multi-band filter array antenna in one embodiment; wherein: Fig.10 (a) is at 2.45 GHz frequency, Schematic diagram of simulation and measurement radiation when Fig.10 (b) is a schematic diagram of the simulated and measured radiation at 2.45 GHz frequency and θ = 90°. Fig.10 (c) is at 4.45 GHz frequency, Schematic diagram of simulation and measurement radiation when Fig.10 (d) is a schematic diagram of the simulated and measured radiation at 4.45 GHz frequency and θ = 90°. Fig.10 (e) is at 5 GHz frequency, Schematic diagram of simulation and measurement radiation when Fig.10 (f) is a schematic diagram of the simulated and measured radiation at 5 GHz frequency and θ = 90°;

[0036] Fig.11 It is the actual gain measured for a single patch antenna component and a multi-band filter array antenna in one embodiment.

[0037] Description of reference numerals:

[0038] Localized surface plasma 11, first dielectric unit 111, dielectric sheet 112, first periodic groove 113, middle section 114, left section 115, right section 116, surface wave transmission grating 22, second dielectric unit 221, port 222, second periodic groove 223, transmission section 224, transition section 225, antenna patch assembly 33, first antenna patch 331, dielectric substrate 332.

[0039] The realization of the purpose, functional features and advantages of the present invention will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0040] In order to make the purpose, technical solution 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 used to limit the present invention.

[0041] It should be noted that all directional indications in the embodiments of the present invention (such as up, down, left, right, front, back, etc.) are only used to explain the relative position relationship, movement status, etc. between the components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0042] In addition, in the present invention, descriptions such as "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" or "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0043] In the present invention, unless otherwise clearly specified and limited, the terms "connection", "fixation", etc. should be understood in a broad sense. For example, "fixation" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, an electrical connection, a physical connection, or a wireless communication connection; it can be a direct connection, or an indirect connection through an intermediate medium, or it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0044] The following will describe the implementation of the present invention in detail with reference to the accompanying drawings in the embodiment diagram of the present invention.

[0045] See also Figures 1 to 3 , shows a multi-band filtering array antenna in an embodiment of the present invention, comprising: a localized surface plasmon 11, a surface wave transmission grating 22 and an antenna patch assembly 33. The localized surface plasmon 11 and the surface wave transmission grating 22 are single-layer structures; the localized surface plasmon 11 is a polygon, and a first dielectric unit 111 is arranged along the side length of the polygon; the number of surface wave transmission gratings 22 corresponds to the number of first dielectric units 111, and a second dielectric unit 221 is arranged on one side along the long side of the surface wave transmission grating 22, and each second dielectric unit 221 is respectively opposite to each first dielectric unit 111; the number of antenna patch assemblies 33 is one less than the number of surface wave transmission gratings 22; the ports 222 of each surface wave transmission grating 22 are extended and respectively connected to each antenna patch assembly 33, and the ports 222 of the surface wave transmission grating 22 that are not connected to the antenna patch assembly 33 are used as output ends.

[0046] It can be understood that the filtering antenna can achieve selective transmission of signals of specific frequencies while suppressing unnecessary signals, thereby enhancing the anti-interference ability of the device.

[0047] The present invention combines the localized surface plasma 11 with the surface wave transmission grating 22 to form a multi-band filter, and then connects the multi-band filter to the antenna patch assembly 33 to form a multi-band filter array antenna, which transmits surface waves through the second dielectric unit 221 on the surface wave transmission grating 22. The surface waves occasionally interact with the first dielectric unit 111 on the localized surface plasma 11 to form a variety of localized surface wave resonant modes, thereby forming a plurality of frequency passbands. It can be seen that the number of the first dielectric units 111 can be flexibly set according to the needs, and the second dielectric units 221 are set according to the number of the first dielectric units 111, so as to realize the transmission of the required number of specific frequency signals, and finally obtain the required multi-frequency signals at the output end, and filter out the signals outside the requirements.

[0048] In addition, the present invention breaks through the design thinking of traditional multi-layer filtering antennas. By designing the localized surface plasma and the surface wave transmission grating as a single-layer structure with a low profile, the multi-band filter is also a single-layer structure. Its structure is compact and can significantly reduce the overall thickness and weight of the antenna. It has high adaptability to the integration and application scenarios of the antenna, and is particularly suitable for devices with high requirements for miniaturization and integration, such as wearable devices. Due to its compact design, thin thickness and light weight, it can provide greater design flexibility for wearable devices, so that wearable devices can maintain efficient wireless communication capabilities while being lighter and more comfortable, providing new possibilities for the development of future wearable devices. In addition, the design of the single-layer structure can reduce the interaction between layers, thereby effectively reducing these parasitic effects and improving the performance stability of the antenna.

[0049] It is worth noting that, for ease of understanding, this embodiment Figures 1 to 3 The multi-band filter array antenna shown in is specifically a three-bandpass multi-band filter array antenna. The present invention will specifically illustrate the scheme with a three-bandpass multi-band filter array antenna, but it does not constitute a specific limitation on the multi-band filter array antenna proposed in the present invention. It can also be set to a four-bandpass, five-bandpass, or even more-bandpass filter array structure according to needs. The number of passbands is related to the cutoff frequency of the localized surface plasma unit structure. By designing the localized surface plasma unit structure, the corresponding number of frequency band signals can be obtained. The specific structural principle is the same and will not be elaborated in the following.

[0050] Specifically, see Figure 1 , which is a schematic diagram of the multi-band filter array antenna structure. In order to obtain a three-band signal, the localized surface plasma 11 is set to a triangle, and the first dielectric units 111 are respectively set along the three sides of the triangle; according to the number of the first dielectric units 111, three surface wave transmission gratings 22 are set, and the surface wave transmission grating 22 is a long rectangular structure, and a second dielectric unit 221 is set on one side of the long side of the surface wave transmission grating 22, and the three second dielectric units 221 are respectively opposite to the three first dielectric units 111; the number of antenna patch components 33 is one less than the number of surface wave transmission gratings 22, that is, two antenna patch components 33 are set, and the ports 222 of the two surface wave transmission gratings 22 are extended and connected to the antenna patch components 33 respectively, and the port 222 of the surface wave transmission grating 22 that is not connected to the antenna patch component 33 is used as the output end.

[0051] See also Figure 2, is a schematic diagram of the structure of the localized surface plasma. The localized surface plasma 11 is an equilateral triangle, and the first dielectric unit 111 is respectively arranged on the three long sides of the equilateral triangle. The first dielectric unit 111 includes a plurality of dielectric sheets 112; when arranged, the dielectric sheets 112 are arranged periodically along the length of the triangle side and vertically inward to form a comb-shaped first periodic groove 113. The first periodic groove 113 includes a middle section 114, a left section 115 and a right section 116; the periodic grooves of the middle section 114 extend vertically inward to the same height, the periodic grooves of the left section 115 extend vertically inward to gradually increase from the left end to the middle section 114, and the periodic grooves of the right section 116 extend vertically inward to gradually increase from the right end to the middle section 114. More specifically, the number of periodic grooves of the left section 115 and the number of periodic grooves of the right section 116 are equal and symmetrically arranged.

[0052] It is worth noting that the size of each part of the localized surface plasma 11 can be set. For example, the height of the periodic grooves of the middle section 114, the left section 115 and the right section 116 can be adjusted separately or simultaneously to meet the corresponding frequency band, the number of passbands, the adjustment of the resonance mode, and the impedance matching requirements; the number of dielectric sheets 112 of the middle section 114, the left section 115 and the right section 116 can also be increased or decreased to form different numbers of periodic grooves to meet the corresponding localized resonance mode to surface wave propagation mode conversion requirements. Generally, the periodic grooves of the left section 115 and the right section 116 are of the same structure and symmetrical settings. The three corners of the equilateral triangle can be set to a cross section with a width of t1, and the width of t1 can be adjusted to meet different requirements for adjusting the resonance mode.

[0053] See also Figure 3 , is a schematic diagram of the surface wave transmission grating structure. The surface wave transmission grating 22 is a long rectangular structure, and a second dielectric unit 221 is arranged on one side of the long side. The second dielectric unit 221 also includes a plurality of dielectric sheets 112. When arranged, dielectric sheets 112 are arranged periodically and vertically inwardly on one side along the long side of the surface wave transmission grating 22 to form a comb-shaped second periodic groove 223. The second periodic groove includes a transmission section 224 and a transition section 225; the periodic grooves of the transmission section 224 extend vertically inward to the same height; the periodic grooves of the transition section 225 extend vertically inward to a height that is flush with the periodic groove height of the transmission section 224 on the side close to the port 222, and gradually increases from the port 222 to the transmission section 224 on the side away from the port 222. The number of periodic grooves of the transmission section 224 is greater than or equal to the number of the first periodic grooves 113, so as to match the first periodic grooves 113.

[0054] Furthermore, the dielectric sheets 112 in the first dielectric unit 111 and the second dielectric unit 221 are arranged at equal intervals periodically, so that the widths of the first periodic grooves 113 and the second periodic grooves 223 are the same. When the second dielectric unit 221 is positioned opposite to the first dielectric unit 111, the openings of the first periodic grooves 113 and the openings of the second periodic grooves 223 are positioned opposite to each other, so that when surface wave transmission is performed, the first periodic grooves 113 and the second periodic grooves 223 can interact with each other to excite a resonance mode (i.e., a resonant mode).

[0055] The port 222 is the remaining width W3 on the short side of the long rectangular structure after the second dielectric unit 221 is arranged on the surface wave transmission grating 22. The port 222 with the width W3 is extended and connected to the antenna patch assembly.

[0056] It is worth noting that the dimensions of each part of the surface wave transmission grating 22 can be set, for example, the height of the periodic grooves of the transmission section 224 and the transition section 225 can be adjusted separately or simultaneously to meet the requirements of adjusting different transmission frequencies; the number of dielectric sheets 112 of the transmission section 224 and the transition section 225 can also be increased or decreased to form different numbers of periodic grooves to meet the conversion of local resonance mode and surface wave, and the impedance matching requirements between surface wave transmission and output port. In addition, the width W3 of the port 222 can also be adjusted to meet the corresponding impedance matching requirements. The local surface plasma 11 and the surface wave transmission grating 22 are preferably made of metal material.

[0057] The antenna patch assembly 33 includes a first antenna patch 331 and a dielectric substrate 332 which are stacked, wherein the first antenna patch 331 located at the top is smaller than the dielectric substrate 332 located at the bottom; the port 222 of the surface wave transmission grating 22 is connected to the first antenna patch 331. When connected, a slot with a depth of L4 and a width of W3 is opened on one side of the first antenna patch 331, and the port 222 extends into the slot and connects to the first antenna patch 331. The first antenna patch 331 is a rectangular patch antenna, preferably made of metal material, which has the characteristics of low profile, simple structure, and easy matching with PCMS. Preferably, the dielectric substrate has a dielectric constant of 2.2, a loss angle of 0.0009, a thickness of 1.524 mm, and a metal patch without patterns on the back of the dielectric substrate.

[0058] When in use, the dimensions of each part of the localized surface plasma 11 and the surface wave transmission grid 22 are set according to the frequency signal to be transmitted, and then connected to the antenna patch assembly 33. The antenna patch assembly 33 receives the radiation wave and converts it into a surface wave in the two surface wave transmission grids 22. The surface wave interacts with the three first dielectric units 111 in the triangular localized surface plasma 11 to excite three resonance modes, forming a passband of three frequencies, and finally obtaining a three-frequency signal at the output end. In this way, a three-bandpass multi-band filter array antenna is realized to filter out other interference signals and only obtain the three-frequency signal that needs to be transmitted.

[0059] Similarly, when it is necessary to obtain a quad-frequency signal, the localized surface plasmon 11 can be set to a quadrilateral; when it is necessary to obtain a multi-frequency signal, the localized surface plasmon 11 can be set to a polygon, and then the surface wave transmission grating 22 and the antenna patch assembly 33 can be set accordingly.

[0060] In one of the embodiments, in order to verify the superiority of the multi-band filter array antenna proposed in the present invention, a three-bandpass multi-band filter array antenna structure is still used. The dimensions of each component are designed, and based on the application scenario of the wearable communication system, three frequencies of 2.45 GHz, 4.45 GHz and 5 GHz are transmitted for simulation and experimental measurement.

[0061] First, according to the pre-designed dimensions, a multi-band filter formed by the combination of the localized surface plasma 11 and the surface wave transmission grating 22 is modeled, and then a simulation is performed. The simulated electric field distribution obtained by the simulation is as follows: Figure 4 As shown in the figure, E Z represents the electric field intensity of the xoy plane along the z-axis direction; the results show that this method can effectively excite three artificial localized surface plasmon resonance modes, propagate surface waves, and perform three out-of-band suppression.

[0062] See also Figure 5 , is a schematic diagram of simulated S parameters of a multi-band filter, the multi-band filter is a three-band pass multi-band filter, and it can be found that the three-band pass multi-band filter designed by the present invention has relatively good parameters at three frequency points. Therefore, the three-band pass multi-band filter designed in this embodiment can meet the design requirements of the three-band pass multi-band filter array antenna.

[0063] After the three-bandpass multi-band filter meets the design requirements, a patch antenna assembly is selected, and the three-bandpass multi-band filter is connected to the antenna patch assembly 33 to form a three-bandpass multi-band filter array antenna. Then, a single patch antenna assembly, a three-bandpass multi-band filter array antenna, and a three-bandpass multi-band filter array antenna set on the human body are modeled, and then simulation verification is performed. The S11 parameter changes obtained by simulation are as follows: Figure 6As shown, the simulation results show that there are three frequencies of resonance in the system.

[0064] In addition, the real gain of the multi-band filter array antenna is also a very important parameter. Therefore, in this embodiment, the real gain of three cases, namely, a single patch antenna component, a three-band pass multi-band filter array antenna, and a three-band pass multi-band filter array antenna set on the human body, is simulated in the frequency range of 2 GHz to 5.5 GHz. The simulation results are as follows: Figure 7 As shown in the figure, the results show that the simulated actual gains of the three-bandpass multi-band filter array antenna at the resonant frequencies of 2.45GHz, 4.45GHz and 5GHz are 5.7dBi, 6.27dBi and 8.49dBi respectively. In addition, there are three sharp passbands with values ​​greater than 0dBi in the frequency bands of 2.38GHz to 2.58GHz, 4.3GHz to 4.47GHz and 4.7GHz to 5.3GHz.

[0065] When the three-bandpass multi-band filter array antenna is placed at the plane interface between air and human tissue (εr = 50), the simulated electric field on the xoy plane is as follows: Figure 8 As shown in the figure, E Z represents the electric field intensity in the xoy plane along the z-axis. Our results show that the triple resonant localized surface plasmon modes can be effectively excited, resulting in triple out-of-band suppression.

[0066] When the simulation results of the three-bandpass multi-band filter array antenna meet the requirements, the physical processing is carried out according to the dimensions obtained by the simulation, and a series of experiments and tests are carried out. When carrying out the physical processing, the printed circuit board technology is used, and the multi-band filter array antenna is made of F4B material. The S parameter measurement is designed by vector network analysis, such as Fig. 9 The figure shows the actual S11 parameter variation obtained by measuring a single patch antenna component, a multi-band filter array antenna, and a multi-band filter array antenna on the human body. Compared with a single patch antenna component, the multi-band filter array antenna has good S11<-10dB filtering performance at 2.45GHz, 4.45GHz, and 5GHz. Except for 5GHz, the filter bands in the measurement are Figure 6 The difference is mainly attributed to the higher LSPR mode losses.

[0067] Furthermore, the normalized radiation patterns of the φ = 90° and θ = 90° planes were measured in a dark room. Fig.10 , Fig.10 (a) Fig.10 (b) with Fig.10 (c) shows the schematic diagram of the simulated and measured radiation at 2.45 GHz, 4.45 GHz, and 5 GHz frequencies, respectively. represents the yz plane, and θ represents the xy plane. Although there are certain errors due to additional cable loss, high modal loss, measurement errors, etc., the measured results are basically consistent with the simulation results. They have almost the same number of main lobes and side lobes, and have the same half-power beamwidth in the φ=0° and θ=90° planes. The measurement results show that in the application scenarios of health monitoring and wearable communication systems, the three-bandpass multi-band filter array antenna provides a wide angle coverage for signal transmission. Fig.11 The measured achieved gains of a single patch antenna assembly and a three-bandpass multi-band filter array antenna are shown, which agree well with the simulation results. Compared with the achieved gain of a single patch antenna, the multi-band filter array antenna proposed in the present invention has better out-of-band suppression performance within the desired frequency band.

[0068] In summary, the actual gains of the three-bandpass multi-band filter array antenna in this embodiment at the resonant frequencies of 2.45GHz, 4.45GHz and 5GHz are 5.53dBi, 5.12dBi and 4.95dBi respectively. In addition, there are three sharp passbands with values ​​greater than 0dBi in the frequency bands of 2.38GHz to 2.53GHz, 4.38GHz to 4.5GHz and 4.63GHz to 5.12GHz. The test results show that the design has good filtering performance, with three sharp passbands and high target out-of-band suppression, meeting the requirements for a three-bandpass multi-band filter array antenna.

[0069] The technical features of the above embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0070] The above-mentioned embodiments only express several implementation modes of the present invention, and the description thereof is relatively specific and detailed, but it cannot be understood as limiting the scope of the invention. It should be pointed out that, for a person of ordinary skill in the art, several modifications and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the attached claims.

Claims

1. A multi-band filtering array antenna, characterized in that: include: Localized surface plasmon, surface wave transmission grating and antenna patch components; The localized surface plasmon and the surface wave transmission grating are a single-layer structure; The localized surface plasma is a polygon, and the first dielectric unit is arranged along the side length of the polygon; The number of the surface wave transmission gratings corresponds to the number of the first dielectric units, and a second dielectric unit is disposed on one side along the long side of the surface wave transmission grating, and each second dielectric unit is located opposite to each first dielectric unit; The number of the antenna patch components is one less than the number of the surface wave transmission gratings; the ports of each surface wave transmission grating are extended and connected to each antenna patch component respectively, and the ports of the surface wave transmission gratings that are not connected to the antenna patch components are used as output ends.

2. The multi-band filtering array antenna according to claim 1, characterized in that: The first dielectric unit includes a plurality of dielectric sheets; The dielectric sheets are arranged periodically and spaced vertically inwardly along the side length of the polygon to form first periodic grooves in the shape of comb teeth.

3. The multi-band filtering array antenna according to claim 2, characterized in that: The first periodic groove includes a middle section, a left section and a right section; The periodic grooves of the middle section extend vertically inwardly to the same height, the periodic grooves of the left section extend vertically inwardly to a height that gradually increases from the left end to the middle section, and the periodic grooves of the right section extend vertically inwardly to a height that gradually increases from the right end to the middle section.

4. The multi-band filtering array antenna according to claim 3, characterized in that: The periodic grooves of the left section and the periodic grooves of the right section have the same structure and are symmetrically arranged.

5. The multi-band filtering array antenna according to claim 1, characterized in that: The second dielectric unit includes a plurality of dielectric sheets; The dielectric sheets are arranged along the long side of the surface wave transmission grating at intervals and vertically inward on one side to form a second periodic groove in the shape of comb teeth.

6. The multi-band filtering array antenna according to claim 5, characterized in that: The second periodic groove includes a transmission section and a transition section; The periodic grooves of the transmission section have the same height when extending vertically inward; The vertical inward extension height of the periodic grooves of the transition section is flush with the height of the periodic grooves of the transmission section on the side close to the port, and gradually increases from the port to the transmission section on the side away from the port.

7. The multi-band filtering array antenna according to claim 6, characterized in that: The number of the periodic grooves of the transmission section is greater than or equal to the number of the first periodic grooves.

8. The multi-band filtering array antenna according to any one of claims 2 to 7, characterized in that: The first periodic grooves and the second periodic grooves have the same width.

9. The multi-band filtering array antenna according to claim 1, characterized in that: The localized surface plasmon is an equilateral triangle.

10. The multi-band filtering array antenna according to claim 1, characterized in that: The antenna patch assembly comprises a first antenna patch and a dielectric substrate which are stacked, wherein the first antenna patch located on the upper side is smaller in size than the dielectric substrate located on the lower side; A port of the surface wave transmission grating is connected to the first antenna patch.

Images