Artificial surface plasmon-based multilayer waveguide device and manufacturing method thereof

Abstract

The invention discloses a multilayer waveguide device based on artificial surface plasmon, which comprises at least three metal layers which are stacked in sequence, and the metal layers are respectively a top metal layer, at least one middle metal layer and a bottom metal layer; at least one middle metal layer in the multi-layer waveguide device is provided with a long thin hole; plasmon structures are arranged on the peripheries of the long and thin holes in one face of at least one layer of the middle metal layer. In the laminated arrangement of the top metal layer, the middle metal layer and the bottom metal layer, the surface of the metal layer adjacent to the surface, provided with the plasmon structure, of the middle metal layer is a flat surface; and the top metal layer or the bottom metal layer is also provided with a waveguide port communicated with the waveguide transmission channel of the plasmon structure. The high-performance and low-cost plasmon-structure high-performance waveguide transmission structure has the advantages of high performance, low cost and good yield.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of microwave engineering and radar communication technology, in particular to a multilayer waveguide device based on surface plasmon polaritons (SSPPs) and a manufacturing method thereof. BACKGROUND

[0002] With the development of radar communication technology and the higher expectations of people for radar communication technology, the antennas in the current mainstream radar system are mostly designed with waveguide structure. However, the machining precision and assembly tolerance of the waveguide antenna will affect its performance, and the current machining process of the main waveguide antenna is mainly computer numerical control (CNC) or plastic surface metallization. However, they have the following disadvantages.

[0003] CNC: This method usually mills the designed structure directly on the metal block. Although its machining precision is high, it has obvious disadvantages: first, the material waste is serious, the metal removal rate is high, resulting in high raw material cost; second, the CNC machining efficiency is low, especially for complex three-dimensional structures, the processing time is amazing, which greatly increases the single piece cost; third, for the structure combined by multiple layers, it is difficult to limit the leakage of electromagnetic signals through welding, especially for high frequency applications.

[0004] Plastic surface metallization: This method first makes a plastic structure substrate through injection molding and other methods, and then deposits a metal film on the plastic surface through chemical plating, electroplating or vacuum evaporation to realize electromagnetic function. This method reduces the raw material cost to a certain extent, but introduces new problems: first, the metallization process steps are complicated, such as the need for activation and sensitization treatment, which is not environmentally friendly, and the adhesion, density and conductivity of the deposited metal layer are often not as good as bulk metal, affecting the final performance of the device, such as increasing the insertion loss; second, the high frequency characteristics of the plastic substrate, such as dielectric constant stability and loss tangent, are usually poor, and there is a problem of thermal expansion coefficient matching, which is not reliable in high power or severe temperature change environment; third, for high frequency applications, if multiple layers are involved, welding process is used, but this will increase the assembly cost and yield.

[0005] Therefore, there is an urgent need in the art for a new structure and manufacturing method that can balance high performance, low cost and good yield. SUMMARY

[0006] In order to solve the technical problems in the above background, the present application proposes a multilayer waveguide device based on surface plasmon polaritons and a manufacturing method thereof.

[0007] To achieve the above technical objectives, the present invention provides a multilayer waveguide device based on artificial surface plasmon resonance (ASPR) comprising at least three metal layers stacked sequentially, wherein the metal layers are a top metal layer, at least one intermediate metal layer, and a bottom metal layer; at least one intermediate metal layer in the multilayer waveguide device is provided with an elongated aperture; a plasmon structure is provided around the elongated aperture on one side of at least one intermediate metal layer; in the stacked arrangement of the top metal layer, intermediate metal layer, and bottom metal layer, the surfaces of the metal layers adjacent to the side of the intermediate metal layer where the plasmon structure is provided are flat surfaces; a waveguide port connected to the plasmon structure is also provided on the top metal layer or the bottom metal layer.

[0008] Optionally, at least one of the top metal layer and the bottom metal layer has a long, narrow groove on the side that connects to the intermediate metal layer. The long, narrow holes and the long, narrow grooves are vertically projected and overlap, and the long, narrow holes and the long, narrow grooves are connected.

[0009] Optionally, a plasmonic structure is provided around the long, thin groove on one side of the intermediate metal layer connecting the bottom metal layer and / or the top metal layer.

[0010] Optionally, the plasmonic structure includes a groove surrounding a long, narrow hole or groove on the surface of the metal layer, a step located within the groove and along the edge of the long, narrow hole or groove, and comb-like protrusions extending outward from the step.

[0011] Optionally, the protrusion is periodically or non-periodically arranged in the groove with period P and electrically connected to the groove. The protrusion is also electrically connected to the step and is arranged at the same height as the step. The step and the protrusion are arranged in a comb-like shape in the groove, and the lateral width of the protrusion is the same.

[0012] Optionally, the shape of the protrusion can be any of the following: rectangle, triangle, semicircle, trapezoid, semi-ellipse, pentagon, or any other polygon with more than five sides.

[0013] Optionally, the dimensions of the protrusion are as follows: the vertical height difference between the protrusion and the groove is between λ / 30 and λ / 20; the distance from one end of the protrusion to the electrical connection step is generally between λ / 10 and λ / 2; the spacing between adjacent protrusions is between λ / 5 and λ / 2, where λ is the wavelength in free space of the electromagnetic wave operating frequency used for transmission.

[0014] Optionally, the two ends of the elongated orifice or groove are further provided with branch one and branch two extending into the orifice or groove.

[0015] Optionally, there is a top metal layer, an intermediate metal layer, and a bottom metal layer; long, thin grooves and plasmon structures are provided in the front of the top metal layer and the bottom metal layer facing the intermediate metal layer, and another flat metal layer is also included, whose front and back are both flat surfaces, and the flat metal layer is connected to the plasmon side of the intermediate metal layer.

[0016] Optionally, the waveguide opening is a wave leakage slit, and the vertical projection of the wave leakage slit is located within the elongated aperture and the elongated groove.

[0017] Optionally, the leaky wave slots are staggered along the centerline of the horizontal waveguide channel's transmission direction.

[0018] Optionally, at least one long slot is provided on each side of the leaky slot and on the outside of the horizontal waveguide channel.

[0019] Optionally, the bottom metal layer is a metal layer formed by metallizing the surface of the printed circuit board.

[0020] Optionally, a waveguide vertical transition structure is provided below the waveguide port on the back side of the bottom metal layer. The waveguide vertical transition structure has a vertical waveguide port that penetrates the waveguide port inside, and the shape of the vertical waveguide port is consistent with the shape of the waveguide port on the bottom metal layer. A plasmonic structure is provided around the periphery of the transition structure.

[0021] Optionally, each set of vertically projected overlapping elongated apertures, elongated slots, and surrounding plasmonic structures constitutes a single-channel slot antenna, including an array antenna composed of multiple arrayed single-channel slot antennas.

[0022] Optionally, an elongated fine hole is provided on the front side of the bottom metal layer, the elongated fine hole being L-shaped, and a plasmonic structure is provided on the front or back side of the intermediate metal layer, with both the bottom and top metal layers having flat surfaces.

[0023] Optionally, elongated fine holes are provided on the front and back sides of the bottom metal layer, and plasmonic structures are provided on both the front and back sides of the intermediate metal layer. The surfaces of the bottom metal layer and the top metal layer are both flat surfaces.

[0024] Furthermore, the present invention also provides a method for manufacturing a multilayer waveguide device based on artificial surface plasmon resonance, comprising the steps of: forming plasmon structures, long fine holes, long fine grooves and waveguide openings on each of the three metal layers by stamping, etching or chemical electroplating; aligning and stacking the processed metal layers, and then performing mechanical and electrical connections.

[0025] Compared with the prior art, the present invention has the following advantages: 1. Significantly reduced costs: It abandons the high-cost CNC integral cutting and complex plastic metallization process, and adopts standard sheet metal and mature flat plate processing technology, such as stamping, etching and chemical electroplating. The material utilization rate is high and it is easy to achieve mass production.

[0026] 2. Excellent and reliable performance: It is made entirely of metals, such as copper and aluminum, which avoids problems with dielectric loss and coating adhesion. It has good conductivity, low high-frequency loss, and stable and reliable performance.

[0027] 3. Flexible design and high integration: The multi-layer stacked structure design and ultra-thin design, with an overall thickness of approximately λ / 5, can easily achieve complex functions. The vertical waveguide port design facilitates integration with other parts of the system.

[0028] 4. Robust structure and reliable connection: The connection points formed by ultrasonic welding, riveting and other assembly methods have high mechanical strength and good electrical performance, which are far superior to adhesive bonding and other methods, and can meet the vibration and reliability requirements of harsh environments such as vehicle-mounted vehicles.

[0029] 5. Versatile Functions: The same basic structure can be easily modified, such as by closing the port or adding a gap, to achieve the function of converting from a transmission line to an antenna, making it widely applicable.

[0030] 6. The multilayer waveguide device of the present invention is mainly used in the millimeter wave region, such as 30GHz-300GHz, but the present invention also has advantages in frequencies above 300GHz or below 30GHz. Attached Figure Description

[0031] For better illustration, the present invention can be further described by way of the non-limiting embodiments given in the accompanying drawings; Figure 1 This is a schematic diagram of the overall structure of a multilayer waveguide device according to an embodiment of the present invention; Figure 2 yes Figure 1 A schematic diagram of a vertical cross-section of one embodiment; Figure 3 yes Figure 1 A side view of one embodiment; Figure 4 This is a schematic diagram of a transversely equidistant cross-sectional structure in one embodiment of the present invention; Figure 5 This is a schematic diagram of the transversely equidistant cross-section of an intermediate layer in one embodiment of the present invention; Figure 6 yes Figure 5 A schematic diagram of the structure from a mid-view perspective; Figure 7 This is a schematic diagram of the transversely equidistant cross-sectional structure of the bottom metal layer in one embodiment; Figure 8This is a schematic diagram of the transversely equidistant cross-sectional structure in the second embodiment of the present invention; Figure 9 yes Figure 8 A schematic diagram of the transverse equidistant cross-sectional structure of the metal layer without plasmon structure in the second embodiment; Figure 10 This is a top view of the third embodiment of the present invention, designed as a single-channel slot antenna; Figure 11 This is a top view of the fourth embodiment of the present invention, designed as a single-channel slot antenna; Figure 12 This is a top view of the fourth embodiment of the present invention, designed as a single-channel slot antenna; Figure 13 This is a bottom view of the fourth embodiment of the present invention, designed as a single-channel slot antenna. Figure 14 This is a top view of the fifth and sixth embodiments of the present invention designed as a single-channel slot antenna; Figure 15 This is a schematic diagram of the overall structure of the sixth embodiment of the present invention, which is designed as a multi-channel slot array antenna.

[0032] To facilitate a better understanding of this invention, the terms used herein are labeled with numbers as follows: 1-Top metal layer, 1a-First intermediate metal layer, 2a-Second intermediate metal layer, 2-Bottom metal layer, 3-Input waveguide port, output waveguide port, 4-5-Intermediate metal layer with elongated narrow holes, 6-Elongated narrow groove, 7-Step, 8-Groove, 9-Protrusion, 10-Branch 1, 13-Long gap, 14-Leakage gap, 15-Waveguide vertical transition structure, 16-PCB, 100-Multilayer waveguide device, 101-Front side, 102-Back side, 110-Plasma structure Detailed Implementation Currently, waveguide devices used in the millimeter-wave band are mainly manufactured using computer numerical control (CNC) or plastic surface metallization, but these methods suffer from drawbacks such as high cost, low yield, and large assembly tolerance redundancy. Therefore, to fundamentally address these problems in the existing technology, this invention provides a multilayer waveguide device based on artificial surface plasmon resonance and its manufacturing method. The invention will be described in detail below with reference to the accompanying drawings and embodiments.

[0033] In the following sections, numerous details are set forth to provide a more thorough explanation of exemplary embodiments. However, it will be apparent to those skilled in the art that embodiments may be practiced without these specific details. In other instances, well-known structures and devices are shown in block diagram or schematic form rather than in detail to avoid obscuring the embodiments. Furthermore, unless specifically noted, features of the different embodiments described below may be combined with each other. Furthermore, in the following description, equivalent or similar reference numerals are used to denote equivalent or similar elements having comparable or similar functions. Since identical or functionally equivalent elements are given the same reference numerals in the drawings, repeated descriptions of elements with the same reference numerals can be omitted. Therefore, the descriptions provided for elements with the same or similar reference numerals are interchangeable. It is understandable that when an element is described as "connected" or "coupled" to another element, it can be directly connected or coupled to the other element or there may be an intermediate element. Conversely, when an element is described as "directly connected" or "directly coupled" to another element, there is no intermediate element. Other terms used to describe the relationship between elements should be interpreted in a similar way (e.g., "between" and "directly between," "adjacent" and "directly adjacent," etc.). In the embodiments described herein or illustrated in the accompanying drawings, any direct electrical connection or coupling (i.e., any connection or coupling without additional intermediate elements) may also be achieved through indirect connection or coupling, i.e., connection or coupling with one or more additional intermediate elements, and vice versa, as long as the general purpose of the connection or coupling is substantially maintained, such as transmitting a particular kind of signal or transmitting a particular kind of information. Features from different embodiments may be combined to form further embodiments. For example, variations or modifications described with respect to one embodiment may also be applicable to other embodiments unless indicated to the contrary.

[0034] As mentioned in the background, traditional waveguide transmission lines utilize hollow patterns on single-layer or multi-layer boards to form waveguide channels. To suppress electromagnetic wave leakage, the hollow patterns are offset, essentially creating an electromagnetic bandgap (EBG) structure. Through periodic or aperiodic pattern offsets, bandgap characteristics are generated on the sidewalls of the waveguide channel, suppressing electromagnetic wave leakage. Therefore, the transmission channel itself is continuous, but the sidewall structure is optimized for leakage suppression rather than directly enhancing transmission. The principle is to create a periodic structure on the waveguide sidewalls through the offset setting of the hollow patterns. This structure generates a bandgap within a specific frequency band, preventing electromagnetic waves from propagating or leaking along the sidewalls. This is similar to the operation of photonic crystal waveguides, where the bandgap effect is used to suppress unwanted radiation. The transmission principle still relies on the electromagnetic wave guidance of the hollow waveguide, but the EBG structure enhances confinement, reducing energy loss. The transmission itself is a continuation of traditional waveguides, but the sidewall design improves performance. Therefore, existing technologies mainly address the leakage problem of traditional waveguides at high frequencies by using offset designs of perforated patterns to form EBG-based sidewall structures. The transmission channel is passively optimized, focusing on suppressing leakage rather than actively guiding transmission.

[0035] The present invention relates to an artificial surface plasmon multilayer waveguide device, comprising at least three metal layers stacked sequentially, wherein the metal layers are a top metal layer, at least one intermediate metal layer, and a bottom metal layer; at least one intermediate metal layer in the multilayer waveguide device is provided with an elongated aperture; a plasmon structure is provided around the elongated aperture on one side of at least one intermediate metal layer; in the stacked arrangement of the top metal layer, intermediate metal layer, and bottom metal layer, the surface of the metal layer connected to the side of the intermediate metal layer with the plasmon structure is a flat surface; a waveguide port connected to the plasmon structure is also provided on the top metal layer or the bottom metal layer.

[0036] Optionally, at least one of the top metal layer and the bottom metal layer has a long, narrow groove on the side that connects to the intermediate metal layer. The long, narrow holes and the long, narrow grooves are vertically projected and overlap, and the long, narrow holes and the long, narrow grooves are connected.

[0037] Optionally, the plasmonic structure includes a groove surrounding a long, narrow hole or groove on the surface of the metal layer, a step located within the groove and along the edge of the long, narrow hole or groove, and comb-like protrusions extending outward from the step.

[0038] The transmission channel of this invention consists of horizontal elongated apertures and horizontal elongated slots, which overlap in vertical projection to form a waveguide path. Crucially, these structures are surrounded by artificial surface plasmon polariton (SSPP) structures, including a first step, a first concave surface, and protrusions. SSPP structures are a type of surface waveguide mechanism capable of exciting and guiding electromagnetic waves to propagate along a metal surface. The transmission channel is defined not only by the apertures and slots but also by the periodic or non-periodic protrusions of the SSPP structure, which confine energy and enable ultrathin waveguide transmission.

[0039] This invention is based on the principle of surface plasmon polaritons (SSPPs). SSPPs are surface electromagnetic modes excited at the metal-air interface, capable of confining electromagnetic waves to propagate within a subwavelength scale. SSPP structures, such as steps, concave surfaces, and protrusions, guide waves along specific paths by controlling surface impedance. The transmission principle is a surface waveguide, rather than a traditional hollow waveguide. SSPPs have advantages such as low loss and strong field confinement, making them particularly suitable for millimeter-wave and terahertz frequency bands. The SSPP structure directly participates in the transmission process, achieving efficient signal guidance from input to output by modulating surface waves. Furthermore, this invention converts the device into an antenna by eliminating the vertical port and adding a leakage slot, further demonstrating its flexibility in transmission functionality. This invention actively guides electromagnetic waves through the SSPP structure; the transmission channel is "actively" designed, utilizing surface waves to achieve efficient transmission. The SSPP structure itself has transmission capabilities while also providing some leakage suppression, but the primary purpose is to construct a compact, low-cost waveguide device.

[0040] The embodiments will be further described below with reference to the accompanying drawings. For ease of description, the side where the top metal layer and the bottom metal layer connect to the intermediate metal layer is the front side, and the side facing away from the intermediate metal layer is the back side. The side where the intermediate metal layer connects to the top metal layer is the front side, and the other side is the back side. The side without plasmon structures is called the flat surface.

[0041] Example 1 In this embodiment, as Figures 1 to 4 As shown, the artificial surface plasmon multilayer waveguide device 100 of the present invention comprises at least three metal layers stacked sequentially, wherein the metal layers are a top metal layer 1, at least one intermediate metal layer, for example, in this embodiment, two intermediate metal layers are included: a first intermediate metal layer 1a, a second intermediate metal layer 2a, and a bottom metal layer 2. In other embodiments, more intermediate metal layers may be included.

[0042] In this embodiment, at least one intermediate metal layer is provided with an elongated aperture 5. Additionally, at least one of the top and bottom metal layers has an elongated slot 6 on its side that connects to the intermediate metal layer. The vertical projections of the elongated aperture 5 and the elongated slot 6 overlap, and the elongated aperture 5 and the elongated slot 6 are connected. The elongated slot serves to form a rectangular waveguide transmission channel with the elongated aperture in the intermediate layer for transmitting electromagnetic signals. The purpose of providing elongated slots in the top or bottom metal layer is to reduce the number of layers and the overall thickness of the structure, thus significantly reducing manufacturing costs. The side of the top and bottom metal layers that connects to the intermediate metal layer is the front side, and the side facing away from the intermediate metal layer is the back side. A plasmonic structure 110 is provided around the elongated aperture 5 on the front side of the intermediate metal layer. The plasmonic structure is used for coupling and efficient transmission of electromagnetic waves, achieving directional radiation or low-loss interconnection of signals. The top metal layer 1 also has two vertical waveguide ports: one as an input waveguide port 3 for electromagnetic signals, and the other as an output waveguide port 4 for signals. Thus, the elongated aperture 5, the elongated slot 6, the top metal layer 1, and the bottom metal layer 2 constitute a waveguide transmission channel, and electromagnetic signals are transmitted through the vertical waveguide port of the top metal layer 1 or the bottom metal layer 2.

[0043] Optionally, in this embodiment, a plasmonic structure 110 is also provided around the elongated groove 6 on the front side of the bottom metal layer. In other embodiments, the elongated groove can also be provided in the bottom metal layer. In the stacked configuration of the top metal layer, intermediate metal layer and bottom metal layer, the side of the intermediate metal layer that connects to the bottom metal layer, top metal layer or other intermediate metal layer with the plasmonic structure is a flat surface.

[0044] In this embodiment, the flat surface of the metal layer of an adjacent layer of the optional multilayer waveguide device is connected to the surface of another metal layer where the plasmonic structure is located.

[0045] In this embodiment, optional, such as Figures 5 to 7 As shown, on the front side 101 of the first intermediate metal layer 1a, protrusions 9 are periodically or non-periodically disposed within the groove 8 with a period P, and are electrically connected to the groove 8. In addition, protrusions 9 are also electrically connected to steps 7, and protrusions 9 and steps 7 are disposed at the same height. Steps 7 and protrusions 9 are disposed in the groove 8 in a comb-like shape. In this embodiment, the lateral width of protrusions 9 is the same as t.

[0046] In this embodiment, the shape of the protrusion 9 can be any one of the following: rectangle, triangle, semicircle, trapezoid, semi-ellipse, pentagon, or any other polygon with more than five sides.

[0047] In this embodiment, optionally, the dimensions of the protrusion 9 are as follows: the vertical height difference between it and the groove 8 is generally between λ / 30 and λ / 20; the distance t from one end of the protrusion 9 to the electrical connection step is generally between λ / 10 and λ / 2; the spacing between adjacent protrusions is generally between λ / 5 and λ / 2, where λ is the wavelength of the electromagnetic wave used for transmission in free space. Dimensions outside the specified range are also within the scope of protection of this invention.

[0048] Optionally, in this embodiment, the top metal layer 1 or the bottom metal layer 2 may also be provided with two vertical waveguide ports 3 and 4. That is, both vertical waveguide ports can be provided on the top metal layer 1 or the bottom metal layer 2, or one vertical waveguide port can be provided on the top metal layer 1 and the other vertical waveguide port can be provided on the bottom metal layer 2. In addition, the two vertical waveguide ports of the top metal layer 1 or the bottom metal layer 2 penetrate through the metal layer. The two vertical waveguide ports of the top metal layer 1 or the bottom metal layer 2, the input waveguide port 3 and the output waveguide port 4, one serves as the input port for electromagnetic signals and the other serves as the output port for signals.

[0049] Optionally, in this embodiment, the two ends of the elongated aperture 5 or elongated slot 6 of the multilayer waveguide device are further provided with a first branch 10 and a second branch (not shown) extending into the aperture or slot. The first branch 10 and the second branch (not shown) can be the same or different. The first branch 10 and the second branch (not shown) generally have the same thickness and width. Furthermore, when the first branch and the second branch extend towards each other in a convex shape, they may or may not be in electrical contact, thus forming a vertically penetrating structure through the elongated aperture 5 or elongated slot 6.

[0050] In this embodiment, the multilayer waveguide device may be a waveguide transmission line.

[0051] Second Embodiment Reference Figure 8 The multilayer waveguide device 100 also comprises at least three stacked metal layers, including a top metal layer 1, a first intermediate metal layer 1a, and a bottom metal layer 2. Long, narrow grooves 6 and plasmon structures are disposed on the front sides of the top metal layer 1 and the bottom metal layer 2 facing the first intermediate metal layer 1a. Plasmon structures are disposed on the back side of the first intermediate metal layer 1a. This embodiment also includes another flat second intermediate metal layer 2a, located between the bottom metal layer and the intermediate metal layers, with both its front and back sides being flat.

[0052] In this embodiment, the surface of the intermediate metal layer containing the exotropic structure must be connected to the flat surface of the adjacent metal layer.

[0053] like Figure 9The two branches 10 and 2 (not shown) extending inward from both ends of the elongated narrow hole 5 are protruding and extend towards each other to form a vertical structural component penetrating the elongated narrow hole 5. In this embodiment, the two branches 10 and 2 (not shown) are rectangular with the same width and thickness.

[0054] Optionally, the branches at both ends of the elongated apertures 5 and elongated grooves 6 in other metal layers can also extend in opposite directions and be electrically connected.

[0055] Optionally, unlike the first and second embodiments, in this embodiment, the waveguide aperture is a long strip-shaped leakage slot, and the vertical projection of the slot is located within the long narrow hole and long narrow groove. Electromagnetic signals are transmitted through the leakage slot of the top metal layer 1 or the bottom metal layer 2. The multilayer waveguide device can also be a waveguide antenna.

[0056] Third Embodiment like Figure 10 In the above-described embodiments, the bottom metal layer is a metal layer formed by metallization on the surface of a printed circuit board (PCB). In this embodiment, the leakage slot 14 inside the PCB 16 is the electromagnetic signal input / output port of the waveguide slot antenna in the entire embodiment. The front side of the PCB 16, the elongated aperture 5, and the top metal layer 1 constitute a horizontal waveguide channel, and multiple leakage slots 14 are opened at the end of the horizontal waveguide on the top metal layer 1. The leakage slots 14 are staggered along the center line of the transmission direction of the horizontal waveguide channel. To achieve a high-performance antenna, at least one elongated slot 13 is provided on both sides of the leakage slot 14 and on the outside of the horizontal waveguide channel. The elongated slot 13 penetrates the top metal layer 1 or at least one intermediate metal layer. In this embodiment, the elongated aperture 5 is L-shaped, and plasmon structures are provided on both the front and back sides of the intermediate metal layer. The surfaces of the bottom metal layer and the top metal layer are both flat surfaces. Fourth embodiment like Figure 11 As shown, the multilayer waveguide device in this embodiment is also a single-channel slot antenna. The multilayer waveguide device includes at least three metal layers, specifically a top metal layer 1, at least one intermediate layer 1a, 2a, and a bottom metal layer 2.

[0057] A long, narrow groove 6 is provided on the back surface 102 of the top metal layer, and long, narrow holes 5 are provided on the intermediate metal layers 1a and 2a. Plasmon structures are arranged around the long, narrow holes 5 and the long, narrow groove 6 on the front surface of the top metal layer 1 and the back surface 102 of the intermediate metal layers, the first intermediate metal layer 1a, and / or the second intermediate metal layer 2a. The bottom metal layer 2 has two flat surfaces. The front surface of the bottom metal layer 2, the long, narrow holes 5, and the top metal layer 1 constitute a horizontal waveguide channel. A leakage slot is formed at the end of the top metal layer 1 at the horizontal waveguide, and the leakage slots are staggered along the centerline of the transmission direction of the horizontal waveguide channel. To achieve a high-performance antenna, at least one long slot is provided on each side of the leakage slot and on the outside of the horizontal waveguide channel. The long slot penetrates the top metal layer or at least one intermediate metal layer.

[0058] like Figure 12 and 13 As shown, preferably, in order to connect the multilayer waveguide device to the PCB, a waveguide vertical transition structure 15 is also provided below the vertical waveguide port 3 on the back side of the bottom metal layer 2. The waveguide vertical transition structure 15 has a through vertical waveguide port inside, and the shape of the vertical waveguide port is consistent with the shape of the vertical waveguide port on the bottom metal layer 2. In addition, a plasmonic structure is provided around the periphery of the transition structure. The purpose is to reduce the impact of the gap generated when the multilayer waveguide device 100 is connected to the PCB 16 on the antenna performance.

[0059] Fifth embodiment As attached Figure 14 The multilayer waveguide device in this embodiment is also a single-channel slot antenna. The multilayer waveguide device includes at least three metal layers, specifically a top metal layer 1, at least one intermediate metal layer, such as a first intermediate metal layer 1a and / or a second intermediate metal layer 2a and a bottom metal layer 2.

[0060] The difference from the fourth embodiment is: First, the plasmon structure is disposed on the front side of the intermediate metal layer and the front side of the bottom metal layer. Second, both sides of the top metal layer are flat. Finally, a long, narrow groove 6 is provided on the front side of the bottom metal layer 2. The remaining design is basically the same as in the fourth embodiment.

[0061] Sixth Embodiment As attached Figure 14 Combining the second, third, and fourth embodiments, the only difference is that the leakage slots 14 in the first three embodiments are arranged to be distributed along the vertical centerline of the horizontal waveguide channel transmission direction. The rest is the same as any of the second, third, and fourth embodiments.

[0062] Seventh Embodiment As attached Figure 15Each set of vertically projected overlapping elongated apertures, elongated slots, and surrounding plasmonic structures constitutes a single-channel slot antenna, including an array antenna composed of multiple arrayed single-channel slot antennas, wherein the implementation of a single-channel slot antenna is any one of the second, third, fourth, and fifth embodiments.

[0063] In addition, the present invention also provides a method for manufacturing the multilayer waveguide device according to the above embodiments, which includes the following steps: forming a plasmonic structure, a long fine hole, a long fine groove and a waveguide opening on each of the three metal layers by stamping, etching or chemical electroplating; aligning and stacking the processed metal layers, and then performing mechanical and electrical connections.

[0064] Specifically, each metal layer (preferably copper or aluminum) is manufactured individually using mature, low-cost, high-precision processes such as stamping, etching, and chemical electroplating, thereby precisely "carving" the required plasmonic structures, long narrow holes / grooves, vertical waveguide ports, and branches on each layer.

[0065] After the processed metal layers are precisely aligned and stacked, a robust mechanical and electrical connection between adjacent metal layers is achieved through one of the following methods: Electrical connections between layers can be achieved through ultrasonic welding, gaps between the connecting surfaces of the layers, screwing, or riveting.

[0066] Each layer features a plasmonic structure, ensuring that assembly between layers does not require welding and preventing electromagnetic energy leakage. This approach not only guarantees performance but also significantly reduces costs and improves assembly tolerances, thus fundamentally solving many problems inherent in existing technologies and processes.

[0067] The multilayer waveguide device described in this invention also has the following significant advantages: Manufacturing costs are lower than traditional CNC machining; The all-metal structure offers improved power capacity compared to plastic metallization processes. It adopts a modular design and can be flexibly configured as a transmission line or antenna as needed.

[0068] By selecting different materials (copper / aluminum) and connection methods, performance and cost requirements can be balanced. While various exemplary embodiments have been disclosed, it will be apparent to those skilled in the art that various changes and modifications can be made to achieve some of the advantages of the concepts disclosed herein without departing from the spirit and scope of the invention. It will be apparent to those skilled in the art that other components performing the same function can be appropriately replaced. It should be understood that other embodiments can be utilized, and structural or logical changes can be made, without departing from the scope of the invention. It should be noted that features interpreted with reference to specific drawings can be combined with features in other drawings, even those not explicitly mentioned. Such modifications to the general inventive concept are intended to be covered by the appended claims and their legal equivalents.

[0069] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the invention. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in the present invention should still be covered by the claims of the present invention.

Claims

1. A multilayer waveguide device based on artificial surface plasmon resonances, characterized in that, The device comprises at least three metal layers stacked sequentially, wherein the metal layers are a top metal layer, at least one intermediate metal layer, and a bottom metal layer; at least one intermediate metal layer in the multilayer waveguide device is provided with an elongated aperture; a plasmonic structure is provided around the elongated aperture on one side of at least one intermediate metal layer; in the stacked arrangement of the top metal layer, intermediate metal layer, and bottom metal layer, the surface of the metal layer adjacent to the side of the intermediate metal layer where the plasmonic structure is provided is a flat surface; a waveguide port connected to the plasmonic structure is also provided on the top metal layer or the bottom metal layer.

2. The multilayer waveguide device based on artificial surface plasmon resonance as described in claim 1, characterized in that, At least one of the top metal layer and the bottom metal layer has a long, narrow groove on the side that connects to the intermediate metal layer. The long, narrow holes and the long, narrow grooves are arranged with their vertical projections overlapping, and the long, narrow holes and the long, narrow grooves are connected.

3. The multilayer waveguide device based on artificial surface plasmon resonance as described in claim 2, characterized in that, A plasmonic structure is provided around the long, narrow groove on one side of the intermediate metal layer connecting the bottom metal layer and / or the top metal layer.

4. The multilayer waveguide device based on artificial surface plasmon resonance as described in claim 3, characterized in that, The plasmonic structure includes a groove surrounding a long, narrow hole or groove on the surface of the metal layer, a step located within the groove and along the edge of the long, narrow hole or groove, and comb-like protrusions extending outward from the step.

5. The multilayer waveguide device based on artificial surface plasmon resonance as described in claim 4, characterized in that, The protrusions are periodically or non-periodically arranged in the groove with period P and are electrically connected to the groove. The protrusions are also electrically connected to the step and are arranged at the same height as the step. The step and the protrusions are arranged in a comb-like shape in the groove and the lateral width of the protrusions is the same.

6. The multilayer waveguide device based on artificial surface plasmon resonance as described in claim 4, characterized in that, The shape of the protrusion can be any of the following: rectangle, triangle, semicircle, trapezoid, semi-ellipse, pentagon, or any other polygon with more than five sides.

7. The multilayer waveguide device based on artificial surface plasmon resonance as described in claim 5, characterized in that, The dimensions of the protrusion are as follows: the vertical height difference between the protrusion and the groove is between λ / 30 and λ / 20; the distance from one end of the protrusion to the electrical connection step is generally between λ / 10 and λ / 2; the spacing between adjacent protrusions is between λ / 5 and λ / 2, where λ is the wavelength in free space of the electromagnetic wave operating frequency used for transmission.

8. The multilayer waveguide device based on artificial surface plasmon resonance as described in claim 4, characterized in that, Both ends of the elongated orifice or groove are provided with branch one and branch two extending into the orifice or groove.

9. The multilayer waveguide device based on artificial surface plasmon resonance as described in claim 4, characterized in that, The structure includes a top metal layer, a middle metal layer, and a bottom metal layer. Long, thin grooves and plasmon structures are provided on the front side of the top and bottom metal layers facing the middle metal layer. It also includes another flat metal layer with flat surfaces on both its front and back sides. This flat metal layer is connected to the plasmon side of the middle metal layer.

10. The multilayer waveguide device based on artificial surface plasmon resonance as described in claim 4, characterized in that, The waveguide opening is a wave leakage slit, and the vertical projection of the wave leakage slit is located within the elongated aperture and the elongated slot.

11. The multilayer waveguide device based on artificial surface plasmon resonance as described in claim 10, characterized in that, Leakage slots are staggered along the centerline of the horizontal waveguide channel's propagation direction.

12. The multilayer waveguide device based on artificial surface plasmon resonance as described in claim 11, characterized in that, At least one long slot is provided on each side of the leaky wave slot and on the outside of the horizontal waveguide channel.

13. The multilayer waveguide device based on artificial surface plasmon resonance as described in claim 1, characterized in that, The bottom metal layer is a metal layer formed by metallizing the surface of the printed circuit board.

14. The multilayer waveguide device based on artificial surface plasmon resonance as described in claim 4, characterized in that, A waveguide vertical transition structure is provided below the waveguide port on the back side of the bottom metal layer. A vertical waveguide port that penetrates the waveguide port is provided inside the waveguide vertical transition structure, and the shape of the vertical waveguide port is consistent with the shape of the waveguide port on the bottom metal layer. A plasmonic structure is provided around the periphery of the transition structure.

15. The multilayer waveguide device based on artificial surface plasmon resonance as described in claim 4, characterized in that, Each set of vertically projected overlapping elongated apertures, elongated slots, and surrounding plasmonic structures constitutes a single-channel slot antenna, including an array antenna composed of multiple arrayed single-channel slot antennas.

16. The multilayer waveguide device based on artificial surface plasmon resonance as described in claim 4, characterized in that, Long, narrow holes are formed on the front side of the bottom metal layer. The long, narrow holes are L-shaped. Plasmon structures are formed on the front or back side of the middle metal layer. The surfaces of the bottom metal layer and the top metal layer are both flat surfaces.

17. The multilayer waveguide device based on artificial surface plasmon resonance as described in claim 4, characterized in that, Long, narrow holes are provided on the front and back sides of the bottom metal layer, and plasmonic structures are provided on both the front and back sides of the middle metal layer. The surfaces of the bottom and top metal layers are both flat surfaces.

18. A method for manufacturing a multilayer waveguide device based on artificial surface plasmon resonance as described in claims 1 to 17, characterized in that, The process includes the following steps: plasmonic structures, long fine holes, long fine grooves, and waveguide openings are formed on each of the three metal layers by stamping, etching, or chemical electroplating; the processed metal layers are aligned and stacked, and then mechanically and electrically connected.

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