Planar integrated hollow rectangular dielectric waveguide

Abstract

The invention discloses a planar integrated hollow rectangular dielectric waveguide, and relates to the field of planar integrated waveguides, and the planar integrated hollow rectangular dielectric waveguide comprises an upper dielectric layer, a middle dielectric layer and a lower dielectric layer which are distributed from top to bottom, and a metal ground plane attached to the lower surface of the lower dielectric layer. The left side air hole area, the middle wave guide area and the right side air hole area are distributed from left to right; the middle wave guide region is provided with an air slot in the center of the middle dielectric layer to form a hollow wave guide structure; a plurality of columns of air holes penetrating through the upper dielectric layer, the middle dielectric layer and the lower dielectric layer are formed in the left air hole area and the right air hole area, and an air hole array is formed. The planar integrated hollow rectangular dielectric waveguide designed by the application has the advantages of low loss, easy realization of integrated design and planar integration, and simple and stable structure.

Description

Technical Field

[0001] This application relates to the field of planar integrated waveguides, and in particular to a planar integrated hollow rectangular dielectric waveguide. Background Technology

[0002] In existing terahertz dielectric waveguides, discrete solid rectangular dielectric waveguides are simple in structure and easy to fabricate, but they suffer from high dielectric loss, large attenuation constant, and difficulty in direct integration into planar circuit boards. To enhance planar integration capabilities, some studies have constructed air hole arrays on both sides of solid rectangular dielectric waveguides. However, this structure lacks a metal ground plane, resulting in limited planar integration, insufficient mechanical strength, poor heat dissipation, and inability to achieve electromagnetic shielding. To further enhance planar integration capabilities, a metal ground plane is introduced below the aforementioned structure with air hole arrays to form a substrate integrated mirror dielectric waveguide (SIIG). This metal ground plane can share a ground with other circuits, but the SIIG still has a solid waveguide channel, so the problems of high dielectric loss and large attenuation constant persist. Based on the SIIG structure, a substrate integrated nonradiating dielectric waveguide (SINRD) is constructed by introducing a metal plane on the upper surface. Although bidirectional electromagnetic shielding can be achieved, the introduction of the additional metal plane increases conductor loss, resulting in a large attenuation constant. In recent years, a hollow rectangular dielectric waveguide with a multilayer structure has been proposed. By setting air slots in the middle dielectric layer to form discrete hollow dielectric waveguides, it has a small attenuation constant. However, this structure still does not solve the problem of difficulty in achieving planar integration. Summary of the Invention

[0003] The purpose of this application is to provide a planar integrated hollow rectangular dielectric waveguide, which has the advantages of low loss, easy integration and planar design, and simple and stable structure.

[0004] To achieve the above objectives, this application provides the following solution: In a first aspect, this application provides a planar integrated hollow rectangular dielectric waveguide, comprising: The upper dielectric layer 1, the middle dielectric layer 2, and the lower dielectric layer 3 are distributed from top to bottom, and the metal ground plane 4 is attached to the lower surface of the lower dielectric layer 3; the left air hole region 5, the middle waveguide region 6, and the right air hole region 7 are distributed from left to right. The intermediate waveguide region 6 has an air groove 8 at the center of the middle dielectric layer 2, forming a hollow waveguide structure; the left air hole region 5 and the right air hole region 7 have multiple rows of air holes 9 penetrating the upper dielectric layer 1, the middle dielectric layer 2 and the lower dielectric layer 3, forming an air hole array 10.

[0005] Optionally, the upper dielectric layer 1, the middle dielectric layer 2, and the lower dielectric layer 3 may use the same or different dielectric materials.

[0006] Optionally, the width of the air trough 8 is less than or equal to the width of the intermediate waveguide region 6.

[0007] Optionally, the air holes 9 are arranged periodically or non-periodically.

[0008] Optionally, the air hole 9 can be a round hole, an elliptical hole, or a rectangular hole.

[0009] Optionally, the air hole array 10 is used to reduce the local equivalent dielectric constant of the left air hole region 5 and the right air hole region 7 to form a total internal reflection condition in the middle waveguide region 6.

[0010] Optionally, the metal ground plane 4 is used to realize the common ground integration, electromagnetic shielding, mechanical support and heat dissipation of the planar integrated hollow rectangular dielectric waveguide.

[0011] Optionally, the upper dielectric layer 1 and the lower dielectric layer 3 have the same thickness, and the middle dielectric layer 2 has a thickness less than that of the upper dielectric layer 1.

[0012] Optionally, the planar integrated hollow rectangular dielectric waveguide can operate in the millimeter-wave band and the terahertz band.

[0013] Optionally, the planar integrated hollow rectangular dielectric waveguide is manufactured using printed circuit board technology or planar integrated circuit technology.

[0014] According to the specific embodiments provided in this application, the following technical effects are disclosed: This application provides a planar integrated hollow rectangular dielectric waveguide. By creating an air slot 8 at the center of the middle dielectric layer 2 to form a hollow waveguide structure, the losses caused by the dielectric material in traditional solid waveguides are effectively reduced, significantly lowering the attenuation constant. Simultaneously, the air hole array 10 in the left and right air hole regions 5 and 7 reduces the local equivalent dielectric constant, creating a total internal reflection condition in the middle waveguide region 2, ensuring stable electromagnetic wave transmission within the hollow waveguide structure. The metal ground plane 4 on the lower surface of the lower dielectric layer 3 not only achieves common ground integration with other circuits but also provides excellent electromagnetic shielding, preventing external electromagnetic interference, while enhancing the overall mechanical support strength and heat dissipation performance of the waveguide. The dielectric waveguide designed in this application meets the requirements of integrated design and planar integration, exhibiting a simple structure and high stability. Attached Figure Description

[0015] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0016] Figure 1 A three-dimensional structural schematic diagram of a planar integrated hollow rectangular dielectric waveguide provided in an embodiment of this application; Figure 2 A top view of a planar integrated hollow rectangular dielectric waveguide provided in an embodiment of this application; Figure 3 A front view of a planar integrated hollow rectangular dielectric waveguide provided in an embodiment of this application; Figure 4 A planar integrated hollow rectangular dielectric waveguide provided in an embodiment of this application Ey Cross-sectional local electric field distribution diagram of mode 11; Figure 5 A planar integrated hollow rectangular dielectric waveguide provided in an embodiment of this application Ey S in 11 mode 21 and S 11 Line graph; Figure 6 A planar integrated hollow rectangular dielectric waveguide provided in an embodiment of this application Ey A schematic diagram of the attenuation constant in mode 11.

[0017] Figure label: Upper dielectric layer-1, middle dielectric layer-2, lower dielectric layer-3, metal ground plane-4, left air hole region-5, middle waveguide region-6, right air hole region-7, air slot-8, air hole-9, air hole array-10. Detailed Implementation

[0018] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0019] With the rapid development of emerging technologies such as artificial intelligence, autonomous driving, virtual reality, and high-definition video transmission, existing fifth-generation (5G) mobile communication technology is increasingly unable to meet the future communication demands for high transmission rates, high communication capacity, and low signal latency. Future sixth-generation (6G) mobile communication is gradually expanding its operating frequencies to the Asia-Pacific Hertz and even terahertz bands to obtain greater bandwidth. Simultaneously, given the limited physical space resources, the high-density and diverse deployment of terminals urgently requires a highly integrated system architecture. In this frequency band, traditional planar metal transmission lines, such as microstrip lines, striplines, and coplanar waveguides, suffer from severe conductor losses due to the skin effect and metal surface roughness, and also face manufacturing difficulties. Dielectric waveguides, due to their low loss, low cost, and ease of manufacturing, have attracted widespread attention.

[0020] Therefore, the purpose of this application is to provide a planar integrated hollow rectangular dielectric waveguide with the advantages of low loss, easy integration and planar design, and simple and stable structure.

[0021] To make the above-mentioned objectives, features and advantages of this application more apparent and understandable, the application will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0022] like Figures 1-3 As shown, this embodiment provides a planar integrated hollow rectangular dielectric waveguide, comprising: The upper dielectric layer 1, the middle dielectric layer 2, and the lower dielectric layer 3 are distributed from top to bottom, and a metal ground plane 4 is attached to the lower surface of the lower dielectric layer 3; the cross-section of the lower dielectric layer 3 is distributed from left to right as the left air hole region 5, the middle waveguide region 6, and the right air hole region 7. The intermediate waveguide region 6 has an air groove 8 at the center of the middle dielectric layer 2, forming a hollow waveguide structure, which reduces the attenuation constant; the left air hole region 5 and the right air hole region 7 have multiple rows of air holes 9 that penetrate the upper dielectric layer 1, the middle dielectric layer 2 and the lower dielectric layer 3, forming an air hole array 10.

[0023] In some embodiments, the width of the air slot 8 is less than or equal to the width of the intermediate waveguide region 6. If the width of the air slot 8 exceeds the width of the intermediate waveguide region 6, the air slot 8 will extend into the left air hole region 5 or the right air hole region 7, disrupting the integrity of the air hole array 10 and affecting the distribution of the local equivalent dielectric constant. This will prevent the stable formation of total internal reflection conditions and may cause electromagnetic wave leakage. By limiting the width of the air slot 8, it can be ensured that the hollow waveguide structure is effectively surrounded by the air hole arrays 10 on both sides, maintaining the stable constraint of electromagnetic waves within the intermediate waveguide region 6.

[0024] Air holes 9, penetrating the three dielectric layers, are arranged periodically or aperiodically to form an air hole array 10, which serves to reduce the local equivalent dielectric constant. For example... Figure 2 As shown, in this embodiment, the cross-sectional shape of the air hole 9 can be selected as a round hole, an elliptical hole, or a rectangular hole according to actual design requirements.

[0025] When a periodic arrangement is used, the center-to-center distance between adjacent air holes 9 can be set to 1 / 4 to 1 / 2 of the working wavelength. The electromagnetic wave can be effectively constrained by adjusting the equivalent refractive index of the periodic structure. In a non-periodic arrangement, the control accuracy of the local equivalent dielectric constant of the air hole array 10 can be further improved by optimizing the hole spacing and aperture distribution, so as to meet the waveguide requirements of different frequency bands.

[0026] The air hole array 10 introduces air holes 9 with low dielectric constants in the left air hole region 5 and the right air hole region 7, making the local equivalent dielectric constant of these two regions lower than the equivalent dielectric constant of the middle waveguide region 6. This creates a dielectric constant gradient between the middle waveguide region 6 and the left and right air hole regions 5 and 7, satisfying the total internal reflection condition. This ensures that electromagnetic wave energy is concentrated in the air slot 8 of the middle waveguide region 6 for transmission, reducing energy leakage to the two sides.

[0027] The metal ground plane 4 can be made of a highly conductive metal such as copper, aluminum, or gold, and is attached to the lower surface of the underlying dielectric layer 3 through processes such as sputtering, electroplating, or bonding. The metal ground plane 4 not only provides a stable ground reference for the entire waveguide structure, facilitating common ground integration with other planar circuits (such as antennas, filters, mixers, etc.), but also effectively shields against electromagnetic interference from below and blocks downward radiation of electromagnetic waves from within the waveguide, improving the system's electromagnetic compatibility. Simultaneously, as a structural substrate, the metal ground plane 4 enhances the overall mechanical strength of the waveguide, preventing warping or breakage of the multilayer dielectric layers during processing or use. Furthermore, its excellent thermal conductivity allows for rapid dissipation of heat generated during waveguide operation, preventing localized overheating that could negatively impact device performance.

[0028] The upper dielectric layer 1, middle dielectric layer 2, and lower dielectric layer 3 can be made of the same or different dielectric materials, such as polytetrafluoroethylene, ceramic, quartz, or high-frequency copper-clad laminate materials. In this embodiment, RogersRT / duroid5880 is used. Using the same material simplifies the processing technology and reduces material costs; using different materials allows for the selection of dielectrics with matching characteristics according to the functional requirements of each layer. For example, materials with high mechanical strength can be selected for the upper dielectric layer 1 and lower dielectric layer 3 to improve structural stability, while materials with low dielectric loss can be selected for the middle dielectric layer 2 to reduce electromagnetic wave propagation loss in the dielectric. The thickness of the upper dielectric layer 1 and lower dielectric layer 3 is usually set to be equal, and the thickness of the middle dielectric layer 2 is less than the thickness of the upper dielectric layer 1. This design provides a wider single-mode operating bandwidth compared to the case where the thicknesses of the upper dielectric layer 1, middle dielectric layer 2, and lower dielectric layer 3 are the same. Furthermore, the thicknesses of the upper dielectric layer 1, middle dielectric layer 2, and lower dielectric layer 3 can be flexibly adjusted according to the different requirements of the actual application scenario. For example, in scenarios where high signal transmission efficiency is required, the thickness of the upper dielectric layer 1 and the lower dielectric layer 3 can be appropriately reduced to decrease signal transmission loss; when the middle dielectric layer 2 needs to bear more structural support, its thickness can be increased accordingly to enhance overall stability. This multi-dimensional thickness adjustment method allows the structural design to take into account both electromagnetic performance and mechanical strength, thereby flexibly adapting to diverse technical specifications and application scenario requirements.

[0029] The planar integrated hollow rectangular dielectric waveguide operates in the millimeter-wave band (30GHz-300GHz) and the terahertz band (0.3THz-10THz). In these bands, the losses of traditional metal transmission lines increase dramatically. The hollow waveguide structure proposed in this embodiment significantly reduces the attenuation constant by minimizing the interaction between the dielectric and electromagnetic waves. Simulation results show that in the 60GHz band, the attenuation constant of this waveguide can be as low as below 0.1dB / mm, which is superior to the SIIG structure in the same band. Furthermore, this waveguide can be manufactured using mature printed circuit board (PCB) or planar integrated circuit (LTCC, MEMS) processes. Precise processing of multiple dielectric layers and the formation of air holes 9 and air slots 8 are achieved through photolithography, etching, and drilling, making it suitable for large-scale mass production with low manufacturing costs.

[0030] In practical applications, the operating frequency band, mode characteristics, and loss performance of the waveguide can be controlled by adjusting parameters such as the width and height of the air slot 8 and the period, aperture, and arrangement of the air hole array 10 to meet the application requirements of different scenarios. For example, increasing the width of the air slot 8 can improve the single-mode operating bandwidth of the waveguide, decreasing the aperture of the air hole 9 can enhance the confinement of electromagnetic waves, and optimizing the arrangement period of the air hole array 10 can reduce in-band ripple. This planar integrated hollow rectangular dielectric waveguide can be widely used in 6G communication systems, terahertz imaging, millimeter-wave radar, high-speed data transmission, and other fields. As a core signal transmission unit, it provides strong support for the high integration, low loss, and high reliability of the system.

[0031] In this embodiment, taking the printed circuit board process as an example, the upper dielectric layer 1, the middle dielectric layer 2, and the lower dielectric layer 3 are made of RogersRT / duroid5880 material (relative permittivity of 2.2, loss tangent of 0.0009), with a thickness of... h 1= h 3 = 0.254 mm h 2 = 0.127 mm, length L =21.81mm. Metal ground plane 4 is made of copper (conductivity 5.8 × 10⁻⁶). 7 S / m), thickness h 4 = 0.05mm. The width of the intermediate waveguide region is 6. w =1mm, air slot width 8 w 1 = 0.56mm. Air hole 9 is an elliptical hole, semi-major axis. a =0.435mm, semi-short shaft b =0.37mm, with five columns arranged in each of the left air hole area 5 and the right air hole area 7, and the hole spacing is 0.37mm. p =0.22mm, q =0.12mm.

[0032] Figure 4 Demonstrates the planar integration of hollow rectangular dielectric waveguides at 260 GHz. Ey The cross-sectional local electric field distribution of mode 11. In this mode, the electric field is mainly concentrated in the region of the low-loss air slot 8, which is significantly different from the case in the SIIG structure where the electric field is concentrated at the dielectric-metal interface. As can be clearly seen from the figure, the electric field intensity reaches its maximum value in the central region of the air slot 8, and decreases rapidly in the lateral direction (left and right) from the middle waveguide region 6 to the left air hole region 5 and the right air hole region 7. The electric field intensity is close to zero at the edge of the air hole array 10, indicating that the electromagnetic wave energy is effectively confined within the hollow waveguide structure, verifying the effectiveness of the air hole array 10 in reducing the local equivalent dielectric constant to form the total internal reflection condition.

[0033] Figure 5 Planar integrated hollow rectangular dielectric waveguide demonstrated Ey S in 11 mode 21 and S 11 Curve. In the 220–280 GHz range, S 21 Greater than -2.10 dB, less than -1.18 dB, S 11 Less than −19.90dB, demonstrating good transmission performance and impedance matching characteristics.

[0034] Figure 6 Planar integrated hollow rectangular dielectric waveguide demonstrated Ey Attenuation constant for mode 11. Attenuation constant in the 220–280 GHz range. α The values ​​are greater than 0.027 dB / mm, less than 0.037 dB / mm, and have an average value of 0.032 dB / mm, further demonstrating the low-loss advantage of this hollow dielectric waveguide in the millimeter-wave and terahertz frequency bands, laying a solid foundation for its application in high-speed communication and high-sensitivity detection systems.

[0035] In summary, the beneficial effects of this application are: 1) In this application, an air slot 8 is provided in the intermediate waveguide region 6 to form a hollow waveguide structure. Since a portion of the electromagnetic signal can be transmitted in the low-loss air slot 8, compared with solid waveguide structures such as SIIG and SINRD, this application can effectively reduce the attenuation constant of the dielectric waveguide, which is more conducive to realizing low-loss electromagnetic signal transmission in the millimeter wave / terahertz band.

[0036] 2) This application achieves two key effects by opening air hole arrays 10 on both sides of the left air hole region 5 and the right air hole region 7: On the one hand, the air hole array 10 effectively reduces the equivalent dielectric constant of the local dielectric layer, thereby providing the necessary total internal reflection conditions for the middle waveguide region 6; on the other hand, this structure provides space for integrating other functional devices on the dielectric layer, and is easier to achieve integrated design and planar integration compared to discrete dielectric waveguides.

[0037] 3) This application introduces a metallic ground plane 4, which, compared with discrete hollow dielectric waveguides, significantly improves mechanical strength, stability and heat dissipation performance on the basis of common ground integration, and also provides electromagnetic shielding to suppress external radiation and external interference, thus laying the foundation for the system to achieve high-density and high-reliability planar integration.

[0038] The planar integrated hollow rectangular dielectric waveguide designed in this application can also operate in other modes, such as... Ex Mode 11 or other higher-order modes, etc., are not limited to the provided embodiments.

[0039] In the description of this application, it should be understood that the terms "upper", "middle", "lower", "bottom", "left", "right", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application 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 application.

[0040] This document uses specific examples to illustrate the principles and implementation methods of this application. The descriptions of the above embodiments are only for the purpose of helping to understand the core ideas of this application. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the ideas of this application. In summary, the content of this specification should not be construed as a limitation of this application.

Claims

1. A planar integrated hollow rectangular dielectric waveguide, characterized in that, include: The upper dielectric layer (1), middle dielectric layer (2), and lower dielectric layer (3) are distributed from top to bottom, and a metal ground plane (4) is attached to the lower surface of the lower dielectric layer (3); the left air hole region (5), the middle waveguide region (6), and the right air hole region (7) are distributed from left to right. The intermediate waveguide region (6) has an air groove (8) at the center of the middle dielectric layer (2) to form a hollow waveguide structure; the left air hole region (5) and the right air hole region (7) have multiple rows of air holes (9) that penetrate the upper dielectric layer (1), the middle dielectric layer (2) and the lower dielectric layer (3) to form an air hole array (10).

2. The planar integrated hollow rectangular dielectric waveguide according to claim 1, characterized in that, The upper dielectric layer (1), the middle dielectric layer (2), and the lower dielectric layer (3) may use the same or different dielectric materials.

3. The planar integrated hollow rectangular dielectric waveguide according to claim 1, characterized in that, The width of the air trough (8) is less than or equal to the width of the intermediate waveguide region (6).

4. The planar integrated hollow rectangular dielectric waveguide according to claim 1, characterized in that, The air holes (9) are arranged in a periodic or non-periodic pattern.

5. A planar integrated hollow rectangular dielectric waveguide according to claim 4, characterized in that, The air hole (9) can be a round hole, an elliptical hole, or a rectangular hole.

6. A planar integrated hollow rectangular dielectric waveguide according to claim 1, characterized in that, The air hole array (10) is used to reduce the local equivalent dielectric constant of the left air hole region (5) and the right air hole region (7) to form a total internal reflection condition in the middle waveguide region (6).

7. A planar integrated hollow rectangular dielectric waveguide according to claim 1, characterized in that, The metal ground plane (4) is used to realize the common ground integration, electromagnetic shielding, mechanical support and heat dissipation of the planar integrated hollow rectangular dielectric waveguide.

8. A planar integrated hollow rectangular dielectric waveguide according to claim 1, characterized in that, The upper dielectric layer (1) and the lower dielectric layer (3) have the same thickness, and the middle dielectric layer (2) has a thickness less than that of the upper dielectric layer (1).

9. A planar integrated hollow rectangular dielectric waveguide according to claim 1, characterized in that, The planar integrated hollow rectangular dielectric waveguide operates in the millimeter-wave and terahertz frequency bands.

10. A planar integrated hollow rectangular dielectric waveguide according to claim 1, characterized in that, The planar integrated hollow rectangular dielectric waveguide is manufactured using printed circuit board technology or planar integrated circuit technology.

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