An energy transmission window and a manufacturing method thereof

Abstract

Embodiments of the present invention disclose an energy transmission window and a manufacturing method thereof. The energy transmission window includes two dielectric substrates, and an electromagnetic resonance unit clamped and fixed between the two dielectric substrates. The electromagnetic resonance unit includes a plurality of resonance units arranged in an array. The resonance unit includes a first metal ring having a first opening, and a second metal ring having a second opening located inside the first metal ring. The present invention effectively solves the problems of large design difficulty, complex process, high cost, etc. of the existing energy transmission window, and can significantly expand the working bandwidth without increasing the volume of the components of the energy transmission window.

Description

Technical Field

[0001] The present invention relates to the field of microwave vacuum electron technology. More specifically, it relates to an energy transmission window and a manufacturing method thereof. Background Art

[0002] Microwave amplifiers play a key role in multiple fields such as wireless communication, radar systems, satellite communication, and scientific research. Its working bandwidth is closely related to the bandwidth of the energy transmission window. Nowadays, long-range millimeter-wave high-resolution imaging radars require a wider relative bandwidth, which is difficult to achieve for energy transmission windows with traditional structures. Due to the impedance mismatch on both sides of the waveguide, the traditional single-layer energy transmission window can only achieve narrowband transmission. From a design perspective, in order to expand the bandwidth, a structure design with multiple window layers is often adopted. Introducing dielectric materials on both sides of the original waveguide can achieve better matching, as Figure 1 shown.

[0003] However, since the dielectric constant of the material itself is constant, this limits the dielectric matching between multiple layers of windows, making the design of wide-bandwidth energy transmission windows very difficult. From a process perspective, the welding of the multi-layer window structure is complex, with high precision requirements for the spacing between adjacent window pieces, resulting in a low yield rate. Also, the problem of how to exhaust air (maintain a vacuum state) between the window pieces needs to be fully considered. When the device is in a high-power working state, there is a risk of vacuum breakdown.

[0004] For this reason, a broadband energy transmission window with a metasurface structure was subsequently proposed. Its structure is as Figure 2 shown. This type of energy transmission window loads columnar loading units with a periodic structure on both sides of the circular uniform dielectric in the middle. By changing the height of the matching layer (columnar loading units with a periodic structure), the structural dimensions of the columnar loading units (radial size, material, gap between columnar loading single pieces), the matching dielectric constant can be adjusted arbitrarily, thus having a better matching effect to achieve the purpose of expanding the bandwidth. However, this metasurface structure has extremely high precision requirements for the matching layer, is difficult to design, has a high manufacturing cost, and is not conducive to processing and implementation.

[0005] Therefore, it is necessary to break through the bottlenecks in the existing technology such as narrow bandwidth, dependence on the inherent properties of materials, and difficult processing and welding, so as to improve the working performance of vacuum electronic devices and give full play to their advantages in the millimeter-wave and even terahertz frequency bands to a greater extent. Summary of the Invention

[0006] An object of the present invention is to provide an energy transmission window that can effectively expand the working bandwidth of the device while significantly reducing the manufacturing process difficulty of the energy transmission window, and can be flexibly designed according to technical requirements such as the working wavelength, frequency band, and bandwidth of the device.

[0007] Another object of the present invention is to provide a manufacturing method of the energy transmission window as described above.

[0008] To achieve the above object, the present invention adopts the following technical solutions:

[0009] According to the first object of the present invention, the present invention first provides an energy transmission window, which includes two dielectric substrates, and an electromagnetic resonance unit clamped and fixed between the two dielectric substrates;

[0010] The electromagnetic resonance unit includes a plurality of resonant units arranged in an array;

[0011] The resonant unit includes:

[0012] A first metal ring having a first opening, and

[0013] A second metal ring having a second opening located inside the first metal ring.

[0014] In addition, preferably, the first opening and the second opening are arranged in opposite directions.

[0015] In addition, preferably, a first spacing space is included between the ring body of the first metal ring and the ring body of the second metal ring; a second spacing space is included between adjacent two resonant units, and the first metal ring and the second metal ring are concentrically arranged.

[0016] In addition, preferably, the first opening directions of a plurality of first metal rings face the same direction.

[0017] In addition, preferably, the second opening directions of a plurality of second metal rings face the same direction.

[0018] In addition, preferably, a plurality of resonant units are arranged in a regular array in the plane formed by the electromagnetic resonance unit.

[0019] In addition, preferably, the electromagnetic resonance unit includes an intermediate arrangement area and a side arrangement area located at the edge of the intermediate arrangement area;

[0020] The intermediate arrangement area is arranged in a rectangular array, and the side arrangement area is arranged in a gradient array.

[0021] According to the second object of the present invention, the present invention also provides a manufacturing method of an energy transmission window, including the following steps:

[0022] S1. Provide a first dielectric substrate, and set a metal layer on one side surface of the first dielectric substrate, and the metal layer covers the side surface of the first dielectric substrate;

[0023] S2. Through an etching process, the electromagnetic resonance unit is formed on the metal layer;

[0024] S3. Provide a second dielectric substrate, which is fixed to the side of the electromagnetic resonance unit facing away from the first dielectric substrate, to obtain the energy transmission window.

[0025] In addition, a preferred solution is that the electromagnetic resonance unit includes a plurality of resonant units arranged in an array; the resonant unit includes a first metal ring having a first opening and a second metal ring having a second opening located inside the first metal ring.

[0026] In addition, a preferred solution is that the first metal ring and the second metal ring are concentrically arranged.

[0027] The beneficial effects of the present invention are as follows:

[0028] The present invention provides a new energy transmission window structure. This structure forms a resonant unit through the first metal ring and the second metal ring, and uses a plurality of resonant units to form an electromagnetic resonance unit. This design effectively solves the problems of the existing energy transmission window in terms of high design difficulty, complex process, and high cost. The energy transmission window structure can be widely applied to the energy transmission systems of various broadband vacuum electronic devices such as klystrons, traveling wave tubes, and gyro-traveling wave tubes. It can significantly expand the working bandwidth without increasing the volume of the energy transmission window components. Its high design flexibility and application universality contribute to improving the yield rate during mass production. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The following further elaborates on the specific embodiments of the present invention with reference to the accompanying drawings.

[0030] Figure 1 Shows a structure of an existing energy transmission window.

[0031] Figure 2 Shows another structure of an existing energy transmission window.

[0032] Figure 3 Shows the overall structure of the energy transmission window provided by the present invention.

[0033] Figure 4 Shows a schematic diagram of the structure of the resonant unit in the energy transmission window structure provided by the present invention.

[0034] Figure 5 Shows a schematic diagram of the structure of the electromagnetic resonance unit in the energy transmission window structure provided by the present invention.

[0035] Figure 6 Is a result diagram of the reflection coefficient of the electromagnetic simulation software for the energy transmission window provided by the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0036] To more clearly illustrate the present invention, the present invention will be further described below in conjunction with preferred embodiments and the accompanying drawings. Similar components in the drawings are denoted by the same reference numerals. Those skilled in the art should understand that the content specifically described below is illustrative rather than restrictive, and should not be used to limit the protection scope of the present invention.

[0037] To achieve the broadband energy transmission function within the corresponding frequency band, it is necessary to find a resonant structure with low reflection or high transmittance as the topological array unit of the metamaterial. The present invention provides a new broadband energy transmission window, abandoning the method of dielectric constant matching through multiple window sheets to expand the bandwidth in the past. This design adopts a periodic array structure loading to achieve the electromagnetic resonance response within the corresponding frequency band, with broadband and low-loss characteristics. At the same time, this design simplifies the welding complexity in the manufacturing process and improves the yield.

[0038] In view of this, the present invention first provides an energy transmission window. Specifically, referring to Figures 3 to 5 as shown, the energy transmission window includes two dielectric substrates 1, and an electromagnetic resonance unit 2 clamped and fixed between the two dielectric substrates 1, that is, the two dielectric substrates 1 are respectively fixed on two opposite sides of the electromagnetic resonance unit 2. The electromagnetic resonance unit 2 includes a plurality of resonant units 3 arranged in an array. The resonant unit 3 includes a first metal ring 31 having a first opening 311, and a second metal ring 32 located inside the first metal ring 31 and having a second opening 321.

[0039] A single metal ring can generate an induced current in a perpendicular magnetic field, but it cannot have a resonant response. However, a metal ring structure with an opening forms a resonant circuit by introducing capacitance, thereby achieving a resonant response. Since the introduction of capacitance will accumulate charges on both sides of the metal ring opening to form an electric dipole moment, further, in the present invention, the first opening 311 and the second opening 321 are arranged in opposite directions. The present invention uses two metal rings placed in opposite directions and having complementary openings to reduce unnecessary electric dipole moments, so that the metamaterial unit can generate a strong electromagnetic response at a specific frequency. The specific structure of the resonant unit 3 is as Figure 4 shown.

[0040] In the present invention, the resonant unit 3 has a symmetric structure and is composed of a first metal ring 31 and a second metal ring 32 arranged concentrically to form a complementary metal resonant ring. These two metal rings are located between the dielectric substrates 1 to form a sandwich structure similar to a sandwich. This structure can be described by the method of an equivalent circuit. The opening part of the resonant unit is approximately two capacitors connected in series, denoted as , and the ring body part of the metal ring is approximately an inductor, denoted as . Therefore, the resonant response frequency can be expressed as: , Therefore, by changing the opening width and the structural dimensions of the metal ring, the resonance frequency can be flexibly adjusted.

[0041] In the present invention, the resonance response means that each complementary opening resonance unit has independent resonance characteristics, which are determined by the geometric parameters (such as size, shape, spacing, etc.) and material properties of each resonance unit. This resonance response is manifested as a local enhancement of the field distribution within a specific frequency range, forming an electromagnetic resonance mode with a high quality factor. The resonance response of a single resonance unit 3 mainly solves its frequency selectivity and local electromagnetic performance within a specified band.

[0042] The electromagnetic resonance response is the overall performance after several resonance units 3 are arranged in an array. That is, after multiple resonance units 3 are arranged in a periodic array, the overall electromagnetic resonance response generated by the interaction (including electromagnetic coupling and interference) between the resonance units 3. The electromagnetic resonance after array formation is the result of the resonance modes of multiple resonance units acting together through periodic arrangement.

[0043] Furthermore, the selection of the number N of resonance units 3 directly affects the performance of the periodic array electromagnetic resonance unit 2, including the working bandwidth, transmission efficiency, etc. The relationship between the length (size) of the electromagnetic resonance unit and the bandwidth is that the electromagnetic resonance unit 2 formed after several resonance units 3 arranged in an array achieves the bandwidth effect through the gradual impedance matching between the resonance units 3. The more the number of resonance units, the smoother the gradient, and the better the coverage effect on the bandwidth, that is, △f∝N, where △f is the bandwidth and N is the number of resonance units, that is, the two are approximately in a proportional relationship.

[0044] In one embodiment, a first spacing space 4 is provided between the ring bodies of the first metal ring 31 and the second metal ring 32; a second spacing space 5 is provided between two adjacent resonance units 3. The first metal ring 31 and the second metal ring 32 are concentrically arranged. The design of these spacing spaces (i.e., the first spacing space 4 and the second spacing space 5) has multiple functions. First of all, they can flexibly adjust the electromagnetic coupling strength according to the design requirements, thereby optimizing the resonance characteristics. Secondly, the spacing spaces can be used to control the overall size and density of the structure to adapt to different application scenarios. In addition, by adjusting the size of the spacing spaces, the complexity of the manufacturing process can be effectively reduced, and the production efficiency and the yield rate can be improved. This flexibility enables the present invention to exhibit excellent performance under different frequency bands and working conditions.

[0045] In one embodiment, the first openings 311 of a plurality of first metal rings 31 face the same direction, and the second openings 321 of a plurality of second metal rings 32 also face the same direction. This design ensures that the first metal rings 31 and the second metal rings 32 are arranged periodically in the electromagnetic resonance unit 2, maintaining consistency. In this way, not only the integrity and stability of the structure are improved, but also the processing difficulty in the manufacturing process is effectively reduced. Specifically, the unified opening direction simplifies the alignment steps in the manufacturing process, reduces errors, thereby improving the production efficiency and the yield. In addition, this periodic arrangement helps to optimize the electromagnetic field distribution, enhance the resonance effect, and further improve the performance of the energy transmission window.

[0046] Furthermore, in one embodiment, according to the structure of the low-reflection unit, the present invention arranges the resonance units 3 in a periodic topology, and utilizes the resonance effect between the resonance units 3 to cover a wide frequency range, thereby achieving broadband characteristics. A plurality of resonance units 3 are arranged in a regular array in the plane formed by the electromagnetic resonance unit 2. This design can not only effectively expand the working bandwidth, but also improve the uniformity and stability of the electromagnetic response, and is easy to process and manufacture. And by precisely controlling the distance and arrangement mode between the resonance units, the electromagnetic field distribution can be optimized and the resonance effect can be enhanced, as Figure 5 shown.

[0047] In addition, to further consider the coupling effect between adjacent units, the present invention further optimizes and adjusts the electromagnetic resonance unit 2 composed of a plurality of resonance units 3 arranged in an array. Specifically, the electromagnetic resonance unit 2 includes an intermediate arrangement area 21 and a side arrangement area 22 located at the edge of the intermediate arrangement area 21. The intermediate arrangement area 21 is arranged in a rectangular array. The side arrangement area 22 adopts a gradient array arrangement mode. Preferably, the side arrangement area 22 is arranged in a linear gradient array, because the edge effect generated at the contour boundary of the array has a greater impact on the transmission performance of the metamaterial window. By selecting a periodic combination with a gradient change arrangement mode, the electric field energy can be evenly transmitted, thereby reducing unnecessary reflection and scattering losses.

[0048] The microwave transmission performance of the energy transmission window is simulated using a commercial electromagnetic simulation software. Figure 6 The reflection loss S of the existing three-layer sapphire window and the energy transmission window provided by the present invention is plotted under the same window diameter. 11 The calculation results show that under the same low-loss level, the bandwidth of the energy transmission window provided by the present invention is significantly wider.

[0049] To clearly demonstrate the beneficial effects of the technical solution of the present invention, Table 1 compares the existing multi-layer sapphire window with the energy transmission window provided by the present invention. The present invention not only has remarkable achievements in bandwidth expansion, but also abandons the air gap required by the traditional multi-layer technology, reduces the welding thickness, and to a certain extent reduces the manufacturing cost.

[0050] Table 1 Comparison between the existing multi-layer sapphire energy transmission window and the energy transmission window of the present invention

[0051]

[0052] Combined with Table 1 shown above, in a specific example of the present invention, with the same structural dimensions of the energy transmission window and the same working mode, the energy transmission window of the present invention uses boron nitride ceramic with a thickness of 0.34 mm as the dielectric substrate. To achieve the broadband effect, the outer radius of the first metal ring is 0.75 mm, the outer radius of the second metal ring is 0.6 mm, the ring body diameter of the first metal ring is 0.05 mm, the ring body diameter of the second metal ring is 0.05 mm, the opening width of the first opening on the first metal ring is 1 mm, and the opening width of the second opening on the second metal ring is 0.3 mm. Considering the influence of the electromagnetic resonance unit boundary on the reflection coefficient, the electromagnetic resonance unit includes a middle arrangement area and a side arrangement area located at the edge of the middle arrangement area. The middle arrangement area is arranged in a rectangular array, while the side arrangement area adopts a gradient array arrangement method. The boundary of the electromagnetic resonance unit forms a polygonal contour. The simulation results show that under this structure, the reflection loss S can be achieved in the frequency range of 79.44 - 101.01 GHz 11 <-20 dB, with a relative bandwidth of 23.9%. Compared with the existing energy transmission window, the overall thickness is significantly reduced, the bandwidth is expanded by at least more than 2 times, and it can effectively solve the problem of difficult processing caused by the reduction of the thickness of the window dielectric material due to the increase of the working frequency. It has a low manufacturing cost, is flexible and tunable in design, has strong universality, and can be applied to the energy transmission systems of various broadband vacuum electronic devices.

[0053] In one embodiment, the material of the dielectric substrate 1 includes but is not limited to beryllium oxide and boron nitride. The material of the first metal ring 31 includes but is not limited to those with strong conductivity and small conductor loss, such as gold, silver, copper, etc. The material of the second metal ring 32 includes but is not limited to those with strong conductivity and small conductor loss, such as gold, silver, copper, etc. The material of the first metal ring 31 is the same as or different from the material of the second metal ring 32.

[0054] In one embodiment, the ring body diameter of the first metal ring 31 is equal to or not equal to the ring body diameter of the second metal ring 32. The central angle corresponding to the first opening 311 is the same as or different from the central angle corresponding to the second opening 321.

[0055] According to another object of the present invention, the present invention also provides a method for manufacturing an energy transmission window, the method comprising the following steps:

[0056] S1. Provide a first dielectric substrate, and provide a metal layer on one side surface of the first dielectric substrate, the metal layer covering the surface of the first dielectric substrate;

[0057] S2. By an etching process, form electromagnetic resonance units on the metal layer;

[0058] S3. Provide a second dielectric substrate, and fix the second dielectric substrate on the side of the electromagnetic resonance units away from the first dielectric substrate to obtain the energy transmission window.

[0059] In one embodiment, the electromagnetic resonance units 2 include a plurality of resonant units 3 arranged in an array; the resonant unit 3 includes a first metal ring 31 having a first opening 311 and a second metal ring 32 having a second opening 321 located inside the first metal ring 31. Preferably, the first metal ring 31 and the second metal ring 32 are concentrically arranged.

[0060] The energy transmission window structure provided by the present invention can be widely applied to the energy transmission systems of various broadband vacuum electronic devices such as klystrons, traveling wave tubes, and gyro-traveling wave tubes, and can significantly expand the working bandwidth without increasing the volume of the energy transmission window components.

[0061] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, rather than limitations on the embodiments of the present invention. For those of ordinary skill in the art, other different forms of changes or modifications can be made based on the above description. It is impossible to list all the embodiments here. Any obvious changes or modifications derived from the technical solutions of the present invention still fall within the protection scope of the present invention.

Claims

1. An energy transmission window, characterized in that, The energy transmission window includes two dielectric substrates, and an electromagnetic resonance unit clamped and fixed between the two dielectric substrates; The electromagnetic resonance unit includes a plurality of resonant units arranged in an array; The resonant unit includes: a first metal ring having a first opening, and a second metal ring having a second opening located inside the first metal ring; The dielectric substrate has a plate-like structure and is used for clamping and fixing the electromagnetic resonance unit; The dielectric substrate is made of a non-metallic material.

2. The energy transmission window according to claim 1, wherein The first opening and the second opening are arranged in opposite directions.

3. The energy transmission window according to claim 1, characterized in that, There is a first spaced space between the ring body of the first metal ring and the ring body of the second metal ring; there is a second spaced space between adjacent resonant units, and the first metal ring and the second metal ring are concentrically arranged.

4. The energy transmission window according to claim 1, characterized in that, The first opening directions of a plurality of first metal rings face the same direction.

5. The energy transmission window according to claim 1, characterized in that, The second opening directions of a plurality of second metal rings face the same direction.

6. The energy transmission window according to claim 1, characterized in that, A plurality of resonant units are arranged in a regular array in the plane formed by the electromagnetic resonance unit.

7. The energy transmission window according to claim 1, wherein The electromagnetic resonance unit includes an intermediate arrangement area and a side arrangement area located at the edge of the intermediate arrangement area; The intermediate arrangement area is arranged in a rectangular array, and the side arrangement area is arranged in a gradient array.

8. A manufacturing method of an energy transmission window according to any one of claims 1-7, characterized in that, It includes the following steps: S1. Provide a first dielectric substrate, and a metal layer is provided on one surface of the first dielectric substrate, and the metal layer covers this surface of the first dielectric substrate; S2. Through an etching process, the metal layer forms an electromagnetic resonance unit; S3. Provide a second dielectric substrate, and the second dielectric substrate is fixed on the side of the electromagnetic resonance unit facing away from the first dielectric substrate to obtain the energy transmission window.

9. The manufacturing method according to claim 8, wherein, The electromagnetic resonance unit includes a plurality of resonant units arranged in an array; the resonant unit includes a first metal ring having a first opening and a second metal ring having a second opening located inside the first metal ring.

10. The manufacturing method according to claim 9, characterized in that, The first metal ring and the second metal ring are concentrically arranged.

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