Energy transmission window and manufacturing method thereof

Abstract

The embodiment of the invention discloses an energy transmission window and a manufacturing method of the energy transmission window. The energy transmission window comprises two dielectric substrates and an electromagnetic resonance unit clamped and fixed between the two dielectric substrates. The electromagnetic resonance unit comprises a plurality of resonance units arranged in an array; the resonance unit comprises a first metal circular ring with a first opening and a second metal circular ring which is arranged in the first metal circular ring and is provided with a second opening. The problems that an existing energy transmission window is large in design difficulty, complex in process, high in cost and the like are effectively solved, and the working bandwidth can be remarkably expanded under the condition that the size of an energy transmission window component is not increased.

Description

Technical Field

[0001] The present invention relates to the field of microwave vacuum electronic technology, and more specifically, to an energy transmission window and a method for manufacturing the energy transmission window. Background Art

[0002] Microwave amplifiers play a key role in many fields such as wireless communications, radar systems, satellite communications, and scientific research. Their operating bandwidth is closely related to the bandwidth of the energy transmission window. Today's long-range millimeter-wave high-resolution imaging radars require a wider relative bandwidth, which is difficult to achieve for energy transmission windows of traditional structures. Traditional single-layer energy transmission windows can only achieve narrowband transmission due to the impedance mismatch on both sides of the waveguide. From a design perspective, in order to expand the bandwidth, a multi-layer window structure design is often used. Introducing dielectric materials on both sides of the original waveguide can achieve better matching, such as Figure 1 shown.

[0003] However, since the dielectric constant of the material itself is constant, this limits the dielectric matching between multi-layer windows, making the design of broadband energy transmission windows very difficult. From a process perspective, the welding of multi-layer window structures is complex, and there are high precision requirements for the spacing between adjacent window pieces, which leads to low yields. In addition, the problem of how to exhaust (maintain a vacuum state) between the window pieces must be fully considered. When the device is in a high-power working state, there is a risk of vacuum breakdown.

[0004] To this end, a broadband energy transmission window with a metasurface structure was subsequently proposed. Figure 2 As shown in the figure, this type of energy transmission window loads periodic columnar loading units on both sides of the circular uniform medium in the middle. By changing the height of the matching layer (periodic columnar loading unit) and the structural dimensions of the columnar loading unit (radial size, material, and gap between columnar loading units), the matching dielectric constant can be adjusted arbitrarily, thereby achieving a better matching effect to achieve the purpose of expanding bandwidth. However, this metasurface structure has extremely high requirements for the precision of the matching layer, is difficult to design, has high manufacturing costs, and is not conducive to processing and realization.

[0005] Therefore, it is necessary to break through the bottlenecks of existing technologies such as narrow bandwidth, reliance on inherent material properties, and difficulty in processing and welding, so as to improve the working performance of vacuum electronic devices and give full play to their advantages in millimeter wave and even terahertz frequency bands. Summary of the invention

[0006] One object of the present invention is to provide an energy transmission window that can effectively expand the device's operating bandwidth while greatly reducing the difficulty of the energy transmission window manufacturing process, and can be flexibly designed according to the device's operating wavelength, frequency band, bandwidth and other technical requirements.

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

[0008] In order to achieve the above object, the present invention adopts the following technical solutions: According to the first object of the present invention, the present invention first provides an energy transmission window, the energy transmission window comprising two dielectric substrates, and an electromagnetic resonance unit sandwiched and fixed between the two dielectric substrates; The electromagnetic resonance unit includes a plurality of resonance units arranged in an array; The resonance unit comprises: a first metal ring having a first opening, and A second metal ring with a second opening is located inside the first metal ring.

[0009] In addition, a preferred solution is that the first opening and the second opening are arranged back to back.

[0010] In addition, a preferred solution is that a first spacing space is included between the first metal ring body and the second metal ring body; a second spacing space is included between two adjacent resonance units, and the first metal ring and the second metal ring are arranged concentrically.

[0011] In addition, a preferred solution is that the first opening directions of the plurality of first metal rings face the same direction.

[0012] In addition, a preferred solution is that the second opening directions of the plurality of second metal rings face the same direction.

[0013] In addition, a preferred solution is that a plurality of resonance units are arranged in a regular row within a plane formed by the electromagnetic resonance unit.

[0014] In addition, a preferred solution is that 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, and the side arrangement area is arranged in a gradient array.

[0015] According to the second object of the present invention, the present invention also provides a method for manufacturing an energy transmission window, comprising the following steps: S1. Provide a first dielectric substrate, and arrange a metal layer on a surface of one side of the first dielectric substrate, wherein the metal layer covers the surface of the first dielectric substrate; S2. The metal layer forms an electromagnetic resonance unit through an etching process; S3. Provide a second dielectric substrate, wherein the second dielectric substrate is fixed to a side of the electromagnetic resonance unit facing away from the first dielectric substrate, to obtain the energy transmission window.

[0016] In addition, a preferred solution is that the electromagnetic resonance unit includes a plurality of resonance units arranged in an array; the resonance unit includes a first metal ring with a first opening, and a second metal ring with a second opening located inside the first metal ring.

[0017] In addition, a preferred solution is that the first metal ring and the second metal ring are arranged cocentrically.

[0018] The beneficial effects of the present invention are as follows: The present invention provides a new energy transmission window structure, which is composed of a resonance unit formed by a first metal ring and a second metal ring, and an electromagnetic resonance unit is formed by using a plurality of resonance units. This design effectively solves the problems of the existing energy transmission window in terms of difficulty in design, complex process and high cost. The energy transmission window structure can be widely used in a variety of wide-band vacuum electronic device energy transmission systems such as klystrons, traveling wave tubes and gyrotron traveling wave tubes, and can significantly expand the working bandwidth without increasing the volume of the energy transmission window components. Its high design flexibility and universal application make it helpful to improve the yield rate in the mass production process. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The specific implementation modes of the present invention are further described in detail below in conjunction with the accompanying drawings.

[0020] Figure 1 A conventional energy transmission window structure is shown.

[0021] Figure 2 Another existing energy transmission window structure is shown.

[0022] Figure 3 It is shown that the present invention provides an overall structure of an energy transmission window.

[0023] Figure 4 A schematic structural diagram of a resonance unit in an energy transmission window structure provided by the present invention is shown.

[0024] Figure 5 A schematic structural diagram of the electromagnetic resonance unit in the energy transmission window structure provided by the present invention is shown.

[0025] Figure 6 A reflection coefficient result diagram of the energy transmission window electromagnetic simulation software is provided for the present invention. DETAILED DESCRIPTION

[0026] In order to more clearly illustrate the present invention, the present invention is further described below in conjunction with preferred embodiments and accompanying drawings. Similar components in the accompanying drawings are represented by the same reference numerals. It should be understood by those skilled in the art that the content specifically described below is illustrative rather than restrictive, and should not be used to limit the scope of protection of the present invention.

[0027] In order to realize 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, which abandons the previous method of matching dielectric constants through multi-layer windows to expand the bandwidth. The design adopts periodic array structure loading to realize electromagnetic resonance response within the corresponding frequency band, and has broadband and low loss characteristics. At the same time, this design simplifies the welding complexity in the manufacturing process and improves the yield rate.

[0028] 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 sandwiched 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 resonance units 3 arranged in an array. The resonance unit 3 includes a first metal ring 31 with a first opening 311, and a second metal ring 32 with a second opening 321 located in the first metal ring 31.

[0029] A single metal ring can generate an induced current in a vertical magnetic field, but it cannot have a resonant response. However, the metal ring structure with an opening forms a resonant circuit by introducing a capacitor, thereby achieving a resonant response. Since the introduction of the capacitor will accumulate charges on both sides of the metal ring opening to form an electric dipole moment, further, the first opening 311 and the second opening 321 in the present invention are arranged back to back. The present invention uses two metal rings placed in opposite directions and with 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 follows: Figure 4 shown.

[0030] In the present invention, the resonance unit 3 is symmetrically structured, and is composed of a first metal ring 31 and a second metal ring 32 arranged concentrically to form a complementary metal resonance ring. The two metal rings are located between the dielectric substrate 1 to form a sandwich structure similar to a sandwich structure. The structure can be described by an equivalent circuit method, and the opening part of the resonance unit is approximately two capacitors in series, which are recorded as , the metal ring body is approximately an inductor, recorded as Therefore, the resonant response frequency can be expressed as: ,Therefore, the resonant frequency can be flexibly adjusted by changing the opening width and the structural dimensions of the metal ring.

[0031] In the present invention, the resonant response means that each complementary open resonant unit has an independent resonant characteristic, which is determined by the geometric parameters (such as size, shape, spacing, etc.) and material properties of each resonant unit. This resonant response is manifested in the local enhancement of the field distribution within a specific frequency range, forming an electromagnetic resonance mode with a high quality factor. The resonant response of a single resonant unit 3 mainly solves its frequency selectivity and local electromagnetic performance within a specified band.

[0032] The electromagnetic resonance response is the overall performance of a number of resonance units 3 arranged in an array, that is, after a plurality of 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 is generated. The electromagnetic resonance after the array is the result of the joint action of the resonance modes of a plurality of resonance units through periodic arrangement.

[0033] 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) and the bandwidth of the electromagnetic resonance unit is that the electromagnetic resonance unit 2 formed by a plurality of resonance units 3 arranged in an array realizes the bandwidth effect through the gradual impedance matching between the resonance units 3. The more resonance units there are, the smoother the gradual change is, and the better the coverage effect of the bandwidth is, that is, △f∝N, where △f is the bandwidth and N is the number of resonance units, that is, the two can be approximately proportional.

[0034] In one embodiment, a first spacing space 4 is provided between 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 arranged concentrically. The design of these spacing spaces (i.e., the first spacing space 4 and the second spacing space 5) has multiple functions. First, they can flexibly adjust the electromagnetic coupling strength according to the design requirements, thereby optimizing the resonance characteristics. Secondly, the spacing space 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 space, the complexity of the manufacturing process can be effectively reduced, and the production efficiency and yield rate can be improved. This flexibility enables the present invention to exhibit excellent performance in different frequency bands and working conditions.

[0035] In one embodiment, the first openings 311 of several first metal rings 31 are oriented in the same direction, and the second openings 321 of several second metal rings 32 are also oriented in 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 to maintain consistency. In this way, not only the integrity and stability of the structure are improved, but also the process difficulty in processing is effectively reduced. Specifically, the unified opening direction simplifies the alignment steps in the manufacturing process, reduces errors, and thus improves production efficiency and 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.

[0036] Furthermore, in one embodiment, the present invention arranges the resonance units 3 in a periodic topological manner according to the structure of the low-reflection unit, and utilizes the resonance effect between the resonance units 3 to cover a wide frequency range, thereby achieving broadband characteristics. Several resonance units 3 are arranged in a straight line 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 between the resonance units, the electromagnetic field distribution can be optimized and the resonance effect can be enhanced, such as Figure 5 shown.

[0037] In addition, in order to further consider the coupling effect between adjacent units, the present invention further optimizes and adjusts the electromagnetic resonance unit 2 composed of a number of resonance units 3 arranged in an array. Specifically, the electromagnetic resonance unit 2 includes a middle arrangement area 21 and a side arrangement area 22 located at the edge of the middle arrangement area 21. The middle arrangement area 21 is arranged in a rectangular array. The side arrangement area 22 adopts a gradient array arrangement. Preferably, the side arrangement area 22 is arranged in a linear gradient array. This is because the edge effect generated at the contour boundary of the array has a greater influence on the transmission performance of the metamaterial window. By selecting an arrangement method with a gradient change for periodic combination, the electric field energy can be evenly transmitted, thereby reducing unnecessary reflection and scattering losses.

[0038] Commercial electromagnetic simulation software is used to simulate the microwave transmission performance of the energy transmission window. Figure 6 The reflection loss S of the existing three-layer sapphire window and the energy transmission window provided by the present invention under the same window diameter is plotted. 11 From the calculation results, it can be seen that under the same low loss level, the bandwidth of the energy transmission window provided by the present invention is significantly wider.

[0039] In order to clearly show the beneficial effects of the technical solution of the present invention, the existing multi-layer sapphire window is compared with the energy transmission window provided by the present invention in Table 1. The present invention not only has significant results in bandwidth expansion, but also abandons the air gap required by the traditional multi-layer technology, reduces the welding thickness, and reduces the manufacturing cost to a certain extent.

[0040] Table 1 Comparison between existing multi-layer sapphire energy transmission window and the energy transmission window of the present invention

[0041] Combined with the above Table 1, in a specific example of the present invention, when the energy transmission window has the same structural dimensions and the same working mode, the energy transmission window of the present invention uses a boron nitride ceramic with a thickness of 0.34 mm as a dielectric substrate. In order to achieve a 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 diameter of the first metal ring body is 0.05 mm, the diameter of the second metal ring body 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 boundary of the electromagnetic resonance unit 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, and the side arrangement area adopts a gradient array arrangement method. The boundary of the electromagnetic resonance unit constitutes a polygonal contour. The simulation results show that the reflection loss S can be achieved in the frequency range of 79.44-101.01 GHz under this structure. 11 <-20dB, 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 2 times, and it can effectively solve the problem of processing difficulties caused by the increase in operating frequency, which makes the thickness of the window dielectric material smaller. It has low manufacturing cost, flexible and tunable design, strong universality, and can be applied to a variety of broadband vacuum electronic device energy transmission systems.

[0042] In one embodiment, the material of the dielectric substrate 1 includes but is not limited to oxide skin and boron nitride. The material of the first metal ring 31 includes but is not limited to materials with strong conductivity and low conductor loss such as gold, silver, copper, etc. The material of the second metal ring 32 includes but is not limited to materials with strong conductivity and low 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.

[0043] In one embodiment, the diameter of the first metal ring 31 is equal to or different from the diameter of the second metal ring 32. The central angle corresponding to the first opening 311 is equal to or different from the central angle corresponding to the second opening 321.

[0044] According to another object of the present invention, the present invention further provides a method for manufacturing an energy transmission window, the method comprising the following steps: S1. Provide a first dielectric substrate, and dispose a metal layer on one side of the first dielectric substrate, wherein the metal layer covers the surface of the first dielectric substrate; S2. The metal layer forms an electromagnetic resonance unit through an etching process; S3. Provide a second dielectric substrate, wherein the second dielectric substrate is fixed to a side of the electromagnetic resonance unit facing away from the first dielectric substrate, to obtain the energy transmission window.

[0045] In one embodiment, the electromagnetic resonance unit 2 includes a plurality of resonance units 3 arranged in an array; the resonance 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 arranged concentrically.

[0046] The energy transmission window structure provided by the present invention can be widely used in various broadband vacuum electronic device energy transmission systems such as klystrons, traveling wave tubes and gyrotron traveling wave tubes, and can significantly expand the working bandwidth without increasing the volume of the energy transmission window components.

[0047] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not limitations on the implementation methods of the present invention. For ordinary technicians in the relevant field, other different forms of changes or modifications can be made based on the above description. It is impossible to list all the implementation methods here. All obvious changes or modifications derived from the technical solution of the present invention are still within the protection scope of the present invention.

Claims

1. An energy transmission window, characterized in that: The energy transmission window comprises two dielectric substrates, and an electromagnetic resonance unit sandwiched and fixed between the two dielectric substrates; The electromagnetic resonance unit includes a plurality of resonance units arranged in an array; The resonance unit comprises: a first metal ring having a first opening, and A second metal ring with a second opening is located inside the first metal ring.

2. The energy transmission window according to claim 1, characterized in that: The first opening and the second opening are arranged back to back.

3. The energy transmission window according to claim 1, characterized in that: A first spacing space is included between the first metal ring body and the second metal ring body; a second spacing space is included between two adjacent resonance units, and the first metal ring and the second metal ring are arranged concentrically.

4. The energy transmission window according to claim 1, characterized in that: The first opening directions of the 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 the 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 row in a plane formed by the electromagnetic resonance unit.

7. The energy transmission window according to claim 1, characterized in that: 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, and the side arrangement area is arranged in a gradient array.

8. A method for manufacturing an energy transmission window, characterized in that: The steps include: S1. Provide a first dielectric substrate, and arrange a metal layer on a surface of one side of the first dielectric substrate, wherein the metal layer covers the surface of the first dielectric substrate; S2. The metal layer forms an electromagnetic resonance unit through an etching process; S3. Provide a second dielectric substrate, wherein the second dielectric substrate is fixed to a 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, characterized in that: The electromagnetic resonance unit includes a plurality of resonance units arranged in an array; the resonance unit includes a first metal ring with a first opening, and a second metal ring with 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 arranged cocentrically.

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