Stepped transmission band line shielding cavity resonance suppression structure

Abstract

The invention relates to the technical field of microwave communication, in particular to a stepped transmission band line shielding cavity resonance suppression structure, which comprises a shielding shell provided with an open accommodating cavity; the transmission band line is arranged in the accommodating cavity of the shielding shell; and the shielding cover plate is used for covering the shielding shell, and a convex block is integrally formed on the lower surface of the shielding cover plate. The bump structure is integrally formed on the shielding cover plate, so that resonance suppression of the shielding cavity is realized, and the influence of cavity resonance on the performance of the transmission band line can be reduced or even eliminated through introduction of the bump structure.

Description

Technical Field

[0001] The present invention relates to the technical field of microwave communication, and particularly to a stepped transmission line shielding cavity resonance suppression structure. Background Art

[0002] In recent years, microwave communication has developed rapidly in both military and civilian fields, and the microwave electromagnetic environment has become increasingly complex. In order to improve the anti-interference ability of microwave products themselves, most existing microwave product designs adopt integrated SIP modules or are directly packaged into a surface mount device. However, no matter what kind of integration method is used, the signal transmission connection between modules and devices is still indispensable. The commonly used signal transmission type is PCB microstrip line transmission, and the electromagnetic interference resistance of the microstrip line is often solved by installing the microstrip line PCB in a microwave shielding cavity. However, due to the inherent resonance frequency of the microwave shielding cavity, if this frequency overlaps with the transmission frequency band of the microstrip line, it will affect the signal transmission performance of the microstrip line. Therefore, it is particularly important to study the resonance suppression method of the transmission line shielding cavity.

[0003] Currently, the commonly used methods for suppressing the resonance of the transmission line shielding cavity are as follows:

[0004] First: Absorbing materials are pasted on the shielding cavity cover plate, and its use method is flexible and convenient. It is the most commonly used method in microwave product design.

[0005] Second: A specific structure is made on the cavity to achieve the resonance suppression effect of the shielding cavity. This method is an effective resonance suppression method, and good materials will not have problems with long-term storage deformation in terms of structure. For example, the cavity resonance suppression structure in the patent application with the publication number CN105470618A is a non-contact extended covering structure.

[0006] Third: The resonance suppression effect of the shielding cavity is achieved by adding a third entity or structure. This method is commonly used in the industry. For example, the patent application with the publication number CN111740204A discloses a cavity resonance suppression structure and its application, in which a resistance film and a resonance ring family are added to the bottom of the air cavity of a three-dimensional heterogeneous integrated radio frequency structure to achieve resonance suppression. Another example is that the patent application with the publication number CN115426056A discloses a resonance suppression circuit and an electronic product, and a dielectric unit circuit board with a preset distributed capacitance tuning structure and metal vias is added to achieve resonance suppression.

[0007] The first method of pasting absorbing materials is the most commonly used. However, for most existing products, the storage period is required to be more than 10 years, which poses extremely high requirements on the storage characteristics of the absorbing materials and the bonding performance of the paste installation method, and there are certain risks.

[0008] The cavity harmonic suppression methods proposed in the above-mentioned prior arts CN105470618A, CN111740204A, and CN115426056A are all used under specific structural products and application conditions, with poor universality. In the prior arts CN111740204A and CN115426056A, resonance suppression is achieved by adding a third-party entity, resulting in a complex structure and an increase in the cost of implementing the resonance suppression function, with a relatively low cost performance. Summary of the Invention

[0009] The main object of the present invention is to propose a stepped transmission line shielded cavity resonance suppression structure, aiming to solve the above technical problems.

[0010] To achieve the above object, the present invention proposes a stepped transmission line shielded cavity resonance suppression structure, including: a shield housing, the shield housing having an open accommodation cavity; a transmission line installed in the accommodation cavity of the shield housing; a shield cover plate for covering the shield housing, and a convex block is integrally formed on the lower surface of the shield cover plate.

[0011] Preferably, both the shield housing and the shield cover plate are processed from materials with electromagnetic shielding functions.

[0012] Preferably, the materials of both the shield housing and the shield cover plate are aluminum alloy.

[0013] Preferably, the convex block is in the shape of a cuboid.

[0014] Optionally, n-level steps are integrally formed on the left and right side surfaces of the convex block, where n is a positive integer.

[0015] Further, the number of steps on the left and right side surfaces of the convex block is 1 level.

[0016] Preferably, the transmission line is a 50-ohm transmission line for microwave signal transmission.

[0017] Preferably, the types of the transmission line include microstrip line, stripline, and coplanar waveguide.

[0018] Preferably, through holes are respectively opened at the left and right ends of the shield housing for installing SMA connectors for performance testing.

[0019] Preferably, the transmission line includes a dielectric substrate and a conductive strip disposed on the dielectric substrate; the dielectric substrate is connected to the inner cavity bottom wall of the shield housing by means of screw assembly, or bonding, or sintering, or welding.

[0020] Due to the adoption of the above technical solutions, the beneficial effects of the present invention are as follows:

[0021] (1) In the present invention, by integrally forming a bump structure on the shielding cover plate, the resonance suppression of the shielding cavity is realized. The introduction of this bump structure will reduce or even eliminate the influence of cavity resonance on the performance of the transmission line.

[0022] (2) In the present invention, n - level steps are integrally formed on the left and right sides of the bump, where n is a positive integer. Thus, the entire bump forms a stepped structure. The resonance suppression of the shielding cavity is realized through the stepped structure. The introduction of this stepped structure will reduce or even eliminate the influence of cavity resonance on the performance of the transmission line. In the present invention, the stepped structure is simple, without order constraints. Under possible circumstances, it can be arbitrarily constructed between 1 - order and infinite - order according to performance requirements, having good flexibility.

[0023] (3) The bump is arranged on the bottom surface of the shielding cover plate in an integrally formed manner. As long as the bump is arranged in the inner cavity of the shielding housing, the specific position and quantity of the bump are not fixed. Under possible circumstances, the physical position of the bump structure on the bottom surface of the shielding cover plate and the quantity of the placed bump structures can be designed according to the actual engineering structure and requirements.

[0024] (4) In the present invention, the bump is arranged on the bottom surface of the shielding cover plate, which has little influence on the design and layout of the accommodating cavity of the shielding housing and the transmission line inside it. It is relatively independent in structure and is convenient for design.

[0025] (5) In the present invention, the bump and the shielding cover plate adopt an integrally formed structural design, that is, the bump and the shielding cover plate belong to the same processed part. Compared with the prior art, no third - party entity is introduced, no new materials and processes are introduced. The cost generated by realizing the resonance suppression function of the shielding cavity is reduced to the greatest extent, having good economy.

[0026] (6) By adopting the structure of integrally forming a bump on the shielding cover plate and the stepped structure formed by integrally forming steps on the left and right sides of the bump, it has a good effect on the resonance suppression of the shielding cavity.

[0027] (7) Since steps are arranged on both sides of the bump, forming a stepped structure, the resonance suppression of the transmission - line shielding cavity is realized by loading the shielding cover plate with the stepped structure, reducing the influence of shielding - cavity resonance on the performance of the transmission line. The transmission line is the most basic signal - transmission connection method in the circuit system, and all microwave products will involve it. This method is applicable to all transmission lines with shielding cavities. The suppression structure is loaded on the shielding cover plate, which is relatively independent, and is convenient for processing, replacement and adjustment, without affecting the circuit layout and wiring design. At the same time, this structure is not restricted by the circuit design. Description of the Drawings

[0028] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on the structures shown in these drawings.

[0029] Figure 1 It is a schematic diagram of the structural decomposition of the present invention;

[0030] Figure 2 It is a schematic diagram of the structure of the shielding housing in the present invention;

[0031] Figure 3 It is a schematic diagram of the structure of the shielding cover plate in the first embodiment of the present invention;

[0032] Figure 4 It is a schematic diagram of the structure of the transmission belt line in the present invention;

[0033] Figure 5 It is a schematic diagram of the structure of the shielding cover plate in the second embodiment of the present invention;

[0034] Figure 6 It is a front view of the shielding cover plate in the second embodiment of the present invention;

[0035] Figure 7 It is a bottom view of the shielding cover plate in the second embodiment of the present invention;

[0036] Figure 8 It is a transmission performance diagram when no bump is provided on the bottom surface of the shielding cover plate;

[0037] Figure 9 It is a transmission performance diagram when a bump with a first-level step is provided on the bottom surface of the shielding cover plate in the second embodiment of the present invention.

[0038] Explanation of the reference numerals in the drawings: 1. Shielding housing; 101. Accommodation cavity; 102. Through hole; 2. Shielding cover plate; 201. Bump; 3. Transmission belt line; 301. Conductive strip; 302. Dielectric substrate. Detailed implementation manners

[0039] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, rather than all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present invention.

[0040] It should be noted that all directional indications (such as up, down, left, right, front, back...) in the embodiments of the present invention are only used to explain the relative positional relationship and movement conditions between components in a specific posture (as shown in the drawings). If the specific posture changes, the directional indications will also change accordingly.

[0041] In addition, the descriptions involving "first", "second", etc. in the present invention are only for descriptive purposes and should not be construed as indicating or implying their relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include at least one such feature. In addition, the technical solutions between various embodiments can be combined with each other, but it must be based on the ability of those of ordinary skill in the art to implement. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0042] Embodiment 1:

[0043] Combined with Figures 1 to 4 As shown in the figure, the first embodiment of a stepped transmission line shielding cavity resonance suppression structure provided by the present invention includes: a shielding housing 1, the shielding housing 1 having an open accommodation cavity 101; a transmission line 3 installed in the accommodation cavity 101 of the shielding housing 1; and a shielding cover plate 2 for covering the shielding housing 1, with a convex block 201 integrally formed on the lower surface of the shielding cover plate 2.

[0044] In this embodiment, both the shielding housing 1 and the shielding cover plate 2 are processed from materials with electromagnetic shielding functions. Specifically, the materials of the shielding housing 1 and the shielding cover plate 2 are both aluminum alloy.

[0045] Combined with Figure 3 As shown in the figure, in this embodiment, the convex block 201 is in the shape of a cuboid. The bottom surface of the convex block 201 forms a stepped surface F relative to the bottom surface of the shielding cover plate 2.

[0046] In this embodiment, the transmission line 3 is a 50-ohm transmission line for microwave signal transmission, used to realize the transmission of microwave signals. The types of the transmission line 3 include microstrip line, stripline, and coplanar waveguide.

[0047] Combined with Figure 2 As shown in the figure, through holes 102 are respectively opened at the left and right ends of the shielding housing 1 for installing SMA connectors for performance testing.

[0048] Combined with Figure 4As shown, the transmission belt line 3 includes a dielectric substrate 302 and a conductive strip 301 disposed on the dielectric substrate 302; the dielectric substrate 302 is connected to the inner cavity bottom wall of the shielding housing 1 by means of screw assembly, or bonding, or sintering, or welding.

[0049] Combined with Figure 1 As shown, after the shielding cover plate 2 is installed on the shielding housing 1, a shielding cavity is formed. The connection method between the shielding cover plate 2 and the shielding housing 1 can be screw assembly, laser sealing welding, bonding, sintering, welding, etc. After the shielding cover plate 2 covers the shielding housing 1, a closed housing wrapping the transmission belt line 30 is formed.

[0050] Embodiment 2:

[0051] Combined with Figures 5 to 7 As shown, based on the above Embodiment 1, the difference between this Embodiment 2 and Embodiment 1 lies in the different shapes of the bumps 201.

[0052] Specifically, in this Embodiment 2, n-level steps are integrally formed on the left and right sides of the bump 201, where n is a positive integer. In terms of the implementation effect, the more the number of steps, the better the suppression effect, and the number of steps can be set according to actual needs. And the number and position of the bumps 201 can be set according to the specific position, as long as the bumps 201 are disposed in the inner cavity of the shielding housing 1. If possible, the physical position of the bumps 201 on the bottom surface of the shielding cover plate 2 and the number of bumps 201 placed can be designed according to the actual engineering structure and requirements.

[0053] For the convenience of explanation, steps are provided on the left and right sides of the bump 201, so that after the bump 201 forms a stepped structure, it has a good effect on suppressing the resonance of the shielding cavity. For this reason, combined with Figures 5 to 7 As described, there is a 1-level step on the left and right sides of the bump 201.

[0054] Specifically, the shielding cover plate 2 is machined from an aluminum alloy material, and bumps 201 with 1-level steps on both sides are integrally formed on the bottom surface of the shielding cover plate 2. The bumps 201 are located at the center position of the bottom surface of the shielding cover plate 2, and the long direction of the bumps 201 is perpendicular to the long direction of the shielding cover plate 2.

[0055] The length C of the bump 201 is 12 mm, the width E of the bump 201 is 8.6 mm, the total height B of the bump 201 relative to the bottom surface of the shielding cover plate 2 is 6 mm; the height A of the steps on the left and right sides of the bump 201 is 3 mm; after setting one-level steps, the width D of the convex platform on the bottom surface of the bump 201 is 5 mm.

[0056] After setting a first - level step on the left and right sides of the bump 201, the entire bump 201 forms a first - level stepped surface F1 and a second - level stepped surface F2 relative to the bottom surface of the shielding cover plate 2. Therefore, the cross - section of the entire bump 201 is an inverted "convex" shape.

[0057] In addition, in the second embodiment, the shielding housing 1 is machined from an aluminum alloy material. The external dimensions of the shielding housing 1 are 68 mm in length, 20 mm in width, and 16 mm in height, and the dimensions of the accommodation cavity 101 are 60 mm in length, 12 mm in width, and 10 mm in height. Through - holes 102 are respectively opened at both the left and right ends of the shielding housing 1 for installing SMA connectors for performance testing.

[0058] Comparative example:

[0059] The difference between the comparative example and the second embodiment is that in the comparative example, the shielding cover plate 2 is a flat - plate structure, that is, no bump 201 is provided at the bottom of the shielding cover plate 2. While in the second embodiment, a bump 201 is provided on the bottom surface of the shielding cover plate 2, and a first - level step is provided on the left and right sides of the bump 201. The structures of the remaining shielding housing 1 and the transmission belt line 3 are exactly the same as those in the second embodiment.

[0060] By using the comparative example and the second embodiment for comparison of transmission performance tests, specifically as Figure 8 、 Figure 9 shown.

[0061] Among them Figure 8 is the transmission performance diagram when no bump is provided at the bottom surface of the shielding cover plate 2 in the comparative example; Figure 9 is the transmission performance diagram when a bump 201 with a first - level step is provided at the bottom surface of the shielding cover plate 2 in the second embodiment.

[0062] The purpose of the shielding housing 1 and the transmission belt line 3 is to construct a shielding cavity with an internal transmission belt line 3, and then the shielding cover plate 2 is installed on the shielding housing 1. If there is no stepped - structure bump 201 on the shielding cover plate 2, a cavity with an internal transmission belt line is formed. According to the resonant cavity theory, this cavity will generate a resonant frequency when the belt line transmits signals. If the resonant frequency overlaps with the working frequency band, it will affect the transmission performance of the belt line. However, by adopting the second embodiment, steps are provided on both sides of the bump 201 of the shielding cover plate 2, forming a stepped structure, thus forming a closed cavity with an internal transmission belt line 3 and a stepped structure. The introduction of this stepped structure will reduce or even eliminate the influence of cavity resonance on the performance of the transmission belt line. Combining Figure 8 and Figure 9 shown, it can be seen that after applying the stepped structure, the echo loss due to the discontinuous protrusion caused by resonance is suppressed, and it has good cavity resonance suppression performance.

[0063] In a possible implementation manner, the shielding housing 1 is not limited to Figure 2The single structure shown may depend on the overall structure of the product in actual engineering applications. It should be understood that as long as the shielding housing 1 that forms the wrapped transmission belt line 3 belongs to the scope described in the present invention.

[0064] In a possible implementation, the shielding cover plate 2 is not limited to Figure 3 , Figure 5 the single structure shown. In actual engineering applications, it may depend on the overall structure of the product. It should be understood that as long as there is a bump 201 structure proposed in the present invention on the shielding cover plate 2, or there is a stepped structure formed by steps on both sides of the bump 201 and used for suppressing the cavity resonance of the transmission belt line and improving the performance of the transmission belt line, it belongs to the scope described in the present invention.

[0065] In a possible implementation, the transmission belt line 3 is a 50-ohm transmission belt line for microwave signal transmission, used to achieve the transmission of microwave signals, and is not limited to Figure 4 the microstrip line structure shown. In actual engineering applications, it may be adjusted according to the transmission performance requirements of the product. It should be understood that as long as it is a belt line structure for signal transmission, such as microstrip lines, striplines, coplanar waveguides, etc., they all belong to the scope described in the present invention.

[0066] The above are only the preferred embodiments of the present invention, and do not limit the patent scope of the present invention. All equivalent structural transformations made under the inventive concept of the present invention by using the content of the specification and drawings of the present invention, or directly / indirectly applied in other related technical fields are included in the patent protection scope of the present invention.

Claims

1. A stepped transmission strip line shielding cavity resonance suppression structure, characterized in that: include: A shielding shell (1), the shielding shell (1) comprising an open accommodating cavity (101); A transmission line (3) is installed in the accommodating cavity (101) of the shielding shell (1); A shielding cover plate (2) is used to cover the shielding shell (1), and a protrusion (201) is integrally formed on the lower surface of the shielding cover plate (2).

2. A stepped transmission strip line shielding cavity resonance suppression structure as claimed in claim 1, characterized in that: The shielding shell (1) and the shielding cover plate (2) are both made of materials having electromagnetic shielding function.

3. The stepped transmission strip line shielding cavity resonance suppression structure according to claim 1, characterized in that: The shielding shell (1) and the shielding cover plate (2) are both made of aluminum alloy.

4. The stepped transmission strip line shielding cavity resonance suppression structure according to claim 1, characterized in that: The convex block (201) is in the shape of a rectangular parallelepiped.

5. The stepped transmission strip line shielding cavity resonance suppression structure according to claim 1, characterized in that: The left and right side surfaces of the protrusion (201) are integrally formed with n steps, where n is a positive integer.

6. A stepped transmission strip line shielding cavity resonance suppression structure as claimed in claim 5, characterized in that: The number of steps on the left and right sides of the protrusion (201) is one.

7. The stepped transmission strip line shielding cavity resonance suppression structure according to claim 1, characterized in that: The transmission strip line (3) is a 50 ohm transmission strip line for microwave signal transmission.

8. The stepped transmission strip line shielding cavity resonance suppression structure according to claim 1, characterized in that: The types of the transmission strip line (3) include microstrip line, strip line and coplanar waveguide.

9. The stepped transmission strip line shielding cavity resonance suppression structure according to claim 1, characterized in that: Through holes (102) are respectively provided at the left and right ends of the shielding shell (1) for installing SMA connectors for performance testing.

10. The stepped transmission strip line shielding cavity resonance suppression structure according to claim 1, characterized in that: The transmission strip line (3) comprises a dielectric substrate (302) and a conductive strip (301) arranged on the dielectric substrate (302); the dielectric substrate (302) is connected to the bottom wall of the inner cavity of the shielding shell (1) by means of screw assembly, bonding, sintering or welding.

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