A device for improving cavity isolation and T / R assembly

Abstract

The present invention discloses a device for improving the isolation of a cavity and a T / R assembly, comprising a shell and a cover plate installed on the top thereof, a partition rib for isolating the cavity inside the shell provided inside the shell, and an elastic spring installed at the bottom of the cover plate and clamping the partition rib, a base plate provided inside the shell and below the partition rib; the partition rib and the elastic spring separate the interior of the shell into two independent cavities. This application designs an elastic spring between the partition rib and the cover plate, and utilizes the elastic deformation of the elastic spring itself to ensure good contact with the partition rib, providing a larger free space for the allowable range of the gap between the partition rib and the cover plate, eliminating the problem of non-closure of the shielding circuit due to the gap between the partition rib and the cover plate, thereby effectively improving the isolation between the cavities; the elastic spring has a high relaxation resistance, and can restore its elastic deformation when unplugged from the partition rib, solving the problem of repeated plugging and unplugging.

Description

Technical Field

[0001] The present invention relates to the technical field of microwave transmit / receive modules (T / R modules), and in particular to a device for improving cavity isolation and a T / R module. Background Art

[0002] The T / R assembly is the most widely installed core component in active phased array radars. It contains multiple bare chips for RF, control, and power management, all housed in an airtight metal or ceramic package. The T / R assembly's transmit and receive RF links typically include two or more amplifier stages. To avoid electromagnetic compatibility issues such as poor isolation and self-oscillation caused by spatial coupling and crosstalk between the upstream and downstream amplifiers, the package design typically employs a separate cavity design, placing the upstream and downstream amplifiers in different cavities.

[0003] Another situation is that multi-channel T / R modules often isolate each channel in a cavity. One solution is to adopt the two-layer circuit structure proposed by Zhang Shengchun et al. in "Development of High-Isolation Millimeter-Wave Frequency-Converting Transceiver Components." This structure distributes the microwave circuits in the front cavities, while the signal interconnects and power modulation are located on the back of the module. While this approach achieves a certain degree of cavity isolation, it also increases the thickness of the module and is not suitable for the backside heat dissipation requirements of high-power T / R modules.

[0004] To meet the integration, miniaturization, and high-power heat dissipation requirements of T / R components, external control and power interfaces are typically shared by pre- and post-amplifiers or multiple channels. This requires that the substrate, which interconnects these signals, cannot be separated from the cavity. Therefore, the specific measure for cavity separation design is to bond or weld a rib to the substrate to form a cavity with the T / R component shell and cover. Because the shell, substrate, rib, and cover all have certain machining tolerances in the height direction, a gap is inevitably present between the rib and the cover. This gap can seriously affect the isolation between the two cavities.

[0005] In order to improve the isolation between cavities, the commonly used measure in current engineering is to design two raised forks on the cover 2' of the T / R assembly, and the partition rib 4' is embedded in the middle of the two forks. The bottom of the partition rib 4' is the base plate 3', and the base plate 3' is installed in the bottom shell 1'. Figure 1 and Figure 2 As shown; due to the machining tolerances of the fingers on the cover plate 2', the spacer 4' and their relative installation positions, the fingers on the cover plate 2' and the spacer 4' will also have a nominal gap in the horizontal direction l 1 and l 2, l 1 and l2 is generally around 0.1mm~0.3mm. This design essentially only changes the path length of electromagnetic waves propagating along the gap, improving the isolation at a specific frequency but cannot meet the requirements of high isolation between broadband T / R component cavities.

[0006] Figure 3 The isolation simulation results of the structure using full-wave electromagnetic simulation software are given. In the figure, the horizontal axis represents the frequency in GHz, covering from 0.01GHz to 40GHz; the vertical axis represents the isolation in dB, and the middle curve represents the isolation value corresponding to each frequency point; the simulation results quantitatively confirm the above conclusions: when the gap g between the cover plate 2' and the partition rib 4' takes a typical value of 0.2mm and l 1. l 2 are also set to the commonly used engineering size of 0.2mm. There are many strong coupling frequencies in the frequency band of 0.01GHz~40GHz, and the worst isolation is only about -5dB. Normal engineering application requirements are generally between -40dB and -35dB. The above technology is far from meeting the engineering application requirements. Summary of the Invention

[0007] The technical problem to be solved by the present invention is: how to improve the isolation between different cavities of a T / R assembly.

[0008] In order to solve the above technical problems, the present invention provides the following technical solutions:

[0009] A device for improving cavity isolation, comprising a housing and a cover mounted on top thereof, wherein the housing is provided with partition ribs for isolating the cavity within the housing, and further comprising an elastic spring mounted on the bottom of the cover and clamping the partition ribs, and a base plate is provided inside the housing and below the partition ribs;

[0010] The partition ribs and the elastic spring separate the interior of the shell into two independent cavities. The partition ribs, the elastic spring and the shell, the base plate and the cover plate in contact therewith form a complete and continuous shielding loop.

[0011] The present application designs an elastic spring between the partition rib and the cover plate, and utilizes the elastic deformation of the elastic spring itself to ensure good contact with the partition rib, providing a larger free space for the allowable range of the gap between the partition rib and the cover plate, eliminating the problem of the shielding circuit not being closed due to the gap between the partition rib and the cover plate, thereby effectively improving the isolation between the cavities; the elastic spring has a high relaxation resistance, and can restore the elastic deformation when pulled out from the partition rib, solving the problem of repeated plugging and unplugging. The elastic contact between the elastic spring and the cover plate rather than rigid crimping is conducive to the release of thermal stress caused by different thermal expansion coefficients of the shell, substrate, partition rib, cover plate, etc., and has the characteristics of high reliability.

[0012] As a further solution of the present invention, one or more rows of metallized through holes are provided inside the substrate directly below the locations of the partition ribs.

[0013] As a further solution of the present invention: the elastic spring includes a symmetrically distributed left part and a right part of the spring, wherein the left part of the spring and the right part of the spring are designed as an integral whole, and the left part of the spring and the right part of the spring are both in an "Ω" shape, and a clamping gap is left between the left part of the spring and the right part of the spring for clamping the partition rib, and the horizontal sides of the left part of the spring and the right part of the spring are welded to the cover plate through a welding piece assembly.

[0014] As a further solution of the present invention: the elastic spring includes an integrated clamping portion, a bending portion and a connecting portion, the connecting portion is a horizontal plane and is welded to the cover plate through a welding piece assembly, and both ends of the connecting portion are simultaneously inclined toward the middle to form a clamping portion for clamping the partition rib, and one end of the two clamping portions is simultaneously bent outward away from the partition rib to form a bending portion.

[0015] As a further solution of the present invention: the thickness t of the elastic spring is 0.08 mm, 0.1 mm, 0.12 mm or 0.15 mm.

[0016] As a further solution of the present invention: the initial spacing d of the elastic spring used to clamp the partition ribs is smaller than the width w of the partition ribs, and the difference between w and d is between 0.15 mm and 0.3 mm.

[0017] As a further solution of the present invention: the height h of the elastic spring is greater than the height g of the gap between the partition rib and the cover plate, and the difference between h and g is greater than 1.5 mm.

[0018] As a further solution of the present invention: the soldering piece assembly is made of lead-tin or solder with a lower melting point; and the elastic spring is made of beryllium bronze material.

[0019] As a further solution of the present invention: the shell, cover plate and partition ribs are all made of metal or alloy materials.

[0020] The invention also discloses a T / R assembly, including a device for improving cavity isolation.

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] The present application designs an elastic spring between the partition rib and the cover plate, and utilizes the elastic deformation of the elastic spring itself to ensure good contact with the partition rib, providing a larger free space for the allowable range of the gap between the partition rib and the cover plate, eliminating the problem of non-closure of the shielding circuit due to the gap between the partition rib and the cover plate, thereby effectively improving the isolation between the cavities; the elastic spring has a high relaxation resistance, and can restore the elastic deformation when pulled out from the partition rib, solving the problem of repeated plugging and unplugging. The elastic contact between the elastic spring and the cover plate rather than rigid crimping is conducive to the release of thermal stress caused by different thermal expansion coefficients of the shell, substrate, partition rib, cover plate, etc., and has the characteristic of high reliability. The present invention fundamentally solves the electromagnetic compatibility problems such as mutual coupling and crosstalk between cavities, and has extremely high practical significance and application value.

[0023] This application designs two elastic springs of different shapes, wherein the elastic spring can adopt a double "Ω" type structure, and the structure is modeled and the isolation simulation is performed using full-wave electromagnetic simulation software. Figure 6 The simulation results show that: under certain parameters of g, w, d, and h, the worst isolation in the frequency range of 0.01GHz to 40GHz is below -50dB, which is better than the requirements of engineering applications. The elastic spring can also be used as follows: Figure 8 The inverted hanger-like structure shown in the figure has a worst-case isolation of less than -47 dB in the frequency band of 0.01 GHz to 40 GHz under certain parameter conditions of g, w, d, and h, which can still meet the requirements of engineering applications. Therefore, the shape of the elastic spring 5 can be selected according to the actual application scenario. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 This is a cross-sectional view of the interdigitated structure of the gap between the reinforcement and the cover plate commonly used in current projects;

[0025] Figure 2 for Figure 1 A partial enlargement of area A and the size parameter identification diagram;

[0026] Figure 3 This is the isolation simulation result diagram of the interdigital structure of gaps between reinforcement and cover plates commonly used in current projects;

[0027] Figure 4 This is a cross-sectional view of Example 1 of the present invention, in which the partition rib and the cover plate are in elastic contact using double "Ω"-shaped elastic springs;

[0028] Figure 5 For the present invention Figure 4 A partial enlargement of area B and a diagram showing size parameters;

[0029] Figure 6This is a diagram showing the isolation simulation results of Example 1 of the present invention, in which the partition rib and the cover plate adopt elastic contact with double "Ω"-shaped elastic springs;

[0030] Figure 7 This is a cross-sectional view of Example 2 of the present invention, in which the partition rib and the cover plate are in elastic contact using an elastic spring having an inverted hanger-like structure;

[0031] Figure 8 For the present invention Figure 7 A partial enlargement of the C area and the size parameter identification diagram;

[0032] Figure 9 This is a diagram showing the results of the isolation simulation of Example 2 of the present invention, in which the partition rib and the cover plate adopt elastic contact with an elastic spring having an inverted hanger-like structure;

[0033] Description of reference numerals:

[0034] 1. Shell; 2. Cover; 21. Mounting slot; 3. Base plate; 4. Partition ribs;

[0035] 5. Elastic spring; 511. Left part of spring; 512. Right part of spring; 521. Clamping part; 522. Bending part; 523. Connecting part;

[0036] 6. Soldering lug assembly; 611. Soldering lug one; 612. Soldering lug two; 613. Soldering lug three; 621. Soldering lug four. DETAILED DESCRIPTION

[0037] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0038] Example 1

[0039] Reference Figure 4 and Figure 5, a device for improving cavity isolation, including a shell 1, a cover plate 2, a substrate 3, a partition rib 4, an elastic spring 5 and a welding piece assembly 6, the substrate 3 is welded to the shell 1, and a partition rib 4 for isolating the inner cavity of the shell is arranged above the substrate 3 inside the shell 1, the cover plate 2 and the shell 1 are welded together by laser sealing or parallel sealing process to provide the airtight environment required for the bare chip; the partition rib 4 is bonded to the substrate 3 with conductive glue or solder; the elastic spring 5 is welded to the mounting groove 21 on the side of the cover plate 2 facing the shell 1 through the welding piece assembly 6; and the shell 1, cover plate 2, substrate 3, partition rib 4 and elastic spring 5 together separate the interior of the T / R component into two independent cavities.

[0040] Reference Figure 4 and Figure 5 A row of plated through holes 31 is provided within the substrate 3, directly below the spacer ribs 4. To further enhance shielding effectiveness, additional rows of plated through holes 31 can be added to the left and right sides of this row of plated through holes 31, arranged in staggered positions. It should be noted that the housing 1, cover 2, spacer ribs 4, spring 5, and plated through holes 31 within the substrate 3 form a complete and continuous shielding loop.

[0041] Reference Figure 4 and Figure 5 The elastic reed 5 adopts an inverted double "Ω" shape and can be stamped by a special mold.

[0042] Furthermore, the elastic spring 5 includes a symmetrically distributed left spring portion 511 and a right spring portion 512, wherein the left spring portion 511 and the right spring portion 512 are designed as an integral whole, and the left spring portion 511 and the right spring portion 512 are both in an inverted "Ω" shape. A clamping gap is left between the left spring portion 511 and the right spring portion 512 for clamping the partition 4, and the horizontal surfaces of the left spring portion 511 and the right spring portion 512 are both welded to the cover plate 2 through the welding piece assembly 6.

[0043] Furthermore, the thickness t of the elastic spring 5 can be selected from specifications of 0.08mm, 0.1mm, 0.12mm, and 0.15mm; it is not advisable to select thicker specifications, which will result in the elastic spring 5 and the partition rib 4 being inserted and separated with greater force and easily damaging the coating of the elastic spring 5 and the partition rib 4. This application does not limit the thickness of the elastic spring 5, but only gives several preferred implementation methods for reference, rather than limiting it.

[0044] Furthermore, the elastic spring 5 is made of beryllium bronze material, and after being formed, it can be heat-treated in a hot vacuum furnace to obtain the required rigidity and elasticity.

[0045] Furthermore, the initial spacing d in the elastic spring 5 for clamping the partition 4 is smaller than the width w of the partition 4. In this embodiment 1, d is the spacing between the left part 511 of the spring and the right part 512 of the spring, and the difference between w and d is between 0.15 mm and 0.3 mm.

[0046] Furthermore, the height h of the elastic spring 5 is greater than the height g of the gap between the partition rib 4 and the cover plate 2 , and the difference between h and g should be greater than 1.5 mm.

[0047] Reference Figure 5 In this embodiment 1, the soldering piece assembly 6 is divided into a soldering piece 1 611, a soldering piece 2 612, and a soldering piece 3 613 according to the contact surface between the elastic spring piece 5 and the cover plate 2. Among them, the soldering piece 1 611, the soldering piece 2 612, and the soldering piece 3 613 are preferably made of lead-tin or a solder with a lower melting point to prevent the elastic spring piece 5 from annealing and losing its elasticity due to excessively high soldering temperature.

[0048] Reference Figure 4 and Figure 5 During the sealing process, the cover plate 2 with the elastic spring 5 welded is buckled on the housing 1 with the elastic spring 5 facing the partition rib 4, and the partition rib 4 is inserted into the elastic spring 5. The left part 511 and the right part 512 of the elastic spring 5 are opened outward and elastically contact with the partition rib 4.

[0049] As a preferred embodiment of the present invention, the housing 1, the cover plate 2, and the ribs 4 are all made of metal or alloy materials that are good conductors and suitable for airtight packaging, such as aluminum, Kovar, titanium alloy, etc.

[0050] Reference Figure 4 In this embodiment 1, the cover plate 2, elastic spring 5, ribs 4, metallized through-holes 31 in the substrate 3, and the housing 1 form a complete and continuous shielding loop from top to bottom. This structure was modeled and the isolation simulation was performed using full-wave electromagnetic simulation software.

[0051] See Figure 6 The simulation results show that when g is 0.4mm, w is 1mm, d is 0.8mm, and h is 1.9mm, the worst isolation in the 0.01GHz to 40GHz frequency band is below -50dB. Figure 6 The horizontal axis represents the frequency in GHz, covering from 0.01GHz to 40GHz; the vertical axis represents the isolation in dB, and the middle curve represents the isolation value corresponding to each frequency point. For example, the worst m1 identification point indicates that the cavity isolation value at 23.0042GHz is -50.9648dB; normal engineering application requirements are generally between -40dB and -35dB, and this embodiment 1 is already better than the engineering application requirements.

[0052] Example 2

[0053] Reference Figure 7 and Figure 8 The other aspects of the embodiment 2 are the same as those of the embodiment 1, except for the shape of the elastic spring 5 and the number of welding areas with the cover plate 2.

[0054] Furthermore, the elastic spring 5 includes an integrally designed clamping portion 521, a bending portion 522 and a connecting portion 523. The connecting portion 523 is in a horizontal plane and is welded to the cover plate 2 through a welding piece 621. Both ends of the connecting portion 523 are simultaneously inclined toward the middle to form a clamping portion 521 for clamping the partition 4. One end of the two clamping portions 521 is simultaneously bent outward away from the partition 4 to form a bending portion 522. Only one welding is required between the elastic spring 5 and the cover plate 2 in this embodiment. Since the left arm and the right arm of the elastic spring 5 are in a free state, that is, the two bending portions 522, the force for inserting and separating the elastic spring 5 and the partition 4 is slightly smaller than that in Example 1.

[0055] See Figure 9 The structure was modeled and the isolation was simulated using full-wave electromagnetic simulation software. The same parameters as those in Example 1, g, w, d, and h, were used. That is, under the conditions of g being 0.4 mm, w being 1 mm, d being 0.8 mm, and h being 1.9 mm, the simulation results showed that the worst isolation within the frequency range of 0.01 GHz to 40 GHz also reached below -47 dB. Figure 9 The horizontal axis represents frequency in GHz, covering the range from 0.01 GHz to 40 GHz. The vertical axis represents isolation in dB. The middle curve represents the isolation values ​​corresponding to each frequency point. For example, the worst point m1 indicates a cavity isolation value of -47.4489 dB at 36.4009 GHz. Although slightly worse than Example 1 by 3 dB, it still meets the requirements of engineering applications. The shape of the elastic reed 5 of Example 1 or Example 2 can be selected according to the actual application scenario.

[0056] Example 3

[0057] This embodiment 3 provides a T / R assembly, which adopts the structure of improving cavity isolation of embodiment 1 or embodiment 2.

[0058] The present invention designs an elastic spring 5 between the partition rib 4 and the cover plate 2, and utilizes the elastic deformation of the elastic spring 5 itself to ensure good contact with the partition rib 4, which can not only avoid putting forward stringent requirements on the design of the gap between the partition rib 4 and the cover plate 2, but also eliminate the problem of non-closure of the shielding circuit due to the existence of the gap, thereby greatly improving the isolation between the cavities; the elastic spring 5 has a high relaxation resistance, and can restore the elastic deformation when pulled out from the partition rib 4, so as to adapt to the actual application of repeated plugging and unplugging; the elastic contact between the elastic spring 5 and the cover plate 2 rather than the rigid crimping is conducive to the release of thermal stress caused by different thermal expansion coefficients of the shell 1, substrate 3, partition rib 4, cover plate 2, etc., and has the characteristic of high reliability.

[0059] Full-wave electromagnetic simulation software results from both examples demonstrate excellent isolation across the 0.01GHz to 40GHz frequency range, making this technology suitable for broadband T / R components requiring high isolation in pre- and post-amplifier cavity separation or multi-channel cavity separation. This invention fundamentally addresses electromagnetic compatibility issues such as coupling and crosstalk between cavities, demonstrating its high practical significance and application value.

[0060] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A device for improving cavity isolation, comprising a housing (1) and a cover plate (2) mounted on the top thereof, wherein a partition rib (4) for isolating the cavity inside the housing is provided inside the housing (1), characterized in that: It also includes an elastic spring (5) installed at the bottom of the cover plate (2) and clamping the partition rib (4), and a base plate (3) is provided inside the housing (1) and below the partition rib (4); The partition rib (4) and the elastic spring (5) separate the interior of the housing (1) into two independent cavities, and the partition rib (4), the elastic spring (5) and the housing (1), the base plate (3) and the cover plate (2) in contact therewith form a complete and continuous shielding circuit; The elastic spring (5) includes a symmetrically distributed left spring portion (511) and a right spring portion (512), wherein the left spring portion (511) and the right spring portion (512) are designed as an integral body, and both the left spring portion (511) and the right spring portion (512) are in an "Ω" shape. A clamping gap for clamping the partition rib (4) is left between the left spring portion (511) and the right spring portion (512), and the horizontal sides of the left spring portion (511) and the right spring portion (512) are welded to the cover plate (2) through a welding piece assembly (6).

2. The device for improving cavity isolation according to claim 1, characterized in that: One or more rows of metallized through holes (31) are provided inside the substrate (3) along the interior directly below the location of the partition ribs (4).

3. The device for improving cavity isolation according to claim 1, characterized in that: The thickness t of the elastic spring (5) is 0.08 mm, 0.1 mm, 0.12 mm, or 0.15 mm.

4. The device for improving cavity isolation according to claim 1, characterized in that: The initial spacing d of the elastic spring (5) used to clamp the partition rib (4) is smaller than the width w of the partition rib (4), and the difference between w and d is between 0.15 mm and 0.3 mm.

5. The device for improving cavity isolation according to claim 1, characterized in that: The height h of the elastic spring (5) is greater than the height g of the gap between the partition rib (4) and the cover plate (2), and the difference between h and g is greater than 1.5 mm.

6. The device for improving cavity isolation according to claim 1, characterized in that: The soldering piece assembly (6) uses lead-tin or solder with a lower melting point.

7. The device for improving cavity isolation according to claim 1, characterized in that: The elastic spring (5) is made of beryllium bronze.

8. The device for improving cavity isolation according to claim 1, characterized in that: The shell (1), cover plate (2), and partition ribs (4) are all made of metal.

9. The device for improving cavity isolation according to claim 1, characterized in that: The shell (1), cover plate (2), and partition ribs (4) are all made of alloy material.

10. A T / R assembly, characterized in that: The device comprises the device for improving cavity isolation as described in any one of claims 1 to 9.

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