An attenuation chip and a coaxial attenuator

Abstract

This utility model discloses an attenuation chip and a coaxial attenuator, belonging to the field of microwave technology. It achieves mechanical positioning and fixation between the attenuation chip and the contact cap by setting a notch at the edge of a ceramic substrate and inserting it into a grooved contact cap, avoiding the problem of easy failure of conductive adhesive or soldering, and improving connection reliability and lifespan. The bottom wall of the notch can be fitted with a positioning recess and a positioning protrusion in the groove to enhance positioning stability. The bottom wall of the notch also has a metal conductive layer that is electrically connected to the microstrip line, ensuring a stable electrical path. The metal conductive layer consists of a sputtered thin film layer and an electroplated layer, and the adhesion is enhanced by the pit structure. The ceramic substrate is preferably aluminum nitride, and the microstrip line serves as the input and output connection parts. The coaxial attenuator is assembled with the attenuation chip through a housing, pins, and a contact cap, using elastic clamping to achieve radial and axial positioning, resulting in high assembly efficiency. Through size optimization, frequency performance can be improved to 44GHz.

Description

Technical Field

[0001] This utility model relates to the field of microwave technology, specifically to an attenuation chip and a coaxial attenuator. Background Technology

[0002] Coaxial attenuators are energy-loss type RF / microwave components, a type of passive microwave device, mainly used in fields such as communication, radar, and test and measurement to achieve signal power control.

[0003] Existing coaxial attenuators typically consist of two parts: a coaxial connector and an attenuation chip. Structurally, the input contact cap and output contact cap clamp the two ends of the attenuation chip, respectively, and are fixed by clamping plates. Specifically, the input microstrip line end of the attenuation chip is generally fixed in the groove at the tail end of the input contact cap by means of conductive adhesive bonding or welding; the output microstrip line end of the attenuation chip is fixed in the groove at the head end of the output contact cap in the same way, thereby forming an electrical connection.

[0004] However, this type of connection has certain reliability issues during long-term use. On the one hand, conductive adhesive or solder joints are prone to detachment or failure under thermal cycling, vibration and environmental stress. On the other hand, during assembly and use, the axial and radial stresses acting on the attenuation chip may cause the pads to crack or the attenuation chip to crack, which in turn causes unstable electrical connections and affects the overall performance and lifespan of the device. Utility Model Content

[0005] The purpose of this invention is to provide an attenuation chip and a coaxial attenuator. By setting a notch at the edge of a ceramic substrate and engaging it with a grooved contact cap, the attenuation chip and the contact cap are mechanically positioned. This solves the technical problem in the prior art that relies on conductive adhesive or welding for fixing, which is prone to detachment, failure, or chip cracking due to thermal cycling, vibration, and environmental stress. This invention has the beneficial effects of improving connection reliability, enhancing device durability, and improving overall performance.

[0006] To achieve the aforementioned objectives, the technical solution adopted by this utility model is as follows:

[0007] Two microstrip lines are respectively disposed on the left and right edges of the front side of the ceramic substrate, forming the connection part of the attenuation chip for input or output signals;

[0008] The outer side of the connection part of the attenuation chip is provided with a through groove-shaped notch, and the extension direction of the bottom wall of the notch is perpendicular to the front side of the ceramic substrate.

[0009] When the contact cap with the groove is inserted into the notch, the bottom wall of the groove abuts against the bottom wall of the notch, and the steps on the upper and lower sides of the notch cooperate with the two sides of the groove base to limit the contact cap.

[0010] Preferably, the bottom wall of the notch is provided with a positioning recess for insertion and fixing with the positioning protrusion corresponding to the bottom wall of the groove.

[0011] Preferably, a metal conductive layer is provided on the bottom wall of the notch, and the metal conductive layer is electrically connected to the microstrip line;

[0012] When the contact cap is inserted into the attenuation chip, the metal conductive layer abuts against the bottom wall of the groove.

[0013] Preferably, the conductive metal layer includes a metal thin film layer and an electroplated layer, wherein the metal thin film layer is sputtered onto the bottom wall of the notch, and the electroplated layer covers the metal thin film layer.

[0014] Preferably, the bottom wall of the notch has several pits to enhance the bonding strength between the metal conductive layer and the ceramic substrate.

[0015] Preferably, the ceramic substrate is rectangular, and the microstrip line on the front side of the ceramic substrate includes an input microstrip line and an output microstrip line, which are spaced apart and disposed in the middle of the left and right edges of the front side of the ceramic substrate.

[0016] The ceramic substrate is also provided with a first grounding device and a second grounding device on the front side. The first grounding device and the second grounding device are arranged at intervals on the upper and lower sides of the front side of the ceramic substrate and extend along the left and right direction of the ceramic substrate.

[0017] Preferably, the ceramic substrate is made of aluminum nitride.

[0018] A coaxial attenuator includes a housing, an input pin, an output pin, an input contact cap, an output contact cap, and an attenuation chip with notches on the outer sides of both the aforementioned input and output connection portions;

[0019] The housing has an input connector at the front end and an output connector at the rear end. The input pin and the output pin are coaxially arranged in the input connector and the output connector, respectively.

[0020] The first end of the input contact cap is coaxially and elastically connected to the inner hole of the tail end of the input pin, and the tail end of the output contact cap is coaxially and elastically connected to the inner hole of the first end of the output pin.

[0021] The input contact cap has a groove at its tail end and the output contact cap has a notch at its head end, which is inserted into the notch of the input connection part and the output connection part of the attenuation chip respectively, and the attenuation chip is radially positioned.

[0022] The input and output pins clamp the attenuation chip on both sides under the action of elastic force, and position the attenuation chip axially.

[0023] Preferably, the input pin has a socket assembly on its shaft, a pin is connected to the head of the shaft, and an inner hole is opened at the tail end of the shaft;

[0024] The diameter at the joint between the rod and the socket assembly is 0.8mm, and the diameter of the rest is 1.27mm; the thickness of the attenuation chip is 1.04mm.

[0025] Preferably, the bottom wall of the notch of the input connector is provided with a positioning recess, and the bottom wall of the groove of the input contact cap is provided with a corresponding positioning protrusion;

[0026] And / or, a positioning recess is provided on the bottom wall of the notch of the output connection part, and a corresponding positioning protrusion is provided on the bottom wall of the groove of the output contact cap.

[0027] The beneficial effects of this utility model are as follows:

[0028] 1. Improved connection reliability: This utility model has a notch at the edge of the ceramic substrate, and achieves mechanical limiting and fixing through the groove of the contact cap;

[0029] Compared to existing methods that rely on conductive adhesive or soldering, this solution avoids problems such as adhesive aging or solder joint cracking caused by thermal cycling, vibration, and humid environments, significantly improving the connection reliability between the attenuation chip and the contact cap and extending the device lifespan.

[0030] 2. Improved electrical connection stability: This invention provides a metal conductive layer on the bottom wall of the notch and connects it to the microstrip line, so that the bottom wall of the contact cap groove is in direct contact with the conductive layer of the chip, forming a stable and reliable electrical path;

[0031] The metal thin film layer is formed by sputtering, which can enhance the bonding ability between the electroplated layer and the ceramic substrate and prevent the conductive layer from peeling off due to thermal cycling. The electroplated layer covers the metal thin film layer, which not only improves the conductivity but also enhances the overall structural strength, so that the chip can maintain stable electrical conduction under mechanical clamping, thereby ensuring the consistency of high-frequency signal transmission.

[0032] 3. Improved assembly efficiency: This utility model adopts an elastic clamping technology, which eliminates the traditional welding or conductive adhesive coating process;

[0033] The assembly process is simple and quick, significantly improving production efficiency. It also avoids inconsistencies caused by manual welding or gluing, which is conducive to large-scale production.

[0034] 4. The chip is securely clamped: the positioning recess on the bottom wall of the notch and the positioning protrusion on the bottom wall of the groove engage with each other to prevent relative slippage between the chip and the contact cap;

[0035] This structure not only enhances clamping stability but also enables self-positioning during assembly, improving positioning accuracy and thus ensuring the stability and consistency of the signal path. Furthermore, it reduces the stress on the steps on the upper and lower sides of the notch, increasing the durability of the attenuation chip.

[0036] 5. Frequency and power performance optimization: Through the rational design of the input pin body diameter (0.8mm at the socket assembly mating point, and 1.27mm for the rest) and the attenuation chip thickness (1.04mm), the coaxial attenuator can effectively increase the operating frequency to 44GHz while maintaining the original power capacity, thus expanding the application range of the device. Attached Figure Description

[0037] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0038] Figure 1 This is a schematic diagram of the attenuation chip in this application;

[0039] Figure 2 for Figure 1 A schematic diagram of one side of the structure;

[0040] Figure 3 This is a schematic diagram of the contact cap structure in this application;

[0041] Figure 4 for Figure 3 A schematic diagram of the structure from the perspective of A;

[0042] Figure 5 This is a schematic diagram of the coaxial attenuator in this application;

[0043] Figure 6 for Figure 5 Cross-sectional view.

[0044] Among them, 1-ceramic substrate, 2-notch, 3-groove, 5-step, 6-positioning recess, 7-positioning protrusion, 8-metal conductive layer, 11-input microstrip line, 12-output microstrip line, 13-housing, 14-input pin, 15-output pin, 16-input contact cap, 17-output contact cap, 18-input connector, 19-output connector, 22-jack assembly, 23-pin. Detailed Implementation

[0045] In the description of this utility model, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this utility model and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model.

[0046] The following disclosure provides many different embodiments or examples for implementing various structures of this invention. To simplify the disclosure, specific examples of components and arrangements are described below. Of course, these are merely examples and are not intended to limit the scope of this invention.

[0047] The embodiments of the utility model will now be described in detail with reference to the accompanying drawings.

[0048] Example 1

[0049] See Figure 1 and Figure 2 An attenuation chip includes a ceramic substrate 1 and microstrip lines. For details on the specific attenuation chip structure and the distribution of the microstrip lines on the ceramic substrate 1, please refer to Chinese patent documents CN118659104A (publication date: September 17, 2024) and CN221486780U (publication date: August 6, 2024). In both of these patent documents, the front side of the ceramic substrate 1 is provided with microstrip lines for input or output signals. These microstrip lines are located in the middle of the left and right edge regions of the front side of the ceramic substrate 1. Whether for input or output signals, the microstrip lines form the connection portion of the attenuation chip, used to cooperate with the contact cap of a coaxial attenuator to achieve electrical connection.

[0050] In the prior art, the specific method of electrical connection between the attenuation chip and the contact cap can be found in Chinese patent document CN101950836A (publication date: January 19, 2011). In the coaxial attenuator disclosed in CN101950836A, the C-shaped elastic contact openings (referred to as grooves 3 in this application) of the contact pins (referred to as contact caps in this application) at the left and right ends of the attenuation chip are respectively engaged with the input microstrip line and the output microstrip line (referred to as the connection part of the attenuation chip in this application). The contact cap and the connection part of the attenuation chip are bonded or welded together with conductive adhesive. However, these two connection methods are prone to failure due to aging of conductive adhesive, cracking of solder joints, thermal cycling or vibration stress during long-term use, which affects the overall performance and lifespan of the device.

[0051] In this embodiment, a slot-shaped notch 2 is provided on the outside of the connection part of the attenuation chip, and the extension direction of the bottom wall of the notch 2 is perpendicular to the front side of the ceramic substrate 1; and it is inserted into the groove 3 of the contact cap, so that the contact cap is mechanically limited and fixed in both the radial and axial directions, thereby overcoming the reliability problem of using conductive glue or welding methods.

[0052] Specifically, the notch 2 is preferably rectangular or stepped opening structure. When the contact cap is inserted into the notch 2, the bottom wall of the groove 3 is adapted to abut against the bottom wall of the notch 2. The notch 2 forms steps 5 on the upper and lower sides of the bottom wall. The steps 5 fit on both sides of the base of the groove 3. When the attenuation chip is pressed against the contact cap, it can achieve stable mechanical clamping, prevent the contact cap from sliding along the side of the contact chip, limit the limit contact cap, and thus maintain reliable electrical and mechanical connection in long-term working environment.

[0053] To increase the stability of the limit and the vibration resistance, a positioning recess 6 is preferably provided on the bottom wall. The positioning recess 6 can be inserted and matched with the positioning protrusion 7 correspondingly provided on the bottom wall of the groove 3 of the contact cap, thereby further enhancing the mechanical fixing effect when the attenuation chip is inserted into the contact cap.

[0054] Due to current production technology and processing precision limitations, only one positioning recess 6 can be provided on the bottom wall of the notch 2 in the current production stage, and the bottom wall of the positioning recess 6 is arc-shaped. The positioning protrusion 7 of the contact cap has an arc-shaped protrusion structure that matches the arc-shaped bottom wall. However, with the improvement of production technology in the future, the positioning recess 6 may also be set as a V-groove structure. Therefore, the specific shape of the positioning recess 6 should not be limited. In addition, with the improvement of processing precision in the future, multiple positioning recesses 6 can be provided on the bottom wall of the notch 2. Therefore, the number of positioning recesses 6 should not be limited.

[0055] Example 2

[0056] Based on the above embodiment 1, in order to increase the reliability of the electrical connection between the contact cap and the attenuation chip.

[0057] A conductive metal layer 8 is provided on the bottom wall of notch 2, and the conductive metal layer 8 is electrically connected to the microstrip line. When the contact cap is inserted into the attenuation chip, the bottom wall of the groove 3 directly abuts against the conductive metal layer 8, forming a stable and reliable electrical path;

[0058] Specifically, the conductive metal layer 8 includes a metal thin film layer and an electroplated layer. The metal thin film layer is formed on the bottom wall of the notch 2 by a sputtering process, and the electroplated layer covers the metal thin film layer. The metal thin film layer is used to enhance the bonding force between the electroplated layer and the ceramic substrate 1 and to prevent the conductive layer from peeling off under thermal cycling or mechanical stress. The electroplated layer is formed by nickel-gold electroplating and is used to improve the overall conductivity and structural strength.

[0059] To further improve the bonding strength between the metal conductive layer 8 and the ceramic substrate 1, several pits are provided on the bottom wall of the notch 2. By increasing the contact area between the metal thin film layer and the ceramic substrate 1, the bonding force between the metal conductive layer 8 and the ceramic substrate 1 is enhanced.

[0060] Example 3

[0061] Based on the above embodiment 1, a specific attenuation chip setting scheme is provided.

[0062] The ceramic substrate 1 is rectangular, and the microstrip line includes an input microstrip line 11 and an output microstrip line 12.

[0063] The input microstrip line 11 and the output microstrip line 12 are spaced apart on both sides of the front side of the ceramic substrate 1, forming the input connection part and the output connection part of the attenuation chip, respectively.

[0064] The input and output connection parts of the attenuation chip are both provided with notches 2 on the outside, so as to be inserted and matched with the contact cap of the coaxial attenuator to achieve mechanical limiting and fixing and electrical connection;

[0065] The ceramic substrate 1 is preferably made of aluminum nitride material to provide excellent thermal conductivity and dielectric properties, thereby ensuring the stability of high-frequency signal transmission and the heat resistance and reliability of the attenuation chip during long-term use.

[0066] In addition, the front side of the ceramic substrate 1 is also provided with a grounding device and a resistor. The positional relationship and connection relationship between the grounding device, the resistor, the input microstrip line 11 and the output microstrip line 12 can be referred to the above-mentioned arrangement methods of CN118659104A and CN221486780U. This application only briefly describes them here: the microstrip lines arranged on the front side of the ceramic substrate 1 include the input microstrip line 11 and the output microstrip line 12. The input microstrip line 11 and the output microstrip line 12 are arranged at intervals in the middle of the left and right edges of the front side of the ceramic substrate 1.

[0067] The ceramic substrate 1 is also provided with a first grounding device and a second grounding device on the front side. The first grounding device and the second grounding device are arranged at intervals on the upper and lower sides of the front side of the ceramic substrate 1 and extend along the left and right direction of the ceramic substrate 1.

[0068] Example 4

[0069] See Figures 3 to 6 Based on the above embodiment 3, this embodiment provides a specific structure of a coaxial attenuator and an attenuation chip assembly scheme.

[0070] The coaxial attenuator includes a housing 13, an input pin 14, an output pin 15, an input contact cap 16, an output contact cap 17, and the attenuation chip in Embodiment 3; the housing 13 has an input connector 18 at its front end and an output connector 19 at its rear end; the input pin 14 and the output pin 15 are coaxially disposed in the input connector 18 and the output connector 19, respectively, to ensure coaxial transmission of radio frequency signals;

[0071] The first end of the input contact cap 16 is coaxially and elastically connected to the inner hole of the tail end of the input pin 14, and the tail end of the output contact cap 17 is coaxially and elastically connected to the inner hole of the first end of the output pin 15. The specific arrangement of the coaxial elastic connection is disclosed in Chinese patent document CN202839924U (publication date: July 24, 2012) and is a mature prior art, so it will not be described in detail here.

[0072] The input contact cap 16 and the output contact cap 17 are both provided with grooves 3, which are respectively inserted into the connection parts on the left and right sides of the attenuation chip, that is, the notches 2 of the input connection part and the output connection part, to achieve radial positioning of the attenuation chip; the input pin 14 and the output pin 15 clamp the two sides of the attenuation chip under the action of elasticity, thereby achieving axial positioning of the attenuation chip and ensuring the mechanical stability of the device in long-term use.

[0073] Specifically, the input pin 14 has a socket assembly 22 on its shaft, a pin 23 connected to the front end of the shaft, and an inner hole at the rear end of the shaft. The diameter of the shaft where it mates with the socket assembly 22 is 0.8 mm, the diameter of the rest is 1.27 mm, and the thickness of the attenuation chip is 1.04 mm. This design can effectively increase the operating frequency to 44 GHz.

[0074] The specific structure of the aforementioned socket assembly 22 includes an inner conductor, polystyrene casting material, etc., and the housing 13 is also equipped with grounding clamps and other devices, all of which are existing technologies and will not be described in detail here.

[0075] To enhance the mechanical limiting effect between the attenuation chip and the contact cap, a positioning recess 6 is provided on the bottom wall of the notch 2 of the input connection part, and a positioning protrusion 7 is provided on the bottom wall of the groove 3 of the input contact cap 16; and / or, a positioning recess 6 is provided on the bottom wall of the notch 2 of the output connection part, and a positioning protrusion 7 is provided on the bottom wall of the groove 3 of the output contact cap 17.

[0076] As mentioned above, due to the limitations of current production technology and processing precision, only one positioning recess 6 can be provided on the bottom wall of the notch 2 in the current production stage, and the bottom wall of the positioning recess 6 is arc-shaped, and the positioning protrusion 7 of the contact cap is an arc-shaped protrusion structure that matches the arc-shaped bottom wall.

[0077] The above specific embodiments further illustrate the purpose, technical solution and beneficial effects of this utility model. It should be understood that the above are only specific embodiments of this utility model and are not intended to limit the scope of protection of this utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model should be included within the scope of protection of this utility model.

Claims

1. An attenuation chip, characterized by: Includes ceramic substrate (1) and microstrip lines; Two microstrip lines are respectively disposed on the left and right edges of the front side of the ceramic substrate (1), forming the connection part of the attenuation chip for input or output signals; The outer side of the connection part of the attenuation chip is provided with a through groove-shaped notch (2), and the extension direction of the bottom wall of the notch (2) is perpendicular to the front side of the ceramic substrate (1); When the contact cap with the groove (3) is inserted into the notch (2), the bottom wall of the groove (3) abuts against the bottom wall of the notch (2), and the steps (5) on the upper and lower sides of the notch (2) cooperate with the two sides of the base of the groove (3) to limit the contact cap.

2. The attenuating chip of claim 1, wherein: The bottom wall of the notch (2) is provided with a positioning recess (6) for insertion and fixing with the positioning protrusion (7) corresponding to the bottom wall of the groove (3).

3. The attenuating chip of claim 1 or 2, wherein: A metal conductive layer (8) is provided on the bottom wall of the notch (2), and the metal conductive layer (8) is electrically connected to the microstrip line; When the contact cap is inserted into the attenuation chip, the metal conductive layer (8) abuts against the bottom wall of the groove (3).

4. The attenuating chip of claim 3, wherein: The conductive metal layer (8) includes a metal thin film layer and an electroplated layer. The metal thin film layer is sputtered on the bottom wall of the notch (2), and the electroplated layer covers the metal thin film layer.

5. The attenuating chip of claim 3, wherein: Several pits are provided on the bottom wall of the notch (2) to enhance the bonding strength between the metal conductive layer (8) and the ceramic substrate (1).

6. The attenuating die of claim 1, wherein: The ceramic substrate (1) is rectangular, and the microstrip lines on its front side include an input microstrip line (11) and an output microstrip line (12). The input microstrip line (11) and the output microstrip line (12) are spaced apart and disposed in the middle of the left and right edges of the front side of the ceramic substrate (1). The ceramic substrate (1) is also provided with a first grounding device and a second grounding device on the front side. The first grounding device and the second grounding device are arranged at intervals on the upper and lower sides of the front side of the ceramic substrate (1) and extend along the left and right direction of the ceramic substrate (1).

7. The attenuating die of claim 6, wherein: The ceramic substrate (1) is made of aluminum nitride material.

8. A coaxial attenuator, characterized by: It includes a housing (13), an input pin (14), an output pin (15), an input contact cap (16), an output contact cap (17), and an attenuation chip as described in any one of claims 1-6; The housing (13) has an input connector (18) at the front end and an output connector (19) at the rear end. The input pin (14) and the output pin (15) are coaxially arranged in the input connector (18) and the output connector (19), respectively. The first end of the input contact cap (16) is coaxially and elastically connected to the inner hole of the tail end of the input pin (14), and the tail end of the output contact cap (17) is coaxially and elastically connected to the inner hole of the first end of the output pin (15). The input contact cap (16) and the output contact cap (17) are both provided with grooves (3), which are inserted into the notches (2) on the left and right sides of the attenuation chip respectively, and are radially positioned for the attenuation chip. The input pin (14) and the output pin (15) clamp the two sides of the attenuation chip under the action of elastic force, and position the attenuation chip axially.

9. The coaxial attenuator of claim 8, wherein: The input pin (14) has a socket assembly (22) on its shaft, a needle (23) is connected to the first end of the shaft, and an inner hole is opened at the last end of the shaft; The diameter of the matching part of the shaft and the socket assembly (22) is 0.8mm, and the diameter of the rest part is 1.27mm; the thickness of the attenuation chip is 1.04mm.

10. The coaxial attenuator of claim 8, wherein: The bottom wall of the notch (2) of the input connecting part is provided with a positioning recess (6), and the bottom wall of the groove (3) of the input contact cap (16) is correspondingly provided with a positioning protrusion (7); And / or, the bottom wall of the notch (2) of the output connecting part is provided with a positioning recess (6), and the bottom wall of the groove (3) of the output contact cap (17) is correspondingly provided with a plurality of positioning protrusions (7).

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