Fuzz button type radio frequency coaxial fixed attenuator

Abstract

A fuzz button type radio frequency coaxial fixed attenuator belongs to the field of microwave radio frequency, and is characterized in that an attenuation slice assembly is arranged in a threaded connection area of a shell I and a shell II; the attenuation sheet assembly is composed of an attenuation sheet, a resistive film layer, a grounding conduction band, a grounding reed, a metallization layer and a lining. A first insulator is arranged on the inner side of the first shell, a second insulator is arranged on the inner side of the second shell, a jack and a contact pin are arranged on the inner side of the first insulator and the inner side of the second insulator respectively, blind holes are formed in the tail portions of the jack and the contact pin, fuzz buttons are arranged in the blind holes, and the hole diameter of the blind holes is larger than the enveloping outer diameter of the fuzz buttons. One end, close to the attenuation sheet, of the fuzz button abuts against the metallization layer; a screw sleeve is arranged outside one end of the shell II; a clamping ring and a sealing ring are arranged between the second shell and the threaded sleeve. According to the utility model, through elastic connection of the fuzz buttons, connection without plugging force between the inner conductors is realized, and the problem of failure caused by uneven stress in the plugging process is avoided.

Description

Technical Field

[0001] The utility model belongs to the field of microwave radio frequency, and in particular relates to a wool button type radio frequency coaxial fixed attenuator. Background Art

[0002] RF coaxial fixed attenuators are suitable for any occasion where power level needs to be reduced or circuit matching is required, and can quantitatively absorb energy in the transmission line.

[0003] The coaxial fixed attenuator is a type of microwave passive device. It uses a matching resistor network to dissipate part of the power and produce a certain amount of attenuation on the microwave signal so that the signal amplitude and power reach the required range. In addition, it can also be used for impedance matching, so that the impedance in the system is matched.

[0004] The Chinese invention patent application with patent number CN101950836A discloses a coaxial attenuator having a plug, a socket and an attenuation plate arranged therebetween. The invention has a simple structure, is easy to install, has good contact characteristics, can prevent torsional damage to the attenuation plate caused by the rotation of the inner conductor, and improves the RF performance. Analysis shows that the coaxial fixed attenuator with a traditional structure is to weld the pin to the attenuation plate, and then elastically plug and connect it to the tail of the inner conductor. This design often has problems such as poor welding reliability, low frequency of use, relatively high cost, and complex process. At the same time, improper plug-in and pull-out force will cause the risk of product failure. Utility Model Content

[0005] The utility model aims to provide a wool button type radio frequency coaxial fixed attenuator, which realizes a connection between inner conductors without plugging and unplugging force through the elastic connection of the wool button, thereby avoiding the problem of failure caused by uneven force during the plugging and unplugging process.

[0006] The technical solution adopted by the utility model is:

[0007] A button-type radio frequency coaxial fixed attenuator comprises a first shell and a second shell connected together by threads, and an attenuation sheet assembly is arranged inside the threaded connection area of ​​the first shell and the second shell; the attenuation sheet assembly is composed of an attenuation sheet, a resistance film layer, a grounding conductor, a grounding spring sheet, a metallized layer and a bushing;

[0008] An insulator 1 is provided on the inner side of the shell 1, an insulator 2 is provided on the inner side of the shell 2, a jack and a pin are provided on the inner side of the insulator 1 and the inner side of the insulator 2 respectively, a blind hole is provided at the tail of the jack and the pin, a wool button is provided in the blind hole, the aperture of the blind hole is larger than the outer diameter of the envelope of the wool button, and one end of the wool button close to the attenuation plate is pressed against the metallized layer;

[0009] A screw sleeve is arranged outside one end of the second shell; a clamping ring and a sealing ring are arranged between the second shell and the screw sleeve.

[0010] Furthermore, a resistive film layer is provided in the middle of the attenuation sheet by using a sputtering process, and at the same time, a grounding conductive strip is provided on the attenuation sheet by using an electroplating process; grounding spring sheets are clamped and provided at two end edges of the attenuation sheet, and a metallization layer is provided on the other two end sides; the attenuation sheet clamped with the grounding spring sheet is press-fitted into the bushing and elastically connected to the bushing groove to form a combination.

[0011] Furthermore, the attenuation plate adopts a coplanar waveguide structure, and the attenuator is designed according to a π-type circuit.

[0012] Furthermore, barb structures are designed between the insertion hole and the first insulator, and between the insertion pin and the second insulator, so as to achieve stable connection in the axial and radial directions.

[0013] Furthermore, the wool button is made of gold-plated beryllium bronze wire that is randomly wound, and is naturally formed by molding the edges and corners. The compression amount of the wool button is 15% to 20% of the total length.

[0014] Beneficial effects of the utility model:

[0015] The utility model realizes a connection between the inner conductors without plugging and unplugging force through the elastic connection of the wool button, avoiding the problem of failure caused by uneven force during plugging and unplugging; at the same time, it realizes a non-welding connection between the inner conductor and the attenuation plate, avoiding the problem of cracking and failure of the attenuation plate caused by the different expansion coefficients of the ceramic substrate (attenuation plate substrate) and the welded inner conductor during welding and use. In addition, the transmission frequency of the wool button is as high as 40GHz, which is higher than the traditional welding structure. The elastic connection between the attenuation plate and the bushing through the grounding spring can reduce the risk of cracking of the attenuation plate during vibration and impact. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a schematic diagram of the overall structure of the utility model;

[0017] Figure 2 It is a front view of the attenuator and a view of the metallized layers on the sides of the attenuator. The code 301 in the figure refers to the attenuator substrate that is not covered with the grounding conductor.

[0018] Figure 3 It is a diagram of the composition and assembly process of the attenuation sheet assembly;

[0019] Figure 4 It is a schematic diagram of the grounding spring;

[0020] Figure 5 It is a diagram of the assembly process of the attenuation sheet assembly and the fur buttons and other components;

[0021] In the figure, 1, shell 1, 2, shell 2, 3, attenuation plate assembly, 301, attenuation plate, 302, resistor film layer, 303, grounding conductor, 304, grounding spring, 305, metallized layer, 306, bushing, 4, insulator 1, 5, insulator 2, 6, jack, 7, pin, 8, wool button, 9, screw sleeve, 10, retaining ring, 11, sealing ring. DETAILED DESCRIPTION

[0022] Figure 1-Figure 5 In the embodiment, a button-type radio frequency coaxial fixed attenuator comprises a housing 1 and a housing 2 which are threadedly connected together, and an attenuation sheet assembly 3 is arranged inside the threaded connection area of ​​the housing 1 and the housing 2; the attenuation sheet assembly 3 is composed of an attenuation sheet 301, a resistance film layer 302, a grounding conductor 303, a grounding spring sheet 304, a metallized layer 305 and a bushing 306;

[0023] An insulator 1 4 is provided inside the shell 1, an insulator 2 5 is provided inside the shell 2, a jack 6 and a pin 7 are provided inside the insulator 1 4 and the insulator 2 5 respectively, a blind hole is provided at the tail of the jack 6 and the pin 7, a wool button 8 is provided in the blind hole, the aperture of the blind hole is larger than the outer diameter of the envelope of the wool button 8, and one end of the wool button 8 close to the attenuation plate 301 presses against the metallized layer 305;

[0024] A threaded sleeve 9 is arranged outside one end of the second shell 2 ; a clamping ring 10 and a sealing ring 11 are arranged between the second shell 2 and the threaded sleeve 9 .

[0025] A resistance film layer 302 is provided in the middle of the attenuation sheet 301 by using a sputtering process, and at the same time, a grounding conductive strip 303 is provided on the attenuation sheet 301 by using an electroplating process; grounding spring sheets 304 are clamped at two end edges of the attenuation sheet 301, and a metallization layer 305 is provided on the other two end sides; the attenuation sheet 301 clamped with the grounding spring sheet 304 is press-fitted into the bushing 306, and elastically connected to the groove of the bushing 306 to form a combination.

[0026] The attenuation plate 301 adopts a coplanar waveguide structure, and the attenuator is designed according to a π-type circuit.

[0027] Barb structures are designed between the insertion hole 6 and the insulator 1 4, and between the insertion pin 7 and the insulator 2 5, so as to achieve stable connection in the axial and radial directions.

[0028] The wool button 8 is made of gold-plated beryllium bronze wire randomly wound, and is naturally formed by molding each corner. The compression amount of the wool button 8 is 15% to 20% of the total length.

[0029] The attenuation plate 301 adopts an alumina ceramic substrate, the resistor film layer adopts a tantalum nitride sputtering process, and the conductive strip and the side metallization layer are nickel-based gold-plated.

[0030] After the wool button 8 is compressed, its envelope outer diameter becomes larger and stably contacts with the inner wall of the tail blind hole of the pin 7 and the socket 6. The compression connection of the wool button 8 turns on the inner conductor, realizing continuous and stable transmission of the signal.

[0031] The grounding spring 304 is an elastic contact piece, made of beryllium bronze plated with gold, and the bushing 306 is made of brass plated with gold. The grounding spring 304 clamps the two ends of the attenuation plate 301 respectively, and then is pressed into the bushing 306 together, and is elastically connected to the groove of the bushing 306 to form the attenuation plate assembly 3.

[0032] The metallized layers 305 at both ends of the attenuation plate 301 are elastically connected to the inner conductor through the wool buttons 8, and the grounding conductors 303 at both sides of the attenuation plate 301 are elastically connected to the bushing 306 through the grounding springs 304. The two ends of the attenuator 301 are designed according to the SMA standard interface. According to the formula Determine the size of the inner and outer conductors, where: impedance Z0 = 50Ω, ε r is the dielectric constant of the insulator. During the design, HFSS electrical simulation is used to determine the size of the bushing air cavity, and the impedance matching of the attenuation sheet is achieved by adjusting the size of the bushing air cavity.

[0033] During assembly, the jack 6 and the insulator 1 4 are installed into the housing 1, the pin 7 and the insulator 2 5 are installed into the housing 2 2, and after the housing 1 1 and the housing 2 2 are assembled, the attenuation plate assembly 3 is installed into the threaded connection part of the housing 1 1 and the housing 2 2, and finally the sealing ring 11, the retaining ring 10 and the screw sleeve 9 are installed.

Claims

1. A button-type RF coaxial fixed attenuator, characterized in that: The invention comprises a first shell (1) and a second shell (2) which are threadedly connected together, and an attenuation sheet assembly (3) is arranged inside the threaded connection area of ​​the first shell (1) and the second shell (2); the attenuation sheet assembly (3) is composed of an attenuation sheet (301), a resistance film layer (302), a grounding conductor (303), a grounding spring sheet (304), a metallized layer (305) and a bushing (306); An insulator 1 (4) is provided on the inner side of the shell 1 (1), an insulator 2 (5) is provided on the inner side of the shell 2 (2), a plug hole (6) and a plug pin (7) are provided on the inner side of the insulator 1 (4) and the inner side of the insulator 2 (5), respectively, a blind hole is provided at the tail of the plug hole (6) and the plug pin (7), a wool button (8) is provided in the blind hole, the aperture of the blind hole is larger than the outer diameter of the envelope of the wool button (8), and one end of the wool button (8) close to the attenuation plate (301) presses against the metallized layer (305); A screw sleeve (9) is arranged outside one end of the second shell (2); a clamping ring (10) and a sealing ring (11) are arranged between the second shell (2) and the screw sleeve (9).

2. A button-type RF coaxial fixed attenuator as claimed in claim 1, characterized in that: A resistive film layer (302) is disposed in the middle of the attenuation sheet (301) by using a sputtering process, and at the same time, a grounding conductive strip (303) is disposed on the attenuation sheet (301) by using an electroplating process; grounding spring sheets (304) are clamped and disposed at two ends of the attenuation sheet (301), and a metallization layer (305) is disposed on the other two ends; the attenuation sheet (301) clamped with the grounding spring sheet (304) is press-fitted into a bushing (306), and elastically connected to a groove of the bushing (306) to form a combined body.

3. The button-type RF coaxial fixed attenuator according to claim 1, characterized in that: The attenuation plate (301) adopts a coplanar waveguide structure and is designed as an attenuator according to a π-type circuit.

4. The button-type RF coaxial fixed attenuator according to claim 1, characterized in that: Barb structures are designed between the insertion hole (6) and the first insulator (4), and between the insertion pin (7) and the second insulator (5), so as to achieve stable connection in the axial and radial directions.

5. The button-type RF coaxial fixed attenuator as claimed in claim 1, characterized in that: The wool button (8) is made of gold-plated beryllium bronze wire that is randomly wound and naturally formed through molding of the edges and corners. The compression amount of the wool button (8) is 15% to 20% of the total length.

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