New SMA type RF coaxial connector

Abstract

The present invention relates to a novel SMA type radio frequency coaxial connector, comprising a first housing, a connecting screw sleeve rotatably sleeved on the first housing, an inner conductor disposed within the first housing, an insulating assembly for fixing the inner conductor within the first housing, a bushing disposed within the first housing and located behind the inner conductor, and a second housing connected to the rear end of the first housing and for pressing the bushing within the first housing. The bushing comprises a first bushing section and a second bushing section formed by the rear end of the first bushing section extending rearward along the axial direction of the connector. The inner diameter of the first bushing section is smaller than the inner diameter of the second bushing section. Welding holes are respectively provided on the first bushing section and the second bushing section. When the connector is welded and assembled with a cable, the inner shielding layer and the outer shielding layer of the cable are welded and fixed to the first bushing section and the second bushing section, respectively, which greatly increases the stability of the inner shielding layer of the cable, can obtain better electrical performance indicators, improve the high-frequency performance of the connector, and ensure the reliability of the connection.

Description

Technical Field

[0001] The present invention belongs to the technical field of radio frequency coaxial connectors, and in particular relates to a novel SMA type radio frequency coaxial connector. Background Art

[0002] Conventional RF coaxial connectors are divided into microstrip RF coaxial connectors and coaxial cable RF connectors according to their use. The structures of coaxial cable RF connectors can be divided into: welding structure, crimping structure, and assembly structure.

[0003] For example, Chinese patent CN206742606U discloses an SMA radio frequency coaxial connector, which includes a shell, a first insulator and a second insulator installed in the shell, a pin installed in the first insulator, a slot at the tail of the pin, an air medium between the first insulator and the second insulator, a bushing inside the shell and at the rear end of the second insulator, the inner conductor of the cable is fixed by welding the insulator and the pin, the cable shielding layer is fixed by welding the bushing, and the outer sheath of the cable is threadedly connected to the shell by screws.

[0004] To achieve excellent shielding, current RF coaxial cables typically utilize a double-shield structure, with a non-metallic layer between the two shields for superior mechanical stability. In current RF coaxial connectors, the bushing is typically welded to the cable's outer shield. However, the inner shield often plays a primary role in RF signal transmission, and its lack of stability results in poor high-frequency performance. This prevents current welded connectors from achieving optimal electrical performance and connection reliability. Summary of the Invention

[0005] In order to solve the deficiencies in the prior art, the present invention provides an improved SMA type radio frequency coaxial connector.

[0006] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0007] An SMA type radio frequency coaxial connector includes a first shell, a connecting screw sleeve rotatably mounted on the first shell, an inner conductor arranged in the first shell, an insulating component arranged in the first shell for fixing the inner conductor in the first shell, a bushing arranged in the first shell and located behind the inner conductor, and a second shell connected to the rear end of the first shell and used for pressing the bushing into the first shell, the bushing includes a bushing section extending along the axial direction of the connector and a bushing section formed by the rear end of the bushing section extending backward along the axial direction of the connector, the inner diameter of the bushing section is smaller than the inner diameter of the bushing section, the bushing section has a plurality of first welding through holes distributed in sequence along its circumferential direction, and the bushing section has a plurality of second welding through holes distributed in sequence along its circumferential direction.

[0008] In a further embodiment, the second shell is sleeved on the bushing and the front end outer side surface of the bushing section protrudes outward along its radial direction to form an extension portion, and the extension portion is clamped between the front end portion of the second shell and the first shell.

[0009] In a further embodiment, a first blocking portion for confining the bushing between the front end portion of the second shell and the first shell is formed on the inner side wall of the rear end portion of the first shell.

[0010] In a further embodiment, the rear end of the bushing is located within the second housing.

[0011] In a further embodiment, the bushing further includes a bushing section 3 formed by the rear end portion of the bushing section 2 extending rearwardly along the axial direction of the connector.

[0012] In a further embodiment, an internal thread is provided on an inner side wall of the rear end of the first shell, and an outer side surface of the front end of the second shell has an external thread that can be threadably connected to the internal thread of the first shell.

[0013] In a further embodiment, the insulating assembly includes an insulator sleeved on the inner conductor and located between the first outer shell and the inner conductor, and an insulating sheet arranged behind the inner conductor and located between the inner conductor and the bushing, and the bushing also presses the insulating sheet between the first outer shell and the front end of the bushing.

[0014] In a further embodiment, a second blocking portion for confining the insulating sheet between the first housing and the front end portion of the bushing is formed on the inner side wall of the rear end portion of the first housing.

[0015] Preferably, a step is formed on the outer side of the front end of the insulator along the axial direction of the insulator, and a first boss is formed on the inner wall of the front end of the first shell along the radial direction of the first shell, which can cooperate and abut against the step. The step and the first boss cooperate and abut to prevent the insulator from sliding toward the front end of the connector and detaching from the first shell.

[0016] More preferably, the inner conductor includes an inner conductor segment one located at the front end of the connector and extending along the axial direction of the connector, an inner conductor segment two formed by the rear end portion of the inner conductor segment one extending rearward along the axial direction of the connector, and an inner conductor segment three formed by the rear end portion of the inner conductor segment two extending rearward along the axial direction of the connector, the outer diameter of the inner conductor segment one is smaller than the outer diameter of the inner conductor segment two, the outer diameter of the inner conductor segment two is smaller than the outer diameter of the inner conductor segment three, and the insulator is sleeved on the inner conductor segment two and abuts against the inner conductor segment three.

[0017] Due to the application of the above technical solution, the present invention has the following advantages compared with the prior art:

[0018] The connector of the present invention is configured to have a bushing section one and a bushing section two with different inner diameters, and respectively provide welding through holes in the bushing section one and the bushing section two. When the cable is welded and assembled, the inner shielding layer and the outer shielding layer of the cable are respectively welded and fixed to the bushing section one and the bushing section two, thereby greatly increasing the stability of the inner shielding layer of the cable, achieving better electrical performance indicators, better high-frequency performance of the connector, and ensuring the reliability of the connection. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 A schematic diagram of a half-section structure of an SMA type radio frequency coaxial connector according to a specific embodiment of the present invention;

[0020] Figure 2 A schematic cross-sectional view of an insulator of an SMA type radio frequency coaxial connector according to a specific embodiment of the present invention;

[0021] Figure 3 A schematic diagram of a half-section structure of an SMA type radio frequency coaxial connector after being assembled with a cable according to a specific embodiment of the present invention;

[0022] In the figure: 1. inner conductor; 1a. one section of inner conductor; 1b. two sections of inner conductor; 1c. three sections of inner conductor; 2. first outer shell; 2a. first boss; 2b. first blocking portion; 2c. second blocking portion; 3. insulating sheet; 4. insulator; 4a. step; 4b. second boss; 4c. raised portion; 5. bushing; 5a. one section of bushing; 5b. two sections of bushing; 5c. three sections of bushing; 5d. first welding through-hole; 5e. second welding through-hole; 6. connecting screw; 7. second outer shell; 8. retaining ring; 9. sealing ring; 10. cable; 10a. cable core; 10b. inner shielding layer; 10c. outer shielding layer. DETAILED DESCRIPTION

[0023] The present invention will be further described below with reference to the accompanying drawings:

[0024] like Figures 1-3 The SMA type RF coaxial connector shown includes a first shell 2, a connecting screw sleeve 6 rotatably sleeved on the first shell 2, an inner conductor 1 arranged in the first shell 2, an insulating component arranged in the first shell 2 for fixing the inner conductor 1 in the first shell 2, a bushing 5 arranged in the first shell 2 and located behind the inner conductor 1, and a second shell 7 sleeved on the bushing 5 and connected to the rear end of the first shell 2. The second shell 7 is also used to press and fix the bushing 5 in the first shell 2.

[0025] See also Figure 1As shown, the bushing 5 includes a first bushing section 5a extending along the axial direction of the connector, a second bushing section 5b extending rearwardly from the rear end of the first bushing section 5a along the axial direction of the connector, and a third bushing section 5c extending rearwardly from the rear end of the second bushing section 5b along the axial direction of the connector. The inner diameter of the first bushing section 5a is smaller than that of the second bushing section 5b, which in turn is smaller than that of the third bushing section 5c. The first bushing section 5a has a plurality of first welding holes 5d distributed along its circumference, while the second bushing section 5b has a plurality of second welding holes 5e distributed along its circumference. Specifically, the number of the first welding holes 5d and the number of the second welding holes 5e can be 2, 3, 4, or more, respectively, depending on the cable to be welded. When assembled with an external cable, the inner shielding layer of the cable is welded to the first section 5a of the sleeve through the first welding hole 5d, the outer shielding layer of the cable is welded to the second section 5b of the sleeve through the second welding hole 5e, and the third section 5c of the sleeve is sleeved on the outer sheath of the cable.

[0026] The front outer side surface of bushing section 1a protrudes outward in its radial direction to form an extension, which is located between the front end of second housing 7 and first housing 2. First welding hole 5d is located behind the extension. The rear end of bushing section 3c is located within second housing 7.

[0027] In this example, the insulating assembly includes an insulator 4 that is sleeved on the inner conductor 1 and located between the first outer shell 2 and the inner conductor 1, and an insulating sheet 3 that is arranged behind the inner conductor 1 and located between the inner conductor 1 and the bushing 5. The bushing 5 also presses and fixes the insulating sheet 3 between the first outer shell 1 and the front end of the bushing 5.

[0028] Specifically, a first blocking portion 2b for limiting the bushing 5 between the front end portion of the second shell 7 and the first shell 2 and a second blocking portion 2c for limiting the insulating sheet 3 between the front end portion of the bushing 5 and the first shell 2 are arranged in sequence along the axial direction on the rear end inner wall of the first shell 2, and the first blocking portion 2b is located behind the second blocking portion 2c.

[0029] See also Figure 2 As shown, the outer side of the front end of the insulator 4 in this example is concave inward along the axial direction of the insulator 4 to form a step 4a, and the inner wall of the front end of the first shell 2 is convex inward along the radial direction of the first shell 2 to form a first boss 2a that can cooperate with and abut the step 4a. The step 4a abuts the first boss 2a to prevent the insulator 4 from sliding toward the front end of the connector and separating from the first shell 2.

[0030] The height H of the step 4a along the axial direction of the insulator 4 is 0.2±0.05 mm.

[0031] A step is also formed on the outer side of the front end of the insulating sheet 3 along the axial direction of the insulating sheet 3 , and the step of the insulating sheet 3 cooperates and abuts against the second blocking portion 2 c.

[0032] In this example, the inner conductor 1 includes an inner conductor segment 1a located at the front end of the connector and extending in the axial direction of the connector, an inner conductor segment 1b formed by the rear end of the inner conductor segment 1a extending rearward in the axial direction of the connector, and an inner conductor segment 1c formed by the rear end of the inner conductor segment 1b extending rearward in the axial direction of the connector. The outer diameter of the inner conductor segment 1a is smaller than the outer diameter of the inner conductor segment 1b, and the outer diameter of the inner conductor segment 1b is smaller than the outer diameter of the inner conductor segment 1c. The insulator 4 is sleeved on the inner conductor segment 1b and abuts against the front end surface of the inner conductor segment 1c.

[0033] A second boss 4b extends axially outward from the inner side of the rear end of insulator 4. This boss 4b abuts the front end of the third inner conductor segment 1c, pressing the insulator 4 between the first housing 2 and the inner conductor 1. The rear end of the third inner conductor segment 1c has an axially defined jack for inserting an external cable. The front end of the first inner conductor segment 1a is tapered and serves as a contact pin.

[0034] A protrusion 4 c is formed on the side surface of the rear end of the insulator 4 and protrudes outward in the radial direction of the insulator 4 for pressing the insulator 4 tightly between the inner conductor 1 and the first housing 2 .

[0035] Specifically, the front end face of the insulating sheet 3 abuts against the rear end face of the inner conductor 1, and the insulator 4 is sleeved on the inner conductor second section 1b of the inner conductor 1, so that a cavity is formed between the inner conductor third section 1c and the first shell 2, and the cavity is filled with air, so that an air transition is adopted between the insulator 4 and the insulating sheet 3.

[0036] An internal thread is provided on the inner wall of the rear end of the first shell 2, and the internal thread is located behind the first blocking portion 2b. An external thread is provided on the outer side of the front end of the second shell 7, which can be threadedly connected with the internal thread of the first shell 2.

[0037] In this example, a first groove is provided on the outer side surface of the front end of the first shell 2 along its circumference, and a second groove corresponding to the first groove is provided on the inner wall of the connecting screw sleeve 6. A snap ring 8 is provided in the first groove and the second groove. The first shell 2 and the connecting screw sleeve 6 are movably connected through the snap ring 8. The snap ring 8 can not only clamp the connecting screw sleeve 6 on the front end of the first shell 2, but also ensure that the connecting screw sleeve 6 can rotate relative to the first shell 2.

[0038] An inserting groove is provided between the front end of the first housing 2 and the connecting screw sleeve 6 , and a sealing ring 9 sleeved on the outside of the first housing 2 is provided in the inserting groove.

[0039] In this example, the connecting screw sleeve 6, the first housing 2 and the second housing 7 are all made of stainless steel, which improves the environmental resistance and reliability of the connector. The connecting screw sleeve 6 is provided with a lead sealing hole, which is fixed by a lead wire to improve the connection reliability.

[0040] See also Figure 3 As shown, the assembly process of the SMA type RF coaxial connector and the external cable 10 in this example is as follows: the cable 10 passes through the second shell 7, and then the first section 5a of the bushing is welded to the inner shielding layer 10b of the cable 10 through the first welding through-hole 5d, and the second section 5b of the bushing is welded to the outer shielding layer 10c of the cable 10 through the second welding through-hole 5e, the insulating sheet 3 is sleeved on the cable core wire 10a, and then the cable core wire 10a is inserted into the jack at the rear end of the inner conductor 1 and the inner conductor 1 and the cable core wire 10a are welded, and then they are installed together into the first shell 2 which has the insulator 4 installed, and the inner conductor 1 is inserted into the insulator 4, and then the second shell 7 is threadedly connected to the first shell 2, and then the bushing 5 and the insulating sheet 3 are pressed between the first shell 2 and the second shell 7, so that the insulator 4 and the inner conductor 1 are fixed in the first shell 2. Then install the snap ring 8 in the first groove, install the sealing ring 9 at the corresponding position of the front end of the first shell 2, and finally put the connecting screw sleeve 6 on the front end of the first shell 2 so that the outer periphery of the snap ring 8 is stuck in the second groove, and the assembly is completed.

[0041] Through the above settings, the SMA type RF coaxial connector has the following advantages:

[0042] 1) The connector is configured with a bushing having a first bushing section and a second bushing section with different inner diameters, and welding through holes are respectively provided in the first bushing section and the second bushing section. When the cable is welded and assembled, the inner shielding layer and the outer shielding layer of the cable are welded and fixed to the first bushing section and the second bushing section respectively, which greatly increases the stability of the inner shielding layer of the cable, can obtain better electrical performance indicators, and can also improve the high-frequency performance of the connector and ensure the reliability of the connection.

[0043] 2) The second shell of the connector is mounted on the bushing and the rear end of the bushing is located within the second shell. The welding part of the bushing is contained within the second shell, so that when the cable assembly is used later and the tail of the connector is bent, the welding part will not be directly subjected to external force, thereby enhancing its reliability.

[0044] 3) By providing a step on the front end face of the insulator and cooperating with the design of the first boss on the front end face of the first shell, the insulator can be fixed between the inner conductor and the first shell after the connector is assembled. The assembly is both reliable and convenient, and the connector interface dimensions can be fully guaranteed. In addition, the insulator of the connector will not fall off during temperature testing or changes in the ambient temperature after assembly, which can fully ensure reliable signal transmission. The assembly operation of the connector is simple, which improves the yield rate and work efficiency.

[0045] 4) The insulator and the inner conductor of the connector are connected by a second boss that abuts against the front end surfaces of the three sections of the inner conductor. An insulating sheet is provided at the rear end of the inner conductor to press the inner conductor between the insulator and the insulating sheet, so that the inner conductor will neither shrink nor be displaced due to the movement of the inner conductor of the cable, ensuring the reliable transmission of signals when the assembled cable assembly is in use.

[0046] 5) The connector adopts a step misalignment compensation design between the inner conductor and the first shell, and an air transition is used in the rear section, which ensures the superior high-frequency electrical performance of the entire connector and makes the high-frequency electrical performance indicators very ideal.

[0047] 6) The front end of the connector's insulating sheet adopts a step design, which further ensures the superior high-frequency performance of the entire connector and makes the high-frequency electrical performance indicators ideal.

[0048] In short, when the connector is assembled with the cable, the connector is reliably welded to the cable with double shielding layers, which greatly increases the stability of the inner shielding layer of the cable, can obtain better electrical performance indicators, the high-frequency performance of the connector is better, and can also ensure the reliability of the connection, improve the yield of the connector assembly, and improve work efficiency.

[0049] The above embodiments are intended only to illustrate the technical concepts and features of the present invention. Their purpose is to enable those skilled in the art to understand the contents of the present invention and implement them accordingly. They are not intended to limit the scope of protection of the present invention. Any equivalent changes or modifications made in accordance with the spirit of the present invention are intended to be covered by the scope of protection of the present invention.

Claims

1. An SMA-type radio frequency coaxial connector, comprising a first housing, a connecting screw sleeve rotatably mounted on the first housing, an inner conductor disposed within the first housing, an insulating assembly disposed within the first housing for securing the inner conductor within the first housing, a bushing disposed within the first housing and located behind the inner conductor, and a second housing connected to the rear end of the first housing and for pressing the bushing into the first housing, characterized in that: The bushing includes a bushing section extending along the axial direction of the connector and a bushing section two formed by the rear end portion of the bushing section extending rearwardly along the axial direction of the connector. The inner diameter of the bushing section one is smaller than the inner diameter of the bushing section two. The bushing section one has a plurality of first welding through holes distributed sequentially along its circumferential direction, and the bushing section two has a plurality of second welding through holes distributed sequentially along its circumferential direction. The bushing also includes a bushing section three formed by the rear end portion of the bushing section two extending rearwardly along the axial direction of the connector. The inner diameter of the bushing section two is smaller than the inner diameter of the bushing section three. The insulating assembly includes an insulator sleeved on the inner conductor and located between the first shell and the inner conductor, and an insulating sheet arranged behind the inner conductor and located between the inner conductor and the bushing, wherein the bushing further presses the insulating sheet between the first shell and the front end of the bushing; The inner conductor includes an inner conductor section located at the front end of the connector and extending along the axial direction of the connector, an inner conductor section 2 formed by the rear end of the inner conductor section 1 extending rearward along the axial direction of the connector, and an inner conductor section 3 formed by the rear end of the inner conductor section 2 extending rearward along the axial direction of the connector. The outer diameter of the inner conductor section 1 is smaller than the outer diameter of the inner conductor section 2, and the outer diameter of the inner conductor section 2 is smaller than the outer diameter of the inner conductor section 3. The insulator is sleeved on the inner conductor section 2 and abuts against the inner conductor section 3.

2. The SMA type radio frequency coaxial connector according to claim 1, wherein: The second outer shell is sleeved on the bushing, and the front end outer side surface of the bushing section protrudes outward along its radial direction to form an extension portion, which is clamped between the front end portion of the second outer shell and the first outer shell.

3. The SMA type radio frequency coaxial connector according to claim 2, wherein: A first blocking portion for limiting the bushing between the front end portion of the second shell and the first shell is formed on the inner side wall of the rear end portion of the first shell.

4. The SMA type radio frequency coaxial connector according to claim 2, wherein: The rear end of the bushing is located within the second housing.

5. The SMA type radio frequency coaxial connector according to claim 1, wherein: An internal thread is provided on the inner side wall of the rear end of the first shell, and an external thread is provided on the outer side surface of the front end of the second shell that can be threadedly connected to the internal thread of the first shell.

6. The SMA type radio frequency coaxial connector according to claim 1, wherein: A second blocking portion for limiting the insulating sheet between the first housing and the front end portion of the bushing is formed on the rear end inner side wall of the first housing.

7. The SMA type radio frequency coaxial connector according to claim 1, wherein: The outer side of the front end of the insulator is concave inwardly along the axial direction of the insulator to form a step, and the inner wall of the front end of the first shell is convex inwardly along the radial direction of the first shell to form a first boss that can cooperate and abut against the step. The step and the first boss cooperate and abut to prevent the insulator from sliding toward the front end of the connector and separating from the first shell.

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