High isolation dual-section circulator / isolator and method of assembly

Abstract

This invention discloses a high-isolation dual-section circulator / isolator and its assembly method, belonging to the field of circulators and isolators. Its structure includes a cavity containing a central conductor, and a circuit board at the bottom. The central conductor includes three first pins and one second pin. Two positioning bosses are located at the bottom of the cavity, and two alignment holes are provided on the circuit board, with the two positioning bosses located in the two alignment holes respectively. A pin hole is provided on each of the first pins. Corresponding to the three pin holes, a bottom hole is provided on the circuit board. Three central pins sequentially pass through the three pin holes and the bottom hole directly below them, and are welded to the pin holes and the bottom hole. The second pin is bent upwards and welded to the load for conductivity. This invention reduces processing steps, improves production efficiency, and avoids the risk of open circuits caused by improper bending of the central conductor pins. Furthermore, the pin holes can be used to position the central conductor during assembly, ensuring device consistency and facilitating mass production.

Description

Technical Field

[0001] This invention relates to a circulator / isolator and its assembly method, and more particularly to a high-isolation dual-section circulator / isolator and its assembly method. Background Technology

[0002] With the rapid development of the communications field, circulators / isolators are widely used in communications, mainly in the base station radio frequency circuits of communication systems, serving as both unidirectional transmission and full-duplex transceiver. As the requirements for isolator isolation become increasingly stringent, integrated dual-cavity circulator-isolator assemblies are typically used in designs to meet these needs.

[0003] A common dual-section circulator isolator has a drop-in structure, consisting of a cavity with two inner chambers. In each inner chamber, stacked from bottom to top, are a ferrite substrate, a center conductor, another ferrite substrate, a ground plane, a permanent magnet, a temperature compensation plate, and a cover plate. A circuit board is soldered to the bottom of the cavity. The center conductor has four pins; three are bent downwards and soldered to the circuit board for conductivity, while the other is soldered to the load.

[0004] The assembly methods can be broadly divided into the following two types:

[0005] One method involves stacking the internal components without bending the four pins of the center conductor initially. The portion of the center conductor extending outside the cavity is used to position the center conductor relative to the cavity, achieving better component consistency. After assembly, the center conductor pins are bent and soldered to the bottom circuit board and load. This assembly method, which bends the center conductor after internal assembly to ensure component consistency, significantly increases the difficulty of the bending process and is not conducive to mass production.

[0006] Another method involves first bending the center conductor into shape, and then stacking and assembling the internal components. However, in this assembly method, the center conductor extends too little out of the cavity, making it difficult to position and potentially leading to inconsistent device performance. Summary of the Invention

[0007] The purpose of this invention is to provide a high-isolation dual-section circulator / isolator and its assembly method that solves the above problems, is simple to process and assemble, has good component consistency, and is beneficial for mass production.

[0008] To achieve the above objectives, the technical solution adopted by the present invention is as follows: a high isolation dual-section circulator / isolator includes an open cavity at the top, the cavity including two parallel and connected inner cavities, a central conductor in the inner cavity, a circuit board at the bottom of the cavity, the central conductor including three first pins connected to the circuit board and one second pin connected to the load, the side wall of the cavity having three notches for the first pins to be inserted from top to bottom and a through hole for the second pin to pass through from the inside to the outside, the bottom of the cavity having two positioning bosses, and the circuit board having two alignment holes that match the positioning bosses, the two positioning bosses being located in the two alignment holes respectively;

[0009] Each of the three first pins of the central conductor has a pin hole. Corresponding to the three pin holes, the circuit board has a bottom hole. The three central pins pass through the three pin holes and the bottom hole directly below them in sequence, and are soldered to the pin holes and the bottom hole.

[0010] The second pin is bent upwards to form a load lead and soldered to the load for conductivity.

[0011] Preferably, the two positioning bosses are located directly below the two inner cavities in the cavity.

[0012] An assembly method for a high-isolation dual-section circulator / isolator includes the following steps;

[0013] (1) Processing the center conductor;

[0014] Needle holes are provided at the three first pins of the center conductor, and the second pins are bent to form load leads;

[0015] (2) Assemble the cavity;

[0016] Inside the two cavities, from bottom to top, a ferrite substrate, a center conductor, an upper ferrite substrate, a ground plane, a permanent magnet, a temperature compensation plate, and a cover plate are stacked sequentially. The three first pins of the center conductor are located at three notches, and the second pins extend from the vias.

[0017] (3) Select a positioning fixture. The upper surface of the positioning fixture is provided with a positioning groove. The inner wall shape of the positioning groove matches and fits the outer wall shape of the circuit board. The positioning groove is provided with two countersunk holes for accommodating the positioning boss. The positioning groove is also provided with at least 4 positioning pins. The position of each positioning pin corresponds to a needle hole. When the positioning boss is located in the countersunk hole, the positioning pin passes through the needle hole to position the center conductor.

[0018] (4) The soldering surface of the circuit board is tinned. The whole obtained in step (3) is removed from the positioning fixture and its lower surface is in contact with the upper surface of the circuit board. The positioning boss passes through the alignment hole and is located in the countersunk hole. At this time, the three pin holes at the three first pins are exactly aligned with the three bottom holes of the circuit board.

[0019] (5) The three center pins pass through the three pin holes and the bottom hole of the circuit board below them respectively, and solder is applied at the position where the center pins pass through the pin holes and the bottom hole of the circuit board;

[0020] (6) The load is attached to the outer wall of the cavity and in contact with the load lead. The contact points between the load and the cavity and the load lead are tinned.

[0021] (7) Place the whole obtained in step (6) on a heating platform or reflow soldering, and wait for the solder to melt to complete the soldering.

[0022] Compared with the prior art, the advantages of the present invention are as follows:

[0023] The center conductor is connected to the circuit board via a center pin. This structure reduces the bending process of the center conductor during production, thus improving production efficiency. At the same time, it avoids the risk of open circuit caused by improper bending of the center conductor pin.

[0024] Because the center conductor has a pinhole, and it can be well positioned during assembly, the consistency of the device can be well guaranteed. This is beneficial for mass production of the device. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the structure of the present invention;

[0026] Figure 2 for Figure 1 A schematic diagram of the decomposed structure;

[0027] Figure 3 This is a schematic diagram of the central conductor;

[0028] Figure 4 This is a schematic diagram of a circuit board;

[0029] Figure 5 This is a structural schematic diagram of the cavity from another angle;

[0030] Figure 6 This is a structural diagram of the positioning fixture used during assembly.

[0031] In the diagram: 1. Cavity; 2. Cover plate; 3. Center conductor; 4. Circuit board; 5. First pin; 6. Second pin; 7. Notch; 8. Through hole; 9. Positioning boss; 10. Alignment hole; 11. Pin hole; 12. Bottom hole of circuit board; 13. Center pin; 14. Load; 15. Positioning groove; 16. Countersunk hole; 17. Lower ferrite substrate; 18. Upper ferrite substrate; 19. Ground plane; 20. Permanent magnet; 21. Temperature compensation plate; 22. Positioning pin. Detailed Implementation

[0032] The invention will now be further described with reference to the accompanying drawings.

[0033] Example 1: See Figures 1 to 6 A high-isolation dual-section circulator / isolator includes a cavity 1 with an open top. The cavity 1 includes two parallel and connected inner cavities. A central conductor 3 is provided in the inner cavity. A circuit board 4 is provided at the bottom of the cavity 1. The central conductor 3 includes three first pins 5 connected to the circuit board 4 and a second pin 6 connected to a load 14. The side wall of the cavity 1 is provided with three notches 7 for the first pins 5 to be inserted from top to bottom and through holes 8 for the second pins 6 to pass through from the inside to the outside.

[0034] The bottom of the cavity 1 is provided with two positioning protrusions 9, and the circuit board 4 is provided with two alignment holes 10 that match the positioning protrusions 9. The two positioning protrusions 9 are respectively located in the two alignment holes 10.

[0035] The three first pins 5 of the center conductor 3 are provided with a needle hole 11. The circuit board 4 is provided with a circuit board bottom hole 12 corresponding to the three needle holes 11. The three center needles 13 pass through the three needle holes 11 and the circuit board bottom hole 12 directly below them in sequence, and are soldered to the needle holes 11 and the circuit board bottom hole 12. The second pin 6 is bent upward to form the load 14 lead, and is soldered to the load 14 for conduction.

[0036] The two positioning bosses 9 are located directly below the two inner cavities in the cavity 1, respectively.

[0037] An assembly method for a high-isolation dual-section circulator / isolator includes the following steps;

[0038] (1) Process the center conductor 3;

[0039] A needle hole 11 is provided at the three first pins 5 of the center conductor 3, and the second pin 6 is bent to form the load 14 lead.

[0040] (2) Assemble cavity 1;

[0041] In the two inner cavities, the ferrite substrate 17, the center conductor 3, the upper ferrite substrate 18, the ground plane 19, the permanent magnet 20, the temperature compensation plate 21, and the cover plate 2 are stacked from bottom to top. Among them, the three first pins 5 of the center conductor 3 are located at the three notches 7, and the second pins 6 extend from the through hole 8.

[0042] (3) Select a positioning fixture. The upper surface of the positioning fixture is provided with a positioning groove 15. The inner wall shape of the positioning groove 15 matches and fits the outer wall shape of the circuit board 4. The positioning groove 15 is provided with two countersunk holes 16 for accommodating the positioning boss 9. The positioning groove 15 is also provided with at least 4 positioning pins 22. The position of each positioning pin 22 corresponds to a needle hole 11. When the positioning boss 9 is located in the countersunk hole 16, the positioning pin 22 passes through the needle hole 11 to position the center conductor 3.

[0043] (4) The soldering surface of the circuit board 4 is tinned. The whole obtained in step (3) is removed from the positioning fixture and its lower surface is in contact with the upper surface of the circuit board 4. The positioning boss 9 passes through the alignment hole 10 and is located in the countersunk hole 16. At this time, the three pin holes 11 at the three first pins 5 are exactly aligned with the three bottom holes of the circuit board.

[0044] (5) The three center pins 13 pass through the three pin holes 11 and the bottom hole 12 of the circuit board below them respectively, and solder is applied at the position where the center pins 13 pass through the pin holes 11 and the bottom hole 12 of the circuit board.

[0045] (6) The load 14 is attached to the outer wall of the cavity 1 and in contact with the load 14 lead. The contact point between the load 14 and the cavity 1 and the load 14 lead is tinned.

[0046] (7) Place the whole obtained in step (6) on a heating platform or reflow soldering, and wait for the solder to melt to complete the soldering.

[0047] In this invention, the center conductor 3 is connected to the circuit board 4 via the center pin 13. This structure reduces the bending process of the center conductor 3 during production and improves production efficiency.

[0048] This also avoids the risk of open circuit caused by improper bending of the center conductor 3 pin. If the center conductor 3 is not bent properly, the pin may lift up due to stress during soldering, potentially causing an open circuit.

[0049] Because the center conductor 3 is provided with a pin hole 11, and the center conductor 3 can be positioned well during assembly, the consistency of the return loss, isolation and insertion loss performance indicators of the three ports of the device can be well guaranteed.

[0050] This structure increases the batch yield rate of products from 80% to over 95%, which is beneficial for the mass production of devices.

[0051] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A high-isolation dual-section circulator / isolator, comprising an open-top cavity, the cavity including two parallel and communicating inner cavities, a central conductor disposed within the inner cavities, a circuit board disposed at the bottom of the cavity, the central conductor including three first pins connected to the circuit board and one second pin connected to a load, the sidewall of the cavity having three notches for inserting the first pins from top to bottom, and through holes for the second pins to pass through from the inside to the outside, characterized in that: The bottom of the cavity is provided with two positioning bosses, and the circuit board is provided with two alignment holes that match the positioning bosses. The two positioning bosses are respectively located in the two alignment holes. Each of the three first pins of the central conductor has a pin hole. Corresponding to the three pin holes, the circuit board has a bottom hole. The three central pins pass through the three pin holes and the bottom hole directly below them in sequence, and are soldered to the pin holes and the bottom hole. The second pin is bent upwards to form a load lead and soldered to the load for conductivity.

2. The high isolation dual-section circulator / isolator according to claim 1, characterized in that: The two positioning bosses are located directly below the two inner cavities in the cavity.

3. The assembly method of a high isolation dual-section circulator / isolator according to claim 1, characterized in that: Includes the following steps; (1) Process the center conductor; Needle holes are provided at the three first pins of the center conductor, and the second pins are bent to form load leads; (2) Assemble the cavity; Inside the two cavities, from bottom to top, a ferrite substrate, a center conductor, an upper ferrite substrate, a ground plane, a permanent magnet, a temperature compensation plate, and a cover plate are stacked sequentially. The three first pins of the center conductor are located at three notches, and the second pins extend from the vias. (3) Select a positioning fixture. The upper surface of the positioning fixture is provided with a positioning groove. The inner wall shape of the positioning groove matches and fits the outer wall shape of the circuit board. The positioning groove is provided with two countersunk holes for accommodating the positioning boss. The positioning groove is also provided with at least 4 positioning pins. The position of each positioning pin corresponds to a needle hole. When the positioning boss is located in the countersunk hole, the positioning pin passes through the needle hole to position the center conductor. (4) The soldering surface of the circuit board is tinned. The whole obtained in step (3) is removed from the positioning fixture and its lower surface is in contact with the upper surface of the circuit board. The positioning boss passes through the alignment hole and is located in the countersunk hole. At this time, the three pin holes at the three first pins are exactly aligned with the three bottom holes of the circuit board. (5) The three center pins pass through the three pin holes and the bottom hole of the circuit board below them respectively, and solder is applied at the position where the center pins pass through the pin holes and the bottom hole of the circuit board. (6) The load is attached to the outer wall of the cavity and in contact with the load lead. Tin is applied at the contact points between the load and the cavity and the load lead. (7) Place the whole obtained in step (6) on a heating platform or reflow soldering, and wait for the solder to melt to complete the soldering.

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