A circulator

Abstract

The present invention discloses a circulator, which relates to the technical field of circulator design and manufacturing, and includes: a magnetic shielding shell, and a permanent magnet, a first metal cavity, a central conductor, a gyromagnetic substrate, a dielectric cavity, a magnetic circuit compensation sheet, and a second metal cavity, etc., which are arranged in the magnetic shielding shell. It uses a single-sided permanent magnet to magnetize the gyromagnetic ferrite, and adds a magnetic circuit compensation sheet on the other side of the gyromagnetic ferrite substrate, so that a strong uniform field is obtained inside the gyromagnetic ferrite substrate, thereby reducing the height of the device without affecting the performance of the circulator and greatly increasing the plane size of the device. By arranging a strip metal connecting line at the ground end of the grid inductor stacked on top, and adjusting the length of the strip metal connecting line, the reflection coefficients of the three ports are basically the same, thereby ensuring the performance of the circulator.

Description

Technical Field

[0001] The present invention relates to the technical field of circulator design and manufacturing, and in particular to a circulator. Background Art

[0002] A circulator is a non-reciprocal device with several ends. Since the circulator uses a gyromagnet made of gyromagnetic material, the gyromagnet can produce gyromagnetic properties under the combined action of an external microwave magnetic field and a constant DC magnetic field, causing the electromagnetic waves propagating in the gyromagnet to rotate in polarization, thereby realizing unidirectional transmission of high-frequency signal energy. For example, if a signal is input from port 1, the signal can only be output from port 2. Similarly, a signal input from port 2 can only be output from port 3, and so on. Therefore, it is called a circulator.

[0003] With the development of communication technology, the requirements for circulators are getting higher and higher. For example, the circulators are required to be small in size, simple in process, and able to adapt to the requirements of high integration. For example, circulators usually adopt a symmetrical stripline structure of two rotating magnetic ferrite substrates. To further achieve miniaturization, ferrite material substrates with high saturation magnetization intensity and high internal fields can be used to reduce the planar size of the circulator. However, since the high internal field requires permanent magnets to provide a strong DC magnetic field, the device height is relatively high, about 4 mm. Therefore, the current circulator design scheme is difficult to further reduce the device height without affecting the performance of the circulator and significantly increasing the planar size of the device. Summary of the invention

[0004] In view of the above-mentioned deficiencies in the prior art, an object of the present invention is to provide an ultra-small circulator that can further reduce the height of the device without affecting the performance of the circulator and significantly increasing the planar size of the device.

[0005] In order to achieve the above-mentioned invention object, the present invention provides the following technical solutions:

[0006] A circulator comprises: a magnetic shielding shell, and a permanent magnet, a metal cavity, a central conductor, a gyromagnetic substrate, a dielectric cavity, a magnetic circuit compensation sheet and a grounded metal cavity contained in the magnetic shielding shell; wherein:

[0007] The dielectric cavity is sandwiched between the first metal cavity and the second metal cavity, the permanent magnet is arranged in the receiving hole of the first metal cavity, and the magnetic circuit compensation sheet is arranged in the receiving hole of the second metal cavity;

[0008] The central conductor is coated on the surface of the gyromagnet substrate and is arranged together with the gyromagnet in the receiving hole of the dielectric cavity; moreover, each port of the non-reciprocal junction formed by the central conductor is respectively connected to a port connector, and the port connector is extended into the corresponding port window of the magnetic shielding shell as an input / output port.

[0009] In some possible embodiments, the central conductor includes a disk portion and three grid inductors; moreover, the disk portion is in contact with one side of the gyromagnetic substrate, and the three grid inductors are respectively bent from the edge of the disk portion along the side of the gyromagnetic substrate to the other side of the gyromagnetic substrate, and are alternately stacked on the gyromagnetic substrate at an angle of 120° to each other, and the ends of the three grid inductors all extend out of the gyromagnetic substrate.

[0010] In some possible embodiments, the grid inductor stacked at the bottom of the three grid inductors is arranged closely to the gyromagnetic substrate, and a layer of insulating medium is arranged between the grid inductor stacked in the middle and the grid inductor stacked at the bottom and the grid inductor stacked at the top.

[0011] In some possible embodiments, a strip metal connection line is provided at the ground end of the stacked grid inductor, so as to make the reflection coefficients of the three ports of the non-reciprocal junction formed by the three grid inductors substantially the same by adjusting the length of the strip metal connection line.

[0012] In some possible embodiments, one end of the strip metal connecting wire is electrically connected to the ground terminal of the grid inductor stacked above, and the other end thereof is electrically connected to the second metal cavity; moreover, the middle portion of the strip metal connecting wire is bent and arranged in the gap between the accommodating hole of the dielectric cavity and the gyromagnetic substrate.

[0013] In some possible embodiments, the ends of the three mesh inductors are respectively connected to a port capacitor; and the port capacitor is disposed in a gap between the receiving hole of the dielectric cavity and the gyromagnetic substrate.

[0014] In some possible embodiments, one electrode of the port capacitor is electrically connected to the second metal cavity, and the other electrode is electrically connected to a port connection conductor formed at an end of the mesh inductor.

[0015] In some possible embodiments, the port connection conductor includes a circular ring portion and a metal connection pin extending outward from the circular ring portion; wherein the metal connection pin is electrically connected to the electrode of the port capacitor, and the circular ring portion is electrically connected to the port connector.

[0016] In some possible embodiments, one side of the dielectric cavity that is in contact with the first metal cavity is provided with three grooves connected to its accommodating holes, and one side of the dielectric cavity that is in contact with the second metal cavity is formed with three bosses at positions corresponding to the three grooves; wherein the three grooves are used to respectively embed three ports of the non-reciprocal junction formed by the three grid inductors, and the bottom of the groove is provided with a through hole that passes through the corresponding boss, and the port connector is arranged in the through hole at the bottom of the groove, and extends into the port window corresponding to the magnetic shielding shell together with the corresponding boss.

[0017] In some possible embodiments, the second metal cavity is provided with three avoidance openings for avoiding the boss.

[0018] In some possible embodiments, the magnetic shielding shell includes an upper U-shaped metal cover plate and a lower U-shaped metal cover plate that can be interlaced and buckled together; and the upper U-shaped metal cover plate and the lower U-shaped metal cover plate are clamped together by cooperating in a clamping groove.

[0019] In some possible embodiments, the lower U-shaped metal cover plate is provided with the port window.

[0020] In some possible embodiments, the dielectric cavity is made of ceramic material, and a grounded LC circuit is disposed in the dielectric cavity.

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

[0022] 1. The circulator provided in the embodiment of the present invention uses a single-sided permanent magnet to magnetize the gyromagnetic ferrite, and adds a magnetic circuit compensation sheet on the other side of the gyromagnetic ferrite substrate, so that a strong uniform field is obtained inside the gyromagnetic ferrite substrate, thereby reducing the height of the device without affecting the performance of the circulator and greatly increasing the planar size of the device.

[0023] 2. The circulator provided in the embodiment of the present invention has different filling coefficients of the three grid inductors of the central conductor and the gyromagnetic ferrite substrate due to their different contact states, which leads to inconsistent reflection coefficients of the three ports. By providing a strip metal connecting line at the ground end of the grid inductor stacked above and adjusting the length of the strip metal connecting line, the reflection coefficients of the three ports are made basically the same, thereby ensuring the performance of the circulator.

[0024] 3. The circulator provided in the embodiment of the present invention has a port connection conductor designed at the end of the grid inductor, which can realize the connection between the input and output ports and the port capacitor; at the same time, the port capacitor is set in the gap between the accommodating hole of the dielectric cavity and the gyromagnetic substrate, and one electrode of the port capacitor is electrically connected to the grounded metal cavity, which can further solve the problem that when manufacturing the circulator currently, the port capacitor is easily affected by environmental stress, especially temperature stress, due to the use of three-dimensional welding. The capacitor electrode at the welding point is partially detached, the port capacitance value is reduced, and the working frequency of the circulator drifts; in severe cases, the port capacitor is ruptured, causing the circulator to fail. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is an exploded schematic diagram of a magnetic shielding shell, a first metal cavity, a dielectric cavity and a second metal cavity of a circulator provided in an embodiment of the present invention;

[0026] Figure 2 It is an exploded schematic diagram of the permanent magnet, the central conductor, the gyromagnetic substrate and the magnetic circuit compensation sheet of the circulator provided in the embodiment of the present invention;

[0027] Figure 3 A schematic diagram of the assembly appearance of a circulator provided in an embodiment of the present invention;

[0028] Figure 4 It is a schematic diagram of the assembly structure of the central conductor and the gyromagnetic substrate of the circulator provided in an embodiment of the present invention;

[0029] Figure 5 A schematic structural diagram of a dielectric cavity of a circulator provided in an embodiment of the present invention;

[0030] Figure 6 A schematic diagram of the structure of a second metal cavity of a circulator provided in an embodiment of the present invention;

[0031] Figure 7 A top view of the assembly structure of the central conductor, gyromagnetic substrate, dielectric cavity and second metal cavity of the circulator provided in an embodiment of the present invention;

[0032] Figure 8 for Figure 4 A schematic diagram of a structure in which a strip-shaped metal connecting line is added to the assembly structure of the central conductor and the gyromagnetic substrate shown;

[0033] Fig. 9 It is a schematic diagram of the Smith simulation results of the circulator of the present invention.

[0034] Reference numerals list

[0035] 1a-upper U-shaped metal cover, 1b-lower U-shaped metal cover, 2-first metal cavity, 3-permanent magnet, 4-gyromagnetic substrate, 5-center conductor, 6-dielectric cavity, 7-magnetic circuit compensation plate, 8-second metal cavity, 9-port connector, 10a, 10b, 10c-port capacitor, 11-strip metal connecting line, 51-disk portion, 52a, 52b, 52c-grid inductor, 21-accommodating hole of the first metal cavity, 61-accommodating hole of the dielectric cavity, 62a, 62b, 62c-groove, 63a, 63b, 63c-through hole, 64a, 64b, 64c-boss, 81-accommodating hole of the second metal cavity, 82a, 82b, 82c-avoidance hole, 520a, 520b, 520c-annular portion, 521a, 521b, 521c-metal connecting foot. DETAILED DESCRIPTION

[0036] The following describes the embodiments of the present invention through specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention.

[0037] like Figure 1 and Figure 2 As shown, the circulator of the present invention comprises: a magnetic shielding shell, and a permanent magnet 3, a first metal cavity 2, a central conductor 5, a gyromagnetic substrate 4, a dielectric cavity 6, a magnetic circuit compensation sheet 7 and a second metal cavity 8 arranged in the magnetic shielding shell; wherein,

[0038] The dielectric cavity 6 is sandwiched between the first metal cavity 2 and the second metal cavity 8, the permanent magnet 3 is arranged in the receiving hole 21 of the first metal cavity 2, and the magnetic circuit compensation sheet is arranged in the receiving hole of the second metal cavity;

[0039] The central conductor 5 is coated on the surface of the gyromagnetic substrate 4, and is arranged together with the gyromagnetic substrate 4 in the receiving hole 61 of the dielectric cavity 6; moreover, each port of the non-reciprocal junction formed by the central conductor 5 is respectively connected to a port connector 9, and the port connector 9 is extended into the corresponding port opening of the magnetic shielding shell as an input / output port.

[0040] Since the circulator of the present invention uses a single-sided permanent magnet to magnetize the gyromagnetic ferrite and adds a magnetic circuit compensation sheet on the other side of the gyromagnetic ferrite substrate, a strong uniform field is obtained inside the gyromagnetic ferrite substrate, thereby reducing the height of the device without affecting the performance of the circulator and greatly increasing the planar size of the device. Figure 3 As shown, Figure 1 and Figure 2 After the decomposed structures are assembled together, a surface-mount circulator can be obtained, and the outer dimensions of the circulator are not greater than 5mm×5mm×2.5mm (length×width×height).

[0041] Specifically, in order to avoid leakage of DC magnetic field generated by the circulator and affect the performance of magnetic devices around the circulator, a corresponding magnetic shielding design is required, that is, the magnetic shielding shell in the circulator of the present invention includes an upper U-shaped metal cover plate 1a and a lower U-shaped metal cover plate 1b that can be interlaced and buckled together; and the upper U-shaped metal cover plate 1a and the lower U-shaped metal cover plate 1b are clamped together through the engagement of the clamping groove, and the lower U-shaped metal cover plate 1b is provided with port openings corresponding to the ports of the non-reciprocal junction formed by the central conductor 5. At the same time, the upper U-shaped metal cover plate 1a and the lower U-shaped metal cover plate 1b are both made of metal materials.

[0042] Specifically, Figure 4 As shown, in the circulator of the present invention, the gyromagnetic substrate 4 is in the shape of a disc. Of course, those skilled in the art can design the gyromagnetic substrate into other shapes, such as a regular hexagon, according to actual needs; the central conductor 5 includes a disc portion 51 and three grid inductors 52a, 52b, and 52c; moreover, the disc portion 51 is in contact with one side of the gyromagnetic substrate 4, and the three grid inductors 52a, 52b, and 52c are respectively bent from the edge of the disc portion 51 along the side of the gyromagnetic substrate 4 to the other side of the gyromagnetic substrate 4, and are alternately stacked on the gyromagnetic substrate 4 at an angle of 120° to each other, and the ends of the three grid inductors 52a, 52b, and 52c all extend out of the gyromagnetic substrate 4.

[0043] Among the three mesh inductors 52a, 52b, 52c, the mesh inductor 52c stacked at the bottom is closely arranged on the gyromagnetic substrate 4, and a layer of insulating medium is arranged between the mesh inductor 52b stacked in the middle, the mesh inductor 52c stacked at the bottom and the mesh inductor 52a stacked at the top.

[0044] Recombination Figure 1 and Figure 5Three grooves 62a, 62b, and 62c are provided on one side of the dielectric cavity 6 that is in contact with the first metal cavity 2, and three bosses 64a, 64b, and 64c are formed on one side of the dielectric cavity 6 that is in contact with the second metal cavity 8 and at positions corresponding to the three grooves; wherein the three grooves 62a, 62b, and 62c are used to respectively embed three ports of the non-reciprocal junction formed by the three mesh inductors 52a, 52b, and 52c. Moreover, through holes 63a, 63b, 63c which penetrate the corresponding three bosses 64a, 64b, 64c are provided at the bottom of the three grooves 62a, 62b, 62c; the port connector 9 for connecting the three ports of the non-reciprocal junction formed by the three mesh inductors 52a, 52b, 52c is arranged in the through holes 63a, 63b, 63c at the bottom of the groove, and the second metal cavity 8 is provided with three avoidance openings 82a, 82b, 82c for avoiding the bosses. In this way, the port connector for connecting the three ports of the non-reciprocal junction formed by the three mesh inductors 52a, 52b, 52c, together with the corresponding three bosses 64a, 64b, 64c, extends into the port opening corresponding to the lower U-shaped metal cover plate 1b of the magnetic shielding shell, and is flush with the bottom surface of the lower U-shaped metal cover plate 1b.

[0045] In implementation, the dielectric cavity 6 is made of ceramic material, and a grounded LC circuit is arranged in the dielectric cavity 6 .

[0046] Specifically, Figure 7 As shown, the three ports of the non-reciprocal junction formed by the three mesh inductors 52a, 52b, 52c in the circulator of the present invention are respectively connected to a port capacitor, namely, port capacitors 10a, 10b, 10c, and, in order to control the height of the device, the port capacitors 10a, 10b, 10c are arranged in the gap between the receiving hole 61 of the dielectric cavity 6 and the gyromagnetic substrate 4. In other words, the diameter of the receiving hole 61 of the dielectric cavity 6 is longer than the outer diameter of the gyromagnetic substrate 4, and slightly longer than the width of the port capacitor.

[0047] At the same time, one electrode of the port capacitor 10a, 10b, 10c is electrically connected to the second metal cavity 8, and the other electrode is electrically connected to the port connection conductor formed by the mesh inductor ends 52a, 52b, 52c. In implementation, the caliber of the receiving hole 61 of the dielectric cavity 6 is longer than the caliber of the receiving hole 81 of the second metal cavity 8, and slightly longer than the width of the port capacitor. In this way, the port capacitors 10a, 10b, 10c can be placed directly on the surface of the second metal cavity 8, which can not only ensure the installation stability of the port capacitor, but also the electrodes on the bottom of the port capacitors 10a, 10b, 10c can be directly electrically connected to the second metal cavity 8 to achieve grounding.

[0048] Moreover, the port connecting conductor formed at the end of the grid inductor 52a, 52b, 52c includes annular portions 520a, 520b, 520c and metal connecting pins 521a, 521b, 521c extending outward from the annular portions; wherein the metal connecting pins 520a, 520b, 520c are electrically connected one-to-one to the electrodes on the top surfaces of the port capacitors 10a, 10b, 10c, and the annular portions 520a, 520b, 520c are electrically connected one-to-one to the three port connectors 9.

[0049] In this way, the present invention can further solve the problem that when currently manufacturing circulators, due to the use of three-dimensional welded port capacitors, the circulators are extremely susceptible to environmental stress, especially temperature stress, which causes partial detachment of capacitor electrodes at the solder joints, reduces the port capacitance value, and causes the operating frequency of the circulator to drift; in severe cases, the port capacitors are ruptured, causing the circulator to fail.

[0050] Specific, combined Figure 4 and Figure 7 As shown, among the three mesh inductors 52a, 52b, 52c, the mesh inductor 52c stacked at the bottom is closely attached to the gyromagnetic substrate 4, and a layer of insulating medium is respectively arranged between the mesh inductor 52b stacked in the middle and the mesh inductor 52c stacked at the bottom and the mesh inductor 52a stacked at the top. In fact, the mesh inductor 52c of port 1, which is equivalent to the formed non-reciprocal junction, is closely attached to the gyromagnetic ferrite substrate, while the mesh inductors 52b and 52c of ports 2 and 3, which are formed by the formed non-reciprocal junction, are separated from the gyromagnetic ferrite substrate by 1 layer and 2 layers of insulating medium, respectively. In this way, the contact states of the three mesh inductors 52a, 52b, 52c and the gyromagnetic substrate 4 are different. In other words, the filling coefficients of the three mesh inductors 52a, 52b, 52c are different. According to the Fig. 9 From the Smith simulation results shown in a, it can be seen that there is a large deviation in the reflection coefficient between the ports of the non-reciprocal junction formed by the three mesh inductors 52a, 52b, and 52c. Among them, the circuit of S11 is capacitive and does not converge near 50 ohms. The return loss is smaller than that of the other two ports S22 and S33, and the insertion loss is larger.

[0051] like Figure 8 As shown, in order to solve the problem of large deviation in reflection coefficient between ports of non-reciprocal junction, the circulator of the present invention is provided with a strip metal connecting line 11 at the ground end of the grid inductor stacked above, so as to make the reflection coefficients of the three ports of the non-reciprocal junction composed of three grid inductors 52a, 52b, and 52c substantially the same by adjusting the length of the strip metal connecting line 11.

[0052] Specifically, one end of the strip metal connecting wire 11 is electrically connected to the ground end of the grid inductor stacked on top, and the other end is electrically connected to the second metal cavity 8; and the middle part of the strip metal connecting wire 11 is bent and arranged in the gap between the receiving hole of the dielectric cavity 6 and the gyromagnetic substrate 4. After adding the strip metal connecting wire 11, according to the following example, Fig. 9 From the Smith simulation results shown in b, it can be seen that the deviation of the reflection coefficient between the ports of the non-reciprocal junction formed by the three mesh inductors 52a, 52b, and 52c is significantly reduced, with a certain symmetry. The three ports S11, S22, and S33 all converge near 50 ohms, making the loss of the circulator less than 0.4dB, which can meet the design requirements.

Claims

1. A circulator, characterized in that: include: A magnetic shielding shell, and a permanent magnet, a first metal cavity, a central conductor, a gyromagnetic substrate, a dielectric cavity, a magnetic circuit compensation sheet and a second metal cavity arranged in the magnetic shielding shell; wherein, The dielectric cavity is sandwiched between the first metal cavity and the second metal cavity, the permanent magnet is arranged in the receiving hole of the first metal cavity, and the magnetic circuit compensation sheet is arranged in the receiving hole of the second metal cavity; The central conductor is coated on the surface of the gyromagnet substrate and is disposed together with the gyromagnet in the receiving hole of the dielectric cavity; moreover, each port of the non-reciprocal junction formed by the central conductor is respectively connected to a port connector, and the port connector is extended into the corresponding port window of the magnetic shielding shell as an input / output port; Moreover, the central conductor includes a disc portion and three mesh inductors, the disc portion is in contact with one side of the gyromagnetic substrate, the three mesh inductors are respectively bent from the edge of the disc portion along the side of the gyromagnetic substrate to the other side of the gyromagnetic substrate, and are alternately stacked on the gyromagnetic substrate at an angle of 120°, and the ends of the three mesh inductors all extend out of the gyromagnetic substrate; The grid inductor stacked at the bottom of the three grid inductors is closely arranged with the gyromagnetic substrate, and a layer of insulating medium is respectively arranged between the grid inductor stacked in the middle and the grid inductor stacked at the bottom and the grid inductor stacked at the top; The grounding end of the grid inductor stacked on top is provided with a strip metal connection line, so as to make the reflection coefficients of the three ports of the non-reciprocal junction formed by the three grid inductors the same by adjusting the length of the strip metal connection line; One end of the strip metal connecting wire is electrically connected to the ground end of the grid inductor stacked above, and the other end is electrically connected to the second metal cavity; moreover, the middle part of the strip metal connecting wire is bent and arranged in the gap between the accommodating hole of the dielectric cavity and the gyromagnetic substrate.

2. A circulator as claimed in claim 1, characterized in that: The ends of the three mesh inductors are respectively connected to a port capacitor; and the port capacitor is arranged in the gap between the receiving hole of the dielectric cavity and the gyromagnetic substrate.

3. A circulator as claimed in claim 2, characterized in that: One electrode of the port capacitor is electrically connected to the second metal cavity, and the other electrode is electrically connected to a port connection conductor formed at an end of the mesh inductor.

4. A circulator as claimed in claim 3, characterized in that: The port connection conductor includes a circular ring portion and a metal connection pin extending outward from the circular ring portion; wherein the metal connection pin is electrically connected to the electrode of the port capacitor, and the circular ring portion is electrically connected to the port connector.

5. A circulator as claimed in claim 4, characterized in that: The side of the dielectric cavity that is in contact with the first metal cavity is provided with three grooves, and the side of the dielectric cavity that is in contact with the second metal cavity is formed with three bosses at positions corresponding to the three grooves; wherein the three grooves are used to respectively embed three ports of the non-reciprocal junction formed by the three grid inductors.

6. A circulator as claimed in claim 5, characterized in that: A through hole is provided at the bottom of the groove to penetrate the corresponding boss, and the port connector is arranged in the through hole at the bottom of the groove and extends into the corresponding port window of the magnetic shielding shell together with the corresponding boss; The second metal cavity is provided with three avoidance openings for avoiding the boss; The magnetic shielding shell comprises an upper U-shaped metal cover plate and a lower U-shaped metal cover plate which can be interlaced and buckled together; and the upper U-shaped metal cover plate and the lower U-shaped metal cover plate are clamped together by means of a clamping groove; The lower U-shaped metal cover plate is provided with the port opening; The dielectric cavity is made of ceramic material, and a grounded LC circuit is arranged in the dielectric cavity.

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