Isolator
Technical Field
The utility model relates to the technical field of isolator design and manufacture, in particular to an isolator.
Background
Along with the development of communication technology, the requirements on the isolator are higher and higher, for example, the isolator is required to be small in size and simple in procedure, and meanwhile, the requirement of high integration can be met; for example, the isolator generally adopts a symmetrical strip line structure of two gyromagnetic ferrite substrates, and for further miniaturization, a ferrite material substrate with high saturation magnetization strength and a high internal field can be adopted to reduce the plane size of the isolator, but the high internal field requires a permanent magnet to provide a stronger direct current magnetic field, so that the height of the device is higher, namely about 4mm; therefore, it is difficult to further reduce the device height in the current isolator design scheme without affecting the performance of the isolator and greatly increasing the planar size of the device.
Disclosure of Invention
In view of the above-described deficiencies of the prior art, the present utility model aims to: provided is a microminiature isolator capable of further reducing the device height without affecting the performance of the isolator and greatly increasing the planar size of the device.
In order to achieve the above object, the present utility model provides the following technical solutions:
an isolator, comprising: a magnetic shield case, a permanent magnet, a metal cavity, a center conductor, a gyromagnetic body substrate, a medium cavity, a magnetic circuit compensation sheet and a grounded metal cavity which are accommodated in the magnetic shield case; wherein,,
the medium cavity is clamped between the first metal cavity and the second metal cavity, the permanent magnet is arranged in the accommodating hole of the first metal cavity, and the magnetic circuit compensation sheet is arranged in the accommodating hole of the second metal cavity;
the central conductor is coated on the surface of the gyromagnetic body substrate and is arranged in the accommodating hole of the medium cavity together with the gyromagnetic body; and two ports of the three ports of the non-reciprocal junction formed by the center conductor are respectively connected with one port connecting piece, the port connecting piece is used as an input/output port to extend into the port window corresponding to the magnetic shielding shell, and one port is connected with a load.
In some possible embodiments, the center conductor includes a disk portion and three mesh inductances; and the disc part is attached to one surface of the gyromagnetic body substrate, the three grid inductors are respectively bent from the edge of the disc part to the other surface of the gyromagnetic body substrate along the side surface of the gyromagnetic body substrate, are staggered and overlapped on the gyromagnetic body substrate at an included angle of 120 degrees, and the end parts of the three grid inductors extend out of the gyromagnetic body substrate.
In some possible embodiments, the grid inductor stacked below the three grid inductors is closely attached to the gyromagnetic body substrate, and a layer of insulating medium is respectively arranged between the grid inductor stacked in the middle, the grid inductor stacked below the grid inductor and the grid inductor stacked above the grid inductor.
In some possible embodiments, the ground terminal of the grid inductor stacked above is provided with a strip-shaped metal connecting wire, so that the reflection coefficients of three ports of the non-reciprocal junction formed by the three grid inductors are basically the same by adjusting the length of the strip-shaped metal connecting wire.
In some possible embodiments, one end of the strip-shaped metal connecting wire is electrically connected to the ground terminal of the grid inductor stacked above, and the other end of the strip-shaped metal connecting wire is electrically connected to the second metal cavity; and the middle part of the strip-shaped metal connecting wire is arranged in a gap between the accommodating hole of the medium cavity and the gyromagnetic body substrate in a bending way.
In some possible embodiments, the ends of the three grid inductors are respectively connected with a port capacitor; and the port capacitor is arranged in a gap between the accommodating hole of the medium cavity and the gyromagnetic body substrate.
In some possible embodiments, one electrode of the port capacitor is electrically connected to an end of the mesh inductor and the other electrode is electrically connected to the second metal cavity; wherein,,
a grid inductor as a non-reciprocal junction port connected with the port connector, wherein a port connection conductor is formed at the end part of the grid inductor; the port connecting conductor comprises a circular ring part and a metal connecting pin extending outwards from the circular ring part; the metal connecting pin is electrically connected with the electrode of the port capacitor, and the circular ring part is electrically connected with the port connecting piece;
the port serving as the nonreciprocal junction is connected with the grid inductor of the load, and the end part of the grid inductor is provided with a metal connecting pin and is electrically connected with the electrode of the port capacitor through the metal connecting pin.
In some possible embodiments, three grooves are formed on one surface, which is attached to the first metal cavity, of the dielectric cavity, and the three grooves are used for respectively embedding three ports of a non-reciprocal junction formed by the three grid inductors; the medium cavity is provided with a through hole which is communicated with the corresponding lug boss at the bottom of the two grooves, and the port connecting piece is arranged in the through hole at the bottom of the groove and extends into the port windowing corresponding to the magnetic shielding shell together with the corresponding lug boss.
In some possible embodiments, the second metal cavity is provided with an avoidance opening for avoiding the boss.
In some possible embodiments, the grid inductance of the load is connected as a non-reciprocal junction port, the ends of which protrude through corresponding openings formed in the magnetic shield housing and are electrically connected to a load disposed on the magnetic shield housing.
In some possible embodiments, the magnetic shield housing comprises an upper U-shaped metal cover plate and a lower U-shaped metal cover plate that are snap-fit together in a staggered manner; and the upper U-shaped metal cover plate and the lower U-shaped metal cover plate are matched through a clamping groove to realize clamping.
In some possible embodiments, the lower U-shaped metal cover plate provides the port fenestration.
In some possible embodiments, the dielectric cavity is made of a ceramic material, and a grounded LC circuit is disposed within the dielectric cavity.
Compared with the prior art, the utility model has the beneficial effects that:
1. the isolator provided by the embodiment of the utility model adopts the single-sided permanent magnet to magnetize the gyromagnetic ferrite, and the magnetic circuit compensation sheet is added on the other side of the gyromagnetic ferrite substrate, so that a stronger uniform field is obtained inside the gyromagnetic ferrite substrate, and the height of the device is reduced on the premise of ensuring that the performance of the isolator is not influenced and the plane size of the device is greatly increased.
2. According to the isolator provided by the embodiment of the utility model, as the three grid inductances of the central conductor are different from the gyromagnetic ferrite substrate in contact state, the filling coefficients of the three grid inductances are different, and the reflection coefficients of the three ports are inconsistent, and the strip-shaped metal connecting wires are arranged at the grounding ends of the grid inductances overlapped above, so that the reflection coefficients of the three ports are basically identical by adjusting the lengths of the strip-shaped metal connecting wires, thereby ensuring the performance of the isolator.
3. According to the isolator provided by the embodiment of the utility model, the port connecting conductor is designed at the end part of the grid inductor, so that the connection of an input port and an output port can be realized, and the connection with a port capacitor can be realized; meanwhile, the port capacitor is arranged in a gap between the accommodating hole of the medium cavity and the gyromagnetic body substrate, and one electrode of the port capacitor is electrically connected to the grounded metal cavity, so that the problem that when the isolator is manufactured at present, the isolator is extremely easy to be subjected to environmental stress, particularly the effect of temperature stress due to the adoption of the three-dimensional welding port capacitor, the capacitor electrode at the welding point is caused to locally fall off, the port capacitance value is reduced, and the working frequency of the isolator is caused to drift is further solved; and in severe cases, the port capacitor is broken, and the isolator is disabled.
Drawings
FIG. 1 is an exploded schematic view of a magnetic shield housing, a first metal cavity, a dielectric cavity, and a second metal cavity of an isolator provided in an embodiment of the present utility model;
FIG. 2 is an exploded view of a permanent magnet, a center conductor, a gyromagnetic substrate and a magnetic circuit compensation sheet of an isolator provided in an embodiment of the present utility model;
FIG. 3 is a schematic view of an assembled configuration of an isolator provided in an embodiment of the present utility model;
FIG. 4 is a schematic diagram of an assembly structure of a center conductor and a gyromagnetic substrate of an isolator provided in an embodiment of the present utility model;
FIG. 5 is a schematic diagram of a dielectric cavity of an isolator according to an embodiment of the present utility model;
FIG. 6 is a schematic diagram of a second metal cavity of an isolator provided in an embodiment of the present utility model;
FIG. 7 is a top view of an assembled structure of a center conductor, gyromagnetic substrate, dielectric cavity, and second metal cavity of an isolator provided in an embodiment of the present utility model;
FIG. 8 is a schematic view of the assembly of the center conductor and gyromagnetic substrate shown in FIG. 4 with the addition of ribbon-shaped metal bond wires;
FIG. 9 is a schematic diagram of smith simulation results of an isolator according to the present utility model.
List of reference numerals
The magnetic circuit compensation device comprises a 1 a-upper U-shaped metal cover plate, a 1 b-lower U-shaped metal cover plate, a 2-first metal cavity, a 3-permanent magnet, a 4-gyromagnetic substrate, a 5-central conductor, a 6-medium cavity, a 7-magnetic circuit compensation sheet, an 8-second metal cavity, a 9-port connector, a 10-load, 11a, 11b, 11 c-port capacitance, a 51-disc part, 52a, 52b, 52 c-grid inductance, a 21-first metal cavity containing hole, a 61-medium cavity containing hole, 62a, 62b, 62 c-grooves, 63b, 63 c-through holes, 64b, 64 c-bosses, 81-second metal cavity containing holes, 82b, 82 c-avoidance holes, 520 a-ribbon metal connecting wires, 520b, 520 c-ring parts, 521a, 521b and 521 c-metal connecting pins.
Detailed Description
Other advantages and effects of the present utility model will become apparent to those skilled in the art from the following disclosure, which describes the embodiments of the present utility model with reference to specific examples. The utility model may be practiced or carried out in other embodiments that depart from the specific details, and the details of the present description may be modified or varied from the spirit and scope of the present utility model.
As shown in fig. 1, 2 and 3, the separator of the present utility model includes: a magnetic shield case, a permanent magnet 3, a first metal cavity 2, a center conductor 5, a gyromagnetic body substrate 4, a dielectric cavity 6, a magnetic circuit compensation sheet 7 and a second metal cavity 8 which are arranged in the magnetic shield case; wherein,,
the medium cavity 6 is clamped between the first metal cavity 2 and the second metal cavity 8, the permanent magnet 3 is arranged in the accommodating hole 21 of the first metal cavity 2, and the magnetic circuit compensation sheet is arranged in the accommodating hole of the second metal cavity;
the central conductor 5 is coated on the surface of the gyromagnetic body substrate 4 and is arranged in the accommodating hole 61 of the medium cavity 6 together with the gyromagnetic body substrate 4; and, of the three ports of the nonreciprocal junction formed by the center conductor 5, two ports are respectively connected to one port connector 9, and the port connector is extended into the port window corresponding to the magnetic shield case as an input/output port, and one port is connected to the load 10.
The isolator of the utility model adopts the single-sided permanent magnet to magnetize the gyromagnetic ferrite, and the magnetic circuit compensation sheet is added on the other side of the gyromagnetic ferrite substrate, so that the gyromagnetic ferrite substrate obtains a stronger uniform field, thereby reducing the height of the device on the premise of ensuring that the performance of the isolator is not influenced and the plane size of the device is greatly increased. Further, as shown in fig. 3, after the exploded structures of fig. 1 and 2 are assembled together, a surface-mounted separator can be obtained, while the external dimensions of the separator are not more than 5mm×5mm×2.5mm (length×width×height).
Specifically, in order to avoid the leakage of the direct-current magnetic field generated by the isolator and influence the performance of magnetic devices around the isolator, a corresponding magnetic shielding design is needed, namely, the magnetic shielding shell in the isolator comprises an upper U-shaped metal cover plate 1a and a lower U-shaped metal cover plate 1b which can be buckled together in a staggered manner; moreover, the upper U-shaped metal cover plate 1a and the lower U-shaped metal cover plate 1b are matched through clamping grooves to realize clamping, and port windowing corresponding to each port of the nonreciprocal junction formed by the central conductor 5 is arranged on the lower U-shaped metal cover plate 1 b. Meanwhile, the upper U-shaped metal cover plate 1a and the lower U-shaped metal cover plate 1b are made of metal materials.
Specifically, as shown in fig. 4, in the isolator of the present utility model, the gyromagnetic body substrate 4 is in a disc shape, and of course, those skilled in the art can design the gyromagnetic body substrate into other shapes, such as regular hexagon, etc., according to actual needs; the center conductor 5 includes a disc portion 51 and three mesh inductances 52a, 52b, 52c; the disc 51 is attached to one surface of the gyromagnetic body substrate 4, three grid inductors 52a, 52b, 52c are respectively bent from the edge of the disc 51 to the other surface of the gyromagnetic body substrate 4 along the side surface of the gyromagnetic body substrate 4, are stacked on the gyromagnetic body substrate 4 in a staggered manner at an included angle of 120 degrees, and the ends of the three grid inductors 52a, 52b, 52c extend out of the gyromagnetic body substrate 4.
Among the three mesh inductors 52a, 52b, and 52c, the mesh inductor 52c stacked below is closely attached to the gyromagnetic body substrate 4, and a layer of insulating medium is respectively disposed between the mesh inductor 52b stacked in the middle and the mesh inductor 52c stacked below and the mesh inductor 52a stacked above.
Referring to fig. 1, 3, 5 and 6 again, three grooves 62a, 62b and 62c are formed on the surface of the dielectric cavity 6, which is attached to the first metal cavity 2, and three bosses 64a, 64b and 64c are formed on the surface of the dielectric cavity 6, which is attached to the second metal cavity 8, at positions corresponding to the three grooves; wherein three grooves 62a, 62b, 62c are used to embed three ports of the non-reciprocal junction formed by three mesh inductors 52a, 52b, 52c, respectively. The bottoms of the grooves 62b, 62c are provided with through holes 63b, 63c penetrating the corresponding bosses 64b, 64c; the port connecting pieces 9 connected with the ends of the grid inductors 52b and 52c are arranged in the through holes 63b and 63c at the bottom of the groove, and the second metal cavity 8 is provided with avoidance holes 82b and 82c for avoiding the bosses 64b and 64c, so that the port connecting pieces 9 connected with the ends of the grid inductors 52b and 52c extend into the port windows corresponding to the lower U-shaped metal cover plate 1b of the magnetic shielding shell together with the corresponding bosses 64b and 64c and are flush with the bottom surface of the lower U-shaped metal cover plate 1b; the mesh inductor 52a has its end portion protruding out of a corresponding opening formed in the magnetic shield case and is electrically connected to the negative electrode 10 provided on the magnetic shield case.
In practice, the dielectric cavity 6 is made of ceramic material, and a grounded LC circuit is disposed in the dielectric cavity 6.
Specifically, as shown in fig. 7, in the isolator of the present utility model, three ports of the nonreciprocal junction formed by the three mesh inductors 52a, 52b, 52c are respectively connected to one port capacitor, namely, port capacitors 11a, 11b, 11c, and the port capacitors 11a, 11b, 11c are disposed in the gap between the accommodation hole 61 of the dielectric cavity 6 and the gyromagnetic body substrate 4 in order to control the height of the device. In other words, the aperture of the receiving hole 61 of the dielectric cavity 6 is longer than the outer diameter of the gyromagnetic body substrate 4 and slightly longer than the width of the port capacitance.
Meanwhile, one electrode of the port capacitor 11a, 11b, 11c is electrically connected to the end of the mesh inductor end 52a, 52b, 52c, and the other electrode is electrically connected to the second metal cavity 8. In practice, the aperture of the receiving hole 61 of the dielectric cavity 6 is longer than the aperture of the receiving hole 81 of the second metal cavity 8 and slightly longer than the width of the port capacitance. In this way, the port capacitors 11a, 11b, 11c can be directly placed on the surface of the second metal cavity 8, so that not only can the mounting stability of the port capacitors be ensured, but also the electrodes on the bottom surfaces of the port capacitors 10a, 10b, 10c can be directly electrically connected with the second metal cavity 8 to realize grounding.
Further, the port connection conductors formed at the ends of the mesh inductors 52b, 52c include circular ring portions 520b, 520c and metal connection pins 521b, 521c extending outward from the circular ring portions; the metal connection pins 521b and 521c are electrically connected to the electrodes on the top surfaces of the port capacitors 11b and 11c in a one-to-one manner, and the ring portions 520b and 520c are electrically connected to the port connection member 9 in a one-to-one manner. The mesh inductor 52a has a metal connection leg 521a formed at an end thereof, and is electrically connected to the electrode of the port capacitor 11a through the metal connection leg 521 a.
Therefore, the utility model can further solve the problems that when the isolator is manufactured at present, the three-dimensional welding port capacitor is extremely easy to be subjected to environmental stress, especially the effect of temperature stress, so that the capacitor electrode at the welding point is partially dropped off, the port capacitance value is reduced, and the working frequency of the isolator is shifted; and in severe cases, the port capacitor is broken, and the isolator is disabled.
Specifically, as shown in fig. 4 and fig. 7, since the mesh inductor 52c stacked below among the three mesh inductors 52a, 52b, and 52c is closely attached to the gyromagnetic body substrate 4, a layer of insulating medium is respectively provided between the mesh inductor 52b stacked in the middle and the mesh inductor 52c stacked below and the mesh inductor 52a stacked above. In practice, the mesh inductance 52c corresponding to the formed non-reciprocal junction port 1 is closely attached to the gyromagnetic ferrite substrate, and the mesh inductances 52b, 52c of the formed non-reciprocal junction ports 2 and 3 are separated from the gyromagnetic ferrite substrate by 1 layer and 2 layers of insulating medium, respectively, so that the contact states of the three mesh inductances 52a, 52b, 52c and the gyromagnetic substrate 4 are different, in other words, the filling coefficients of the three mesh inductances 52a, 52b, 52c are different. As can be seen from the smith simulation result shown in fig. 9a, there is a large deviation in reflection coefficient between the ports of the non-reciprocal junction formed by the three mesh inductors 52a, 52b, 52c, wherein the circuit of S11 is capacitive, does not converge around 50 ohms, the return loss is small compared to the other two ports S22, S33, and the insertion loss is large.
As shown in fig. 8, in order to solve the problem of large deviation of reflection coefficients between ports of the nonreciprocal junction, the isolator of the present utility model is provided with a strip-shaped metal connection line 520a at the ground end of the grid inductor stacked above, so that the reflection coefficients of three ports of the nonreciprocal junction formed by the three grid inductors 52a, 52b, 52c are substantially the same by adjusting the length of the strip-shaped metal connection line 520 a.
Specifically, one end of the strip-shaped metal connecting wire 520a 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 8; further, the middle portion of the strip-shaped metal connection wire 520a is provided in a bent manner in a gap between the accommodation hole of the dielectric cavity 6 and the gyromagnetic body substrate 4. As shown in the smith simulation result shown in fig. 9b, the deviation of the reflection coefficients between the ports of the nonreciprocal junctions formed by the three grid inductances 52a, 52b, 52c is obviously reduced, and the three ports S11, S22, S33 are converged to be close to 50 ohms, so that the loss of the isolator is less than 0.4dB, and the design requirement can be met.