JPH0946104A - Irreversible circuit element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To position a permanent magnet with high precision without increasing the number of components and without causing deterioration in the electric characteristics and the workability. SOLUTION: Plural conductors 9 are arranged in a metallic case 6 crossing with each other in an electric non-contact state and a permanent magnet 5 is arranged in the case 6 to apply a DC magnetic field to the crossing part of the conductors 6 to form a circulator 1, then the permanent magnet 5 is in press contact with a ceiling wall 6a of the metallic case 6 and a corner ridge 5b of the permanent magnet 5 is engaged with a corner ridge 6c of the metallic case 6 and positioned and fixed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a non-reciprocal circuit device, such as an isolator or a circulator, which is adopted as a microwave band high frequency circuit component.

[0002]

2. Description of the Related Art For example, microwave lumped constant type isolators and circulators have characteristics that the damping force is extremely small in the signal transmission direction and extremely large in the opposite direction. It is used in the transmission circuit section. As an example of such an isolator,
For example, there is a structure proposed in Japanese Patent Application No. 5-143575. As shown in FIG. 12, the isolator 50 described above is used.
Arranges the electrode substrate 53 and the permanent magnet 54 in the pair of metal cases 51, 52, and
Thus, a DC magnetic field is applied to the electrode substrate 53. The electrode substrate 53 is configured by arranging three conductors 55 ... In an electrically insulated state and intersecting at a predetermined angle, and a ferrite 56 is brought into contact with the intersecting portion of each conductor 55. Reference numeral 57 is a capacitor substrate, 58 is a matching circuit capacitor chip, and 59 is a termination resistor chip.

In the isolator 50, a resin block 60 is used to match the center of the permanent magnet 54 with the centers of the conductors 55 and the ferrite 56 for the purpose of improving the electrical characteristics. This resin block 60
Comprises a positioning hole 60a into which the permanent magnet 54 is inserted and a positioning recess 60b into which the electrode substrate 53 and the capacitor substrate 57 are mounted.

As a conventional mounting structure for the permanent magnet, as shown in FIG. 10, a protruding piece 65a is formed by cutting and raising the ceiling wall of a metal case 65.
There is one that fixes the permanent magnet 66. Further, FIG.
As shown in FIG. 3, there is a metal case 67 in which a mesh-shaped unevenness 67a is cut out on the inner surface of the ceiling wall to improve the adhesive strength between the permanent magnet and the metal case 67 (Japanese Patent Application No. Hei 10-135242). 1-141022).

[0005]

However, the conventional positioning structure using the resin block has a problem in that although the accuracy is high, the size of the entire component increases and the cost increases as the number of components increases.

Further, in the above-mentioned structure in which the permanent magnet is fixed by the protrusions and the concavo-convex portions of the metal case, it is possible to reduce the size and cost as compared with the resin block, but the positioning accuracy is low and desired electrical characteristics are obtained. May not be obtained. Further, in the above-mentioned conventional structure for forming the protruding piece, when the metal case is a magnetic body, the magnetic field is apt to be disturbed by the protruding piece, and the electrical characteristics may be deteriorated. Furthermore, in the above conventional structure for forming the uneven portion, a step of applying an adhesive is required, and the workability is low, and
There is a problem that the reliability of the adhesive against deterioration with time is low.

On the other hand, when the permanent magnet is fixed to the metal case, if the side surfaces of the two magnets come into contact with each other, the N pole and the S pole are directly connected to each other, so that they are magnetically short-circuited. As a result, the magnetic field distribution is likely to vary, and the applied magnetic force may be weakened, and improvement in this respect is required.

The present invention has been made in view of the above conventional situation, and the permanent magnet can be accurately positioned without increasing the number of parts and without causing deterioration of electrical characteristics and deterioration of workability, and It is an object of the present invention to provide a non-reciprocal circuit device that can make the magnetic field distribution uniform and avoid a decrease in applied magnetic force.

[0009]

According to a first aspect of the present invention, a plurality of conductors are arranged in a metal case in an electrically non-contact state so as to intersect with each other, and a DC magnetic field is applied to the intersecting portions of the conductors. In a nonreciprocal circuit device in which a permanent magnet is arranged, the permanent magnet is brought into contact with the inner surface of the top wall of the metal case, and the corner edge of the permanent magnet on the top wall side is formed by the top wall and the side wall of the metal case. It is characterized in that the permanent magnet is positioned in the direction perpendicular to the axis by engaging with the formed corner edge.

Here, it is general to use a disc-shaped permanent magnet and a quadrilateral metal case for the above-mentioned permanent magnet, but in the present invention, the permanent magnet is quadrangular or polygonal. , Or a metal case made into a disc shape or a polygon shape in accordance with the shape of the permanent magnet.

According to a second aspect of the present invention, in the same nonreciprocal circuit device as the first aspect, a positioning protrusion is integrally formed on the inner surface of the top wall of the metal case, and the permanent magnet is engaged with the protrusion. The feature is that a concave portion is formed.

The invention of claim 3 is characterized in that an inclined surface is formed on either or both of the inner surface of the side wall of the metal case and the side peripheral surface of the permanent magnet to avoid contact between the both.

According to a fourth aspect of the present invention, one or both of the inner surface of the side wall of the metal case and the side peripheral surface of the permanent magnet is coated with a non-contact film made of a non-magnetic material or a diamagnetic material. It is characterized by having done.

[0014]

According to the first aspect of the present invention, since the corner edge of the permanent magnet is engaged with the corner edge of the inner wall of the metal case, the movement of the permanent magnet in the direction orthogonal to the axis is restricted, so that positioning and fixing can be performed accurately. As a result, electrical characteristics can be improved. As a result, it is possible to eliminate the need for conventional positioning with a resin block, avoid an increase in the size of parts, and reduce the cost of parts.
Further, since the permanent magnet is positioned by engaging with the inner wall of the metal case, it is not necessary to cut and raise the protruding piece and cut out the uneven portion as in the prior art. It also solves the problems of workability deterioration and deterioration over time.

According to the second aspect of the present invention, since the concave portion of the permanent magnet is engaged with the convex portion formed on the inner surface of the top wall of the metal case to position and fix it, the positional accuracy can be improved and the electrical characteristics can be improved. Similarly, it is possible to avoid an increase in the size of parts and reduce the cost. Further, since the convex portion is integrally formed on the metal case, the disturbance of the magnetic field can be reduced as compared with the conventional case of cutting and raising or notching.

According to the third aspect of the present invention, since the inclined surface is formed on the inner surface of the side wall of the metal case and the side surface of the permanent magnet so as to avoid contact between them, magnetic short circuit due to contact can be prevented, and the direction of the magnetic force line is centered accordingly. The magnetic field can be concentrated, the magnetic field distribution can be made uniform, and the applied magnetic force can be improved.

According to the fourth aspect of the present invention, since the non-contact film made of the non-magnetic material or the diamagnetic material is formed on the inner surface of the side wall of the metal case and the side surface of the permanent magnet, even if they are brought close to each other, they are magnetic. A short circuit can be prevented, the magnetic field distribution can be made uniform, and the applied magnetic force can be improved. Further, since the permanent magnet can be brought into contact with the side surface of the metal case through the non-contact film, the ferrite facing area of the permanent magnet can be secured by that much, and the magnetic field distribution can be further homogenized.

[0018]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the accompanying drawings. 1 and 2 are views for explaining a circulator according to an embodiment of the invention of claims 1 and 3, FIG. 1 is a sectional view of the circulator, and FIG. 2 is an exploded perspective view of the circulator.

In the figure, reference numeral 1 denotes a lumped constant type circulator used in the microwave band, which has a ground plate 3 disposed on a bottom wall 2a of a lower case 2 made of a magnetic metal and a multi-layer substrate 4 mounted thereon. The permanent magnet 5 is arranged on the multilayer substrate 4, and the upper case 6 also made of magnetic metal is attached to the lower case 2.

Protrusions 7, 7 are integrally formed on both ends of the lower surface of the multilayer substrate 4, and the protrusions 7 protrude below the lower case 2. External connection electrodes 8 serving as input / output terminals and ground terminals are formed on the outer surface of each of the projections 7, and each external connection electrode 8 is surface-mounted on an electrode line of a circuit board (not shown). .

The multi-layer substrate 4 is formed by laminating a large number of rectangular ceramic green sheets (not shown) having a thickness of several to several tens of μm, and integrally sintering these. Three center conductors 9 are embedded inside the multilayer substrate 4, and the respective center conductors 9 are alternately positioned in an electrically insulated state with the green sheet sandwiched therebetween, and have an angle of 120 degrees with each other. They are arranged to intersect each other.

Inside the multi-layer substrate 4, there are buried a capacitance electrode (not shown) to which one end of each of the central conductors 9 is connected and a ground electrode to which the other end is connected. The ground electrode is connected to each of the external connection electrodes 8 described above. These electrodes are connected to each other through through-hole electrodes, and the central conductor 9, the capacitance electrode, and the ground electrode are patterned on the ceramic green sheet by printing, vapor deposition, or the like.

Each of the central conductors 9 on the lower surface of the multilayer substrate 4
The concave portion 4a is formed in the portion facing the concave portion 4a.
The ferrite 10 is inserted and arranged therein, whereby the ferrite 10 is positioned and fixed. The upper surface of the ferrite 10 faces the intersecting portion of the central conductors 9 and the lower surface thereof contacts the ground plate 3.

The upper case 6 has a substantially box-like shape in which side walls 6b are formed by bending side walls of a quadrangular ceiling wall 6a, and the permanent magnets 5 are arranged in the upper case 6. 5, a DC magnetic field is applied to the intersection of the central conductors 9. The permanent magnet 5 has a disk shape, and the side peripheral surface 5a thereof is inclined inward to form a substantially truncated cone shape. As a result, a gap a for avoiding a magnetic short circuit is provided between the inclined side peripheral surface 5a and the inner surface of each side wall 6b of the upper case 6.

The upper edge 5b of the permanent magnet 5 is the upper case 6
Is in contact with a square edge 6c formed by the top wall 6a and the side wall 6b, and the upper surface of the permanent magnet 5 is soldered to the top wall 6a. As a result, the permanent magnet 5 is positioned and fixed to the upper case 6, and the center of the permanent magnet 5 coincides with the center of each central conductor 9 and the ferrite 10.

The operation and effect of this embodiment will be described. According to the circulator 1 of the present embodiment, since the upper edge 5b of the permanent magnet 5 is engaged with the corner edge 6c of the upper case 6, the movement of the permanent magnet 5 in the diametrical direction is restricted, Positioning and fixing can be performed with high accuracy by simple mounting work, and electrical characteristics can be improved. As a result, the conventional resin block can be eliminated, and the entire component can be downsized and the component cost can be reduced.

Further, since the upper edge 5b of the permanent magnet 5 and the corner edge 6c of the upper case 6 are brought into contact and engaged with each other at four positions for positioning, the conventional protruding piece is cut and raised or the uneven portion is formed. It is not necessary to cut out, it is possible to avoid the characteristic deterioration due to the disturbance of the magnetic field, the application work of the adhesive can be eliminated, and further the deterioration of the reliability due to the deterioration of the adhesive with time can be solved.

In this embodiment, the side peripheral surface 5 of the permanent magnet 5 is used.
Since a is formed in an inclined shape, a gap a for preventing a magnetic short circuit can be formed between the side peripheral surface 5a and the inner surface of the side wall 6b of the upper case 6 even at the above-described four contact engagement positions. The direction of the lines of magnetic force can be concentrated in the center, the magnetic field distribution can be made uniform, and the applied magnetic force can be improved.

FIG. 3 is a characteristic diagram showing the results of an experiment conducted to confirm the effect of the above embodiment. In this experiment, the lines of magnetic force at the lower surface position of the permanent magnet 5 having the inclined side peripheral surface 5a (see a'in FIG. 3) and the ferrite position below the permanent magnet 5 (see b'in FIG. 3) were measured. The distribution state was measured. Further, for comparison, the distribution state of the lines of magnetic force was measured at the lower surface position (see a in FIG. 3) and the ferrite position (see b in FIG. 3) of the permanent magnet having the conventional structure.

As is apparent from FIG. 3, when the side peripheral surface 5a of the permanent magnet 5 is formed in an inclined shape, the direction of the lines of magnetic force is concentrated in the center as a whole and the applied magnetic force is increased as compared with the conventional structure. It can be seen that the magnetic field distribution is improved.

In the above embodiment, the upper edge 5b of the permanent magnet 5 is engaged with the corner edge 6c of the upper case 6 for positioning and fixing, and the side peripheral surface 5b of the permanent magnet 5 is formed in an inclined shape. Although the description has been given by taking the case where the magnetic short circuit is prevented as an example, the present invention is not limited to this. 4 to 6 are views for explaining a magnetic short circuit preventing structure according to a modification of the above embodiment. In each figure, the same reference numerals as those in FIG. 1 indicate the same or corresponding parts.

In FIG. 4, the upper edge 5b of the permanent magnet 5 is engaged with the corner edge 6c of the upper case 6 to position and fix it, and the side walls 6b of the upper case 6 are inclined outward in a skirt shape to make them permanent. In this example, a gap a is provided between the magnet 5 and the magnet 5 to prevent a magnetic short circuit. Also in this example, the positioning can be performed with high accuracy, the magnetic field distribution can be made uniform, and the applied magnetic force can be improved, and the same effect as that of the above-described embodiment can be obtained.

FIG. 5 shows the top wall 6a and the side wall 6 of the upper case 6.
An inclined portion 6d is formed at a bent portion with respect to b, and an upper edge 5b of the permanent magnet 5 is engaged with an inner corner edge 6c of the inclined portion 6d to position and fix the permanent magnet 5 and the permanent magnet 5 and the side wall 6b. This is an example in which a gap a for preventing a magnetic short circuit is provided therebetween. Also in this example, the positioning accuracy can be improved and the magnetic field distribution can be made uniform, and the same effect as that of the above-described embodiment can be obtained.
Further, since the inclined portion 6d is formed on the upper case 6, the effect of facilitating the application of solder when joining the upper case 6 and the lower case 2 and facilitating the flow of the solder to the joining surface is obtained. The inclined portion 6d may be formed over the entire circumference of the upper case 6 or may be formed partially. Further, the inclined portion 6d may be formed in a round shape.

FIG. 6 shows that the upper edge 5b of the permanent magnet 5 has a lower portion 5c.
A flange portion 5d having a larger diameter is integrally formed in a stepped shape, and an outer peripheral surface and an upper edge 5b of the flange portion 5d are engaged with the side wall 6b and the corner edge 6c of the upper case 6 to position and fix the lower portion 5c. In this example, a gap a for preventing a magnetic short circuit is provided between the side wall 6b and the side wall 6b. In this example, the same effect as that of the above-described embodiment can be obtained.

FIG. 7 is a diagram for explaining one embodiment of the invention of claim 2, in which the same reference numerals as those in FIG. 1 indicate the same or corresponding parts.

In this embodiment, a positioning projection 6e is integrally formed on the inner surface of the top wall 6a of the upper case 6, and a recess 5e for engaging with the projection 6e is provided on the upper surface of the permanent magnet 5. Is configured. In this embodiment, the recess 5 of the permanent magnet 5 is used.
The permanent magnet 5 can be accurately positioned and fixed only by fitting e into the convex portion 6e of the upper case 6. Further, since the convex portion 6e is formed on the upper case 6 in a protruding manner, the disturbance of the magnetic field can be reduced and the deterioration of the electrical characteristics can be avoided as compared with the case where the conventional protruding piece is cut and raised.

FIG. 8 is a diagram for explaining one embodiment of the invention of claim 4, in which the same reference numerals as those in FIG. 1 indicate the same or corresponding portions.

In this embodiment, the non-contact film 20 made of a non-magnetic material or a diamagnetic material is formed on the side peripheral surface 5f of the permanent magnet 5.
Is formed by plating, coating or the like. The side peripheral surface 5f of the permanent magnet 5 is in contact with the side wall 6b of the upper case 6 with the non-contact film 20 interposed therebetween, and the upper edge 5b of the permanent magnet 5 is aligned with the corner edge 6c of the upper case 6. Engaged.

In this embodiment, since the non-contact film 20 is formed on the side peripheral surface 5f of the permanent magnet 5, magnetic short circuit can be prevented, and the same effect as in the above embodiment can be obtained. Further, since the non-contact film 20 is formed, the diameter dimension of the permanent magnet 5 can be increased to the inside of the upper case 6, and the homogenization of the magnetic field distribution is further improved as compared with the case where the inclined surface is formed on the permanent magnet. it can.

FIG. 9 is a characteristic diagram showing the result of an experiment conducted to confirm the effect of the embodiment of FIG. In this experiment, the distribution state of the lines of magnetic force at the lower surface position of the permanent magnet 5 on which the non-contact film 20 is formed (see a ′ in FIG. 9) and the ferrite position below the permanent magnet 5 (see b ′ in FIG. 9) is measured. did. For comparison, the distribution state of the lines of magnetic force was measured at the lower surface position (see a in FIG. 9) and the ferrite position (see b in FIG. 9) of the permanent magnet having the conventional structure.

In FIG. 9, when the non-contact film is formed on the permanent magnet (a ', b'), the applied magnetic force is slightly reduced as the side surface of the permanent magnet approaches the upper case, but the diameter of the permanent magnet is reduced. Since it can be increased, it can be seen that the magnetic field distribution is made more uniform and the electrical characteristics are improved.

In each of the above-mentioned embodiments, the circulator has been described as an example, but the present invention can of course be applied to an isolator and also to other high frequency circuit components exhibiting an irreversible function.

[0043]

As described above, in the invention according to claim 1,
Since the corner edge of the permanent magnet is engaged with the corner edge of the inner wall of the metal case for positioning and fixing, the invention according to claim 2 is further characterized in that a positioning projection is integrally formed on the inner surface of the top wall of the metal case, and Since the concave part that engages with the convex part is formed, there is an effect that the permanent magnet can be positioned and fixed with high accuracy, the size increase of the part can be avoided and the part cost can be reduced, and the characteristic deterioration due to the disturbance of the magnetic field and the aging There is an effect that the problem of deterioration can be solved.

According to the third aspect of the present invention, since the inclined surface is formed on the inner surface of the side wall of the metal case or the side surface of the permanent magnet so as to avoid contact between the both, the inner surface of the side wall of the metal case or the permanent surface is formed. Since the non-contact film made of non-magnetic material or diamagnetic material is coated on the side surface of the magnet, magnetic short circuit can be prevented and the magnetic field distribution can be made uniform.
There is an effect that the applied magnetic force can be improved.

[Brief description of drawings]

FIG. 1 is a sectional view for explaining a circulator according to an embodiment of the invention of claims 1 and 3.

FIG. 2 is an exploded perspective view of the circulator.

FIG. 3 is a characteristic diagram showing an effect of the circulator.

FIG. 4 is a schematic configuration diagram showing a circulator according to another example of the embodiment.

FIG. 5 is a schematic configuration diagram showing a circulator according to another example of the embodiment.

FIG. 6 is a schematic configuration diagram showing a circulator according to another example of the embodiment.

FIG. 7 is a schematic configuration diagram for explaining an embodiment of the invention of claim 2;

FIG. 8 is a schematic configuration diagram for explaining an embodiment of the invention of claim 4;

FIG. 9 is a characteristic diagram showing the effect of the above-described embodiment.

FIG. 10 is an exploded perspective view showing a conventional permanent magnet positioning structure.

FIG. 11 is a perspective view showing a conventional positioning structure.

FIG. 12 is an exploded perspective view showing a conventional general circulator.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Circulator (non-reciprocal circuit element) 5 Permanent magnet 5a Inclined side peripheral surface 5b Upper edge (corner edge) 5e Recess 6 Upper case (metal case) 6c Corner edge 6e Projection 9 Center conductor 20 Non-contact film

Claims (4)

[Claims] 1. A nonreciprocal circuit device comprising a plurality of conductors arranged in an electrically insulated state and intersecting each other in a metal case, and a permanent magnet for applying a DC magnetic field disposed at the intersections of the conductors. , The permanent magnet is brought into contact with the inner surface of the top wall of the metal case, and the corner edge of the permanent magnet on the top wall side is engaged with the corner edge formed by the top wall and the side wall of the metal case. A non-reciprocal circuit device characterized in that the magnet is positioned in a direction perpendicular to the axis. 2. A nonreciprocal circuit device having a plurality of conductors arranged in a non-contact state and intersecting each other in a metal case, and a permanent magnet for applying a DC magnetic field at the intersection of the conductors. 2. A nonreciprocal circuit device according to claim 1, wherein a positioning protrusion is integrally formed on the inner surface of the top wall of the metal case, and a recess that engages with the protrusion is formed in the permanent magnet. 3. The inclined surface according to claim 1 or 2, wherein an inclined surface is formed on either or both of the inner surface of the side wall of the metal case and the side peripheral surface of the permanent magnet to avoid contact between the both. Non-reciprocal circuit element. 4. The non-contact film made of a non-magnetic material or a diamagnetic material on either or both of the inner surface of the side wall of the metal case and the side circumferential surface of the permanent magnet according to claim 1. A non-reciprocal circuit device characterized by being formed by coating.