JPH04355502A - Irreversible circuit element - Google Patents

Abstract

PURPOSE:To make the component small and the weight light by making the diameter of a ferrite small while ensuring a required inductance of a center conductor sufficiently and to realize the irreversible circuit element in which the productivity is improved through the simplified assembly of the said center conductor. CONSTITUTION:Plural 1st center conductors 40 arranged in crossing in the electric insulation state are insert-formed to a resin block 33, a 2nd center conductor 41 is integrally formed to one end 40a of each 1st center conductor 40, a lower face 38b of a ferrite 38 is abutted to a crossing part of each of the 1st center conductors 40 and each of 2nd center conductors 41 are folded and arranged to an upper face 38a of the ferrite 38 while keeping electric insulation.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention relates to nonreciprocal circuit elements used as high-frequency components in the microwave band, such as isolators and circulators, and in particular, the present invention relates to nonreciprocal circuit elements used as high-frequency components in the microwave band, such as isolators and circulators. The present invention relates to a structure that can be made smaller and lighter, and that can simplify the assembly work of the center conductor and improve productivity.

0002

[Prior Art] In general, lumped constant type isolators and circulators have the function of having almost no attenuation in the signal transmission direction and large attenuation in the opposite direction.For example, they are used in mobile phones, automobiles, etc. It is used in the transmitter circuits of mobile communication devices such as telephones. Conventionally, such isolators and circulators have a plurality of central conductors 1 made of metal arranged in an electrically insulated state with an insulating sheet interposed therebetween and crossed at, for example, 120°, as shown in FIG. 10(a). A pair of ferrites 2,
2 are brought into contact with each other, a ground plate 3 is arranged on the outer surface of each ferrite 2, and a DC magnetic field is applied to the ferrite 2 by a permanent magnet. Also, Figure 10
As shown in (b), there is also a structure in which a single ferrite 2 is brought into contact with the intersection of the center conductor 1. By the way, the above-mentioned conventional structure has a problem of low productivity because it is a time-consuming task of sandwiching an insulating sheet between each center conductor 1 while intersecting the center conductors 1 alternately. . Conventionally, there are structures as shown in FIGS. 7 to 9 to improve this time-consuming work. The structure shown in FIG. 7 has a structure in which a center conductor 5 and an insulating film 6 are alternately formed on the upper surface of the ferrite 4, and a ground plate 7 is brought into contact with the lower surface of the ferrite 4. Furthermore, in the case shown in FIG. 8, a center conductor 5 and an insulating film 6 are alternately formed on the upper surface of an insulating substrate 8, the substrate 8 is sandwiched between a pair of ferrites 9, and each ferrite 9 is grounded. It has a structure in which a plate 10 is brought into contact with it. Furthermore, in the case shown in FIG. 9(a), the center conductor 11 is divided into first and second conductor parts 11a and 11b, and the first conductor part 11a is arranged on the upper surface of the insulating substrate 12, and the upper surface of this A structure in which a second conductor part 11b is arranged with an insulating sheet 13 interposed between the two, and the tips of the first and second conductor parts 11a and 11b are connected to each other through a connection hole formed in the insulating sheet 13. (See Japanese Patent Publication No. Sho 62-11802). Furthermore, in the case shown in FIG. 9(b), a part 15a of the center conductor 15 is patterned on one main surface of the insulating substrate 14, and a remaining part 15b of the center conductor 15 is patterned on the other main surface, It has a structure in which both 15a and 15b are connected by a through-hole electrode 16 formed in an insulating substrate 14 (see Japanese Patent Publication No. 33344/1983). According to each of the above structures, since each center conductor is formed by printing, vapor deposition, etc., productivity can be improved compared to the structure in which the above-mentioned center conductors are alternately crossed and an insulating sheet is sandwiched between them.

0003

[Problems to be Solved by the Invention] When the above-mentioned isolators and circulators are used in, for example, mobile phones, there is a demand for smaller and lighter parts due to their use. In order to meet such demands, it is effective, for example, to make the diameter of the ferrite as small as possible. However, in each of the above conventional structures, when the diameter of the ferrite is reduced, it becomes difficult to secure the necessary inductance of the center conductor.
As a result, there is a problem of deterioration of electrical characteristics. That is, the inductance value is determined by the length of the center conductor, and this length is determined by the diameter value of the ferrite. Therefore, the smaller the ferrite diameter, the shorter the effective length of the center conductor, and the smaller the inductance value. Here, in order to secure the inductance value, it is possible to narrow the electrode width of the center conductor, but in this case, the Q of the center conductor decreases, and as shown in FIG. 6, when the Q decreases, the isolator A problem arises in that the insertion loss of the circulator increases.

Therefore, the inventors of the present invention have devised a nonreciprocal circuit element that can maintain the inductance value of the center conductor even if the diameter of the ferrite is reduced, as shown in FIGS. 4 and 5. This is done by bending the center conductor 20 into a substantially U-shape, and forming each center conductor 20 on both main surfaces 21a and 21b of the ferrite 21.
The center conductors 20 are mounted so as to be in contact with each other in the diametrical direction, and each center conductor 20 is interposed with an insulating sheet 22 interposed therebetween at intervals of 120 degrees. According to this structure, since the center conductor 20 is wound around both main surfaces 21a and 21b of the ferrite 21, the diameter of the ferrite can be reduced by increasing the effective length of the center conductor 20. Can be made lighter. However, in the above structure, the productivity is low because it requires a complicated assembly work in which each center conductor 20 is attached to the ferrite 21 while crossing each other, and the insulating sheet 22 is sandwiched between each center conductor 20. Improvements are requested.

The present invention has been made in view of the above circumstances, and makes it possible to reduce the size and weight of the ferrite by reducing the diameter of the ferrite without deteriorating its electrical characteristics, and to improve productivity by simplifying the assembly work of the center conductor. The purpose of this invention is to provide a nonreciprocal circuit element that can be used.

[0006]

[Means for Solving the Problems] The invention as claimed in claim 1 provides that a second center conductor is connected to one end of a plurality of first center conductors that are arranged in an electrically insulated state and intersect with each other at predetermined angular intervals. integrally extended, one main surface of the ferrite is brought into contact with the intersection of each of the first center conductors, and the second center conductor is electrically insulated from the other main surface of the ferrite,
The non-reciprocal circuit element is characterized in that the non-reciprocal circuit element is bent and arranged so as to face the first central conductor. Further, the invention according to claim 2 is characterized in that the intersection portion of the first center conductor is embedded in the resin block by insert molding.

[0007]

[Operation] According to the non-reciprocal circuit element according to the invention of claim 1, the second central conductor is integrally formed at one end of the plurality of first central conductors, and a ferrite layer is formed at the intersection of each of the first central conductors. Since the main surfaces are in contact with each other and the second center conductor is bent and arranged on the other main surface of the ferrite, the effective length of the center conductor is longer than that of the conventional structure in which the center conductor is formed only on one side of the ferrite. Therefore, it is possible to reduce the diameter of the ferrite while ensuring a sufficient inductance value of the center conductor, which in turn makes it possible to reduce the size and weight of parts. Also,
When assembling the center conductor, after arranging the ferrite at the intersection of the first center conductor, the second center conductor is bent and placed on the top surface of the ferrite, so the above-mentioned integrally formed center conductor is attached to the ferrite. This process is simpler than the work of inserting an insulating sheet at the same time, and productivity can be improved accordingly. Moreover, in the invention of claim 2, since the first center conductor is inserted into the resin block, the assembly work of the center conductor can be further simplified.

[0008]

Embodiments Hereinafter, embodiments of the present invention will be explained with reference to the drawings. 1 and 2 are diagrams for explaining a nonreciprocal circuit element according to an embodiment of the present invention. In this embodiment, a case where the present invention is applied to a lumped constant isolator will be explained. In the figure, 30 is an isolator to which the structure of this embodiment is applied. This isolator 30 has a grounding plate 32 disposed on the bottom surface 31a of a lower yoke 31 made of magnetic metal, a rectangular parallelepiped resin block 33 disposed above the grounding plate 32, and a magnetic An upper yoke 34 made of body metal is attached to form a magnetic closed circuit, and a permanent magnet 35 is bonded to the lower surface of the upper yoke 34, so that a DC magnetic field is applied by the permanent magnet 35.

A circular recess 33a with a bottom is formed in the center of the upper surface of the resin block 33, into which a ferrite 38 is inserted. Three insertion holes 33b are formed penetrating the peripheral edge of the recess 33a of the resin block 33 at predetermined angular intervals, and a rectangular parallelepiped matching circuit chip capacitor 36 is provided in each insertion hole 33b. is inserted. One electrode 36a of each chip capacitor 36 is connected to the ground plate 32, and the other electrode 36b
is located on the upper surface of the resin block 33. Further, an insertion hole 33c is similarly formed in the vicinity of one insertion hole 33b of the resin block 33, and a terminating resistor 37 is inserted into the insertion hole 33c. One electrode 37a of this terminating resistor 37 is connected to the ground plate 32, and the other electrode 37b is located on the upper surface of the resin block 33. Note that ground terminals 32a, 32a are integrally formed on the ground plate 32, and each ground terminal 32a is connected to the opening 34a of the upper yoke 34.
It protrudes outward from the

Further, input and output terminals 3 are provided on the upper surfaces of the two chip capacitors 36 on the resin block 33, respectively.
8 are arranged at the base 38 of each input and output terminal 38.
a is connected to the other electrode 36b of the chip capacitor 36. Furthermore, the tip portions 38b of each of the input and output terminals 38 protrude outward from the opening 34a of the upper yoke 34. Further, a termination resistor terminal 39 is arranged on the upper surface of the termination resistor 37 adjacent to the remaining chip capacitor 36, and the resistor terminal 39 is connected to the other electrodes 36b, 37b of both 36, 37. There is.

[0011] Then, the recess 33 of the resin block 33
Three first center conductors 40 made of metal plates are buried in the recess 33a by insert molding so that their upper surfaces are exposed at the bottom of the recess 33a, and the center conductors 40 form an angle of 120 degrees with each other. They are arranged in a criss-cross pattern. Further, the mutually abutting surfaces of the intersecting portions of each of the first central conductors 40 are coated with an insulating film 42, so that each of the central conductors 40 is electrically insulated. A second central conductor 41 is integrally extended from one end 40a of each of the first central conductors 40, and each central conductor 41 is led out upward from the side surface of the recess 33a. Further, the other end portion 40b of each first center conductor 40 is connected to a resin block 33.
It is exposed on the lower surface and connected to the ground plate 32.

[0012] Also, the recess 33a of the resin block 33
A disk-shaped ferrite 38 is inserted inside, and the lower surface 38b of the ferrite 38 is in contact with the intersection of the first central conductor 40. Further, on the upper surface 38a of the ferrite 38, each of the second central conductors 41 is bent so as to intersect every 120 degrees.
The center conductor 41 is composed of the first center conductor 40 and the ferrite 38.
They are facing each other with the two sides in between. Further, the mutually abutting surfaces of the second central conductors 41 are coated with an insulating film 42, so that the second central conductors 41 are electrically insulated. Furthermore, each of the second center conductors 4
The tip end 41a of 1 is connected to the base 38 of each input and output terminal 38 mentioned above.
a, and the upper surface of the terminal 39 for terminating resistor by soldering or spot welding.

Next, the effects of this embodiment will be explained. According to the isolator 30 of this embodiment, each first center conductor 40 is buried in the recess 33a of the resin block 33, and the lower surface 38 of the ferrite 38 is placed at the intersection of the center conductors 40.
b is brought into contact with the upper surface 38 of the ferrite 38.
Since each of the second center conductors 41 is bent and arranged at the point a, the effective length of the first and second center conductors 40 and 41 that come into contact with the ferrite 38 can be increased, and the inductance value of the center conductors can be increased accordingly. The diameter of the ferrite 38 can be reduced without deteriorating the electrical characteristics, and the parts can be made smaller and lighter. In addition, Fig. 2(a) and Fig. 2(b)
), in order to assemble each of the center conductors 40 and 41, each first center conductor 40 is inserted into the resin block 33 in advance, and the ferrite 38 is inserted into the recess 33a of the resin block 33. After that, it is only necessary to bend the second center conductor 41, which eliminates the need for the complicated assembly work of interposing an insulating sheet while attaching the center conductor bent in a U-shape to the ferrite as described above. , productivity can be improved. moreover,
In this embodiment, the ferrite 38 is inserted into the resin block 33 by an automatic machine, and each second center conductor 41 can be bent and arranged on the upper surface of the ferrite 38, and the chip capacitors 36 and the terminating resistor 37 can be arranged in sequence. mass production is possible. This makes it possible to provide a high-performance, inexpensive isolator with less variation in mechanical and electrical characteristics.

Note that in the above embodiment, the first central conductor 40
The explanation has been given by taking as an example the case where the resin block 33 is inserted into the resin block 33.
As shown in FIG. 3, the ferrite 38 is arranged with the first center conductors 40 arranged in a cross-like manner, and the second center conductors 41 are bent and arranged on the upper surface 38a of the ferrite 38 to form an assembly 45. You can. In this case, the size and weight can be further reduced by eliminating the need for resin blocks. Further, in the above embodiment, the contact surfaces of the center conductors 40 and 41 are coated with the insulating film 42, but in the present invention, an insulating sheet may be inserted and arranged. Furthermore, in the above embodiment,
Although the case where the present invention is applied to an isolator has been taken as an example, the present invention can of course also be applied to a circulator.

[0015]

As described above, according to the non-reciprocal circuit element according to the invention of claim 1, the second central conductor is integrally formed at one end of the plurality of first central conductors, and Bringing one main surface of the ferrite into contact with the intersection, and bending and arranging the second center conductor on the other main surface of the ferrite,
Further, in the invention of claim 2, since the first center conductor is formed as an insert in the resin block, the effective length of the center conductor that contacts the ferrite can be increased, and therefore the diameter of the ferrite can be reduced while ensuring a sufficient inductance value. This has the effect of reducing the size and weight of parts, as well as simplifying the assembly work of the center conductor and improving productivity.

[Brief explanation of the drawing]

FIG. 1 is an exploded perspective view for explaining an isolator according to an embodiment of the present invention.

FIG. 2 is a diagram showing a procedure for assembling the center conductor of the above embodiment.

FIG. 3 is a diagram showing another example of the ferrite assembly of the above embodiment.

FIG. 4 is a perspective view for explaining the process of establishing the present invention.

FIG. 5 is a schematic configuration diagram for explaining the process of establishing the present invention.

FIG. 6 is a characteristic diagram showing the relationship between the Q value of the center conductor and the insertion loss.

FIG. 7 is an exploded perspective view showing an assembled structure of a conventional ferrite and a center conductor.

FIG. 8 is an exploded perspective view showing an assembled structure of a conventional ferrite and a center conductor.

FIG. 9 is a perspective view showing the structure of a conventional center conductor.

FIG. 10 is a schematic configuration diagram showing a conventional ferrite assembly.

[Explanation of symbols]

30 Isolator (irreciprocal circuit element) 38 Ferrite 38a, 38b Upper and lower surfaces of ferrite (both principal surfaces)
40 First center conductor 40a One end portion of the first center conductor 41 Second center conductor

Claims (2)

[Claims] Claim 1: A second central conductor is integrally extended and formed at one end of a plurality of first central conductors which are arranged in an electrically insulated state and intersect with each other at predetermined angular intervals; One main surface of the ferrite is brought into contact with the intersection of the center conductors, and the second center conductor is bent and placed on the other main surface of the ferrite so as to be electrically insulated and facing the first center conductor. A non-reciprocal circuit element characterized by: 2. The irreversible circuit element according to claim 1, wherein the intersection portions of the first center conductors are embedded in a resin block by insert molding.