JPH0936610A - Irreversible circuit element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To simplify the constitution to reduce the number of connection points between parts, to resolve short-circuit and conduction defects, and to reduce the size and the cost. SOLUTION: A ferrite 12 and a matching capacity 13 of >=90% dielectric constant are mounted on a magnetic yoke 11 used as the earth. A center conductor 14 consisting of an approximately Y-shaped strip conductor is connected to this matching capacity, and the end part is connected to an input/output terminal 15 of a pedestal 17. A ground terminal 16 of the pedestal is connected to the magnetic yoke 11. A permanent magnet 18 is placed on the pedestal and is covered with a magnetic yoke 19 and gives a magnetic field stronger than the resonance magnetic field to the ferrite. In the case of the use as an isolator, a terminating resistance 20 is connected between the input/output terminal 15 and the earth terminal.

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, and more particularly to a non-reciprocal circuit device used in microwave communication equipment, mobile communication equipment and the like.

[0002]

2. Description of the Related Art A conventional lumped-constant type nonreciprocal circuit device, as shown in FIG.
Printed circuit boards 33, 34, and 35, and matching capacitance 36
a, 36b, and 36c, the terminating resistor 37, and the case 3
8, permanent magnets 39a and 39b, and magnetic yoke 40a
And 40b.

The center conductor 31 is composed of a plurality of strip conductors 4.
1, and these strip conductors 41 are laminated in a state of being insulated from each other so that their extending directions are equiangularly spaced. Then, the central conductor 31 is mounted and connected to the printed board 33 in which the ferrite 32 is housed in the through hole 42.

The printed circuit board 33 is laminated on the printed circuit boards 34 and 35 and electrically connected thereto. Printed circuit board 3
4, matching capacitors 36a, 36b, and 36c and a terminating resistor 37 are connected. By connecting the printed circuit board 33 in layers, the matching capacitance and the terminating resistor are connected to the strip conductor 41.

The printed circuit boards 33, 34, and 35 on which the central conductor 31 and the ferrite 32 are mounted are housed in a case 38, and the input / output terminal 4 arranged in the case 38.
3 and the ground terminal 44. As a result, one end of the strip conductor 41 is connected to the input / output terminal 43,
The other end is connected to the ground terminal 44.

The permanent magnets 39a and 39b and the magnetic yokes 40a and 40b are mounted above and below the case 38 so as to form a closed magnetic circuit for applying a DC magnetic field to the central conductor 31 and the ferrite 32. Has been.

[0007]

The central conductor used in the conventional lumped-constant type nonreciprocal circuit device is formed by, for example, forming a mesh on a double-sided printed circuit board or laminating a plurality of printed circuit boards. can get. But in any case,
Since a plurality of strip conductors must be laminated in an insulated state, there is a problem that the structure is complicated and the cost is high.

Further, in order to connect one end of the strip line to the input / output terminal and the other end to the ground terminal, the printed board on which the central conductor is mounted requires electrode patterns of the number of central conductors × 2. In order to cope with SMD, these electrode patterns must be formed in a narrow area of 7 mm × 7 mm under the present circumstances, and problems such as short circuit and poor conduction are apt to occur when ensuring conduction by paste solder or the like. There is a problem.

Further, there is a distributed constant type non-reciprocal circuit device having a simpler structure than the above lumped constant type non-reciprocal circuit device.
Usually, the distributed constant nonreciprocal element is used in the frequency range of the S band (2 to 4 GHz) or higher, and the ferrite needs to be large in order to be used in the L band or lower (1 to 2 GHz).
There is a problem that it is not suitable for miniaturization.

It is an object of the present invention to provide a small-sized and low-cost nonreciprocal circuit device that simplifies the structure, reduces the number of connection points between components, and is free from short circuits and defective conduction.

[0011]

According to the present invention, a center conductor having a plurality of input / output terminals, a ferrite superposed on the center conductor, and a plurality of matching capacitors respectively connected to the plurality of input / output terminals. And a permanent magnet for applying a magnetic field to the ferrite, and a magnetic yoke for forming a closed magnetic circuit, in a nonreciprocal circuit device, wherein the central conductor has a plurality of conductor portions radially extending at equal angular intervals. It is a single strip conductor and the matching capacitance has a dielectric constant of 90.
A nonreciprocal circuit device having the above-mentioned dielectric is obtained.

Further, according to the present invention, the magnetic yoke is used as an earth by mounting the ferrite and a matching capacitor arranged around the ferrite, and the permanent magnet is applied to the ferrite by a resonance magnetic field thereof. A non-reciprocal circuit device is obtained which is characterized in that a strong magnetic field is applied.

Furthermore, according to the present invention, a nonreciprocal circuit device is obtained in which the ferrite is one disk-shaped ferrite.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows an embodiment of the present invention. The lumped-constant nonreciprocal circuit device according to the present embodiment includes a magnetic yoke 11 also serving as a ground, a ferrite 12 mounted on the magnetic yoke 11, and a matching capacitor 13 made of a dielectric material having the same thickness as the ferrite 12. The center conductor 14 placed on the ferrite 12, the pedestal 17 on which the input / output terminal 15 and the ground terminal 16 are arranged, and the permanent magnet 1 placed on the pedestal 17.
8 and a magnetic yoke 19 that covers the permanent magnet 18 and forms a closed magnetic circuit together with the magnetic yoke 11.

The center conductor 14 is substantially Y-shaped and is formed so that the angles formed by the conductor portions adjacent to each other are equal. When the center conductor 14 is placed on the ferrite 12, the center conductor 14 is connected to the matching capacitance 13 at a predetermined position near the tip of each conductor portion. In addition, the center conductor 14
The tips of the conductor portions of are connected to the input / output terminals 15 arranged on the pedestal 17, respectively.

The ferrite 12 has, for example, ΔH ≦ 50, and the matching capacitor 13 is made of a dielectric material having a dielectric constant ε = 90 or more in order to make the entire size equivalent to that of the conventional lumped constant type. I was there. In this embodiment, since the matching capacitance 13 is arranged around the center conductor 14 and the ferrite 12, it is possible to increase the equivalent dielectric constant and slow the propagation speed. The size of the non-reciprocal circuit device can be almost the same. For example, 1.5
The ferrite of the nonreciprocal circuit device of this example corresponding to GHz had a diameter of 4.0 mm. By the way, 1.5G
The dimension of the ferrite of the distributed constant type nonreciprocal circuit device corresponding to Hz is 13.5 mm in diameter.

The input / output terminal 15 and the ground terminal 16 arranged on the pedestal 17 are formed so as to correspond to the SMD. The ground terminal 16 is electrically connected to the magnetic yoke 11. If a terminating resistor 20 is connected between the ground terminal 16 and the input / output terminal 15, this nonreciprocal circuit element functions as an isolator.

The permanent magnet 18 is composed of magnetic yokes 11 and 19.
The magnetic field is placed in the closed magnetic circuit formed by and a DC magnetic field is applied to the ferrite 12. In this embodiment, the number of parts can be reduced and the device can be made thin by using a single ferrite structure. Here, the permanent magnet 18 is the ferrite 12
A magnetic field stronger than the resonance magnetic field is applied to the. If the magnetic field applied to the ferrite is stronger than the saturation magnetic field of the ferrite, this nonreciprocal element circuit exhibits stable temperature characteristics. Further, when it is weaker than the saturation magnetic field, it is difficult to obtain stable temperature characteristics, but it is possible to realize miniaturization.

The frequency characteristic of the nonreciprocal circuit device of this embodiment is shown by a solid line, and the frequency characteristic of the conventional concentrated nonreciprocal circuit device is shown by a broken line in FIG.

In this embodiment, an example in which one ferrite and one permanent magnet are provided has been described, but if the external dimensions permit, these may be two and the central conductor may be sandwiched.

[0021]

According to the present invention, by using a substantially Y-shaped strip conductor as the center conductor, the manufacturing process of the center conductor can be simplified and the number of connection points can be reduced. Further, miniaturization can be realized by using a dielectric having a dielectric constant of 90 or more.

Further, since the magnetic yoke is used as the ground, the ferrite and the matching capacitor are mounted on the magnetic yoke, and the center conductor is connected to the matching capacitor, a plurality of printed circuit boards and the like are required. A non-reciprocal circuit device having a simple structure can be obtained. As a result, the steps such as soldering can be reduced, the cost can be reduced, and the number of defective products can be reduced.

[Brief description of drawings]

FIG. 1 is an exploded perspective view of one embodiment of the present invention.

FIG. 2 is a graph showing frequency characteristics of the nonreciprocal circuit device of FIG.

FIG. 3 is an exploded perspective view of a conventional lumped constant nonreciprocal circuit device.

[Explanation of symbols]

 11 magnetic yoke 12 ferrite 13 matching capacitance 14 center conductor 15 input / output terminal 16 earth terminal 17 pedestal 18 permanent magnet 19 magnetic yoke 20 termination resistor 31 center conductor 32 ferrite 33, 34, 35 printed circuit board 36a, 36b, 36c matching capacitance 37 termination Resistor 38 Case 39a, 39b Permanent magnet 40a, 40b Magnetic yoke 41 Strip conductor 42 Through hole 43 Input / output terminal 44 Earth terminal

Claims (3)

[Claims] 1. A center conductor having a plurality of input / output terminals,
A non-contact having a ferrite laminated on the central conductor, a plurality of matching capacitors respectively connected to the plurality of input / output terminals, a permanent magnet for applying a magnetic field to the ferrite, and a magnetic yoke for forming a closed magnetic circuit. In the reversible circuit element, the center conductor is a single strip conductor having a plurality of conductor portions radially extending at equal angular intervals, and the matching capacitance is a dielectric material larger than the ferrite. Non-reciprocal circuit element. 2. The magnetic yoke is used as a ground by mounting the ferrite and a matching capacitance arranged around the ferrite, and the permanent magnet applies a magnetic field stronger than its resonance magnetic field to the ferrite. The nonreciprocal circuit device according to claim 1, characterized in that. 3. A disk-shaped ferrite is used as the ferrite, and a disk-shaped permanent magnet is used as the permanent magnet.
The nonreciprocal circuit device according to claim 1 or 2, wherein the nonreciprocal circuit device is provided.