JP2002344207A - Non-reciprocal circuit element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a wide-band non-reciprocal circuit element that is small- sized and can be assembled easily. SOLUTION: This non-reciprocal circuit element is provided, having a plurality of center conductors which are laminated upon another, in a state with the conductors cross each other in insulated states through a magnetic material upon which a DC magnetic field is impressed and a matching capacitor connected to one end sections of the conductors. In this circuit element, each of the center conductors connected to input-, output-, and dummy port-side terminals is formed in a plurality of layers and the conductors are electrically connected in series.

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 a circulator and an isolator used for a communication device such as a mobile phone and a mobile phone.

[0002]

2. Description of the Related Art Generally, a nonreciprocal circuit device has a function of causing little attenuation in a signal transmission direction and increasing attenuation in a reverse direction.
It is used in a transmitting / receiving circuit of a mobile communication device such as a mobile phone and a car phone used in the HF band. With the miniaturization of these communication devices, there is an increasing demand for miniaturization and low profile of non-reciprocal circuit devices.

As an example of such a non-reciprocal circuit device, a non-reciprocal circuit device using an assembly having a structure in which a center conductor made of a metal plate is wound around a magnetic material is used. FIG. 10 is a perspective view of a magnetic material used in a conventional non-reciprocal circuit device. 10d shown in the figure is a magnetic material. The center conductor 10 extends from the bottom surface (not shown) of the magnetic body 10d to the top surface via the side surface.
a, 10b, and 10c are arranged so as to be wound. The three center conductors are approximately 120
They are arranged in a state of being electrically insulated from each other via an insulating sheet so as to form an angle of degrees. One end of each center conductor is connected to the ground plate at the bottom of this assembly, matching capacitors 10e, 10f, and 10g are connected in parallel to the other end, and the dummy port terminals are terminated in parallel with the matching capacitors. The magnetic portion of the non-reciprocal circuit device (isolator) is configured by connecting the resistor 10h and absorbing a signal entering in the reverse direction.

As a means for reducing the size of a nonreciprocal circuit device, for example, there is an isolator described in Japanese Patent Application Laid-Open No. Hei 8-23212. This isolator is a laminated isolator having a structure in which a center conductor is embedded in a magnetic material. FIG.
FIG. 1 shows a perspective view of this conventional magnetic body. The outer shape of the magnetic body is a rectangular parallelepiped shape, and the center conductor is embedded therein. This magnetic body 11e constitutes a three-port nonreciprocal circuit element, and 3
The two center conductors 11a, 11b, 11c are embedded so as to intersect with each other at an angle of 120 degrees, and the widths of these center conductors are substantially equal. At one end of each of the center conductors 11a, 11b and 11c, a capacitor electrode portion 11d for obtaining a matching capacitance is formed integrally with the center conductor. The magnetic body 11e is formed, for example, by a method of laminating a plurality of magnetic green sheets including three magnetic green sheets having a center conductor or the like formed on the surface thereof by printing or the like, and pressing and firing the green sheets integrally. Individual magnetic materials are obtained by methods such as punching and cutting.

[0005]

With the downsizing of mobile communication devices such as mobile phones, high-frequency components including non-reciprocal circuit devices are required to be further reduced in size. In a non-reciprocal circuit device, a magnetic material which is a main component of the non-reciprocal circuit device requires a larger space than other components. Therefore, in order to reduce the size of the non-reciprocal circuit device, it is necessary to reduce the size of the magnetic material. .
However, when the size of the magnetic material is reduced, the inductance of the center conductor is reduced, so that the bandwidth during operation is sharply reduced, and the characteristics are deteriorated.

FIG. 12 shows an arrangement of a center conductor in a conventional nonreciprocal circuit device. In the figure, (A) shows the structure of the center conductor shown in FIG. 10, and (B) simplifies the structure of the center conductor shown in FIG. In any case, the center conductor of the conventional structure has a coil-like structure arranged so as to be wound by 磁性 of the circumference from the top to the side of the magnetic body. Generally, the inductance of the coil (hereinafter referred to as L) is given by the following (Equation 1). L = μ · n ² · S · I (Formula 1) (μ: magnetic permeability n: number of turns S: cross-sectional area of coil
I: Current) In general, the relationship between the bandwidth (half width) and L of the RLC parallel resonance circuit is given by the following (Equation 2). f ₂ −f ₁ = L · (2π · _fr ² / R) (Equation 2) (f ₂ −f ₁ : half-value width _fr : resonance frequency R: resistance value) FIG. 12 shows that the size of the magnetic material decreases. As is clear, the center conductor wound around the surface of the magnetic material becomes shorter,
S made by the center conductor is small, and L is lower than (Equation 1). As a result, the bandwidth is reduced according to (Equation 2).

From Equations (1) and (2), it can be seen that L needs to be increased in order to obtain a sufficient bandwidth even if the magnetic material is downsized. Here, as means for increasing L, there is, for example, one disclosed in Japanese Patent Application Laid-Open No. Hei 5-37206. This means has a structure in which L is increased by increasing the number of turns n of the center conductor wound around the magnetic body. That is, the structure shown in FIG. 13 in which the center conductor is wound by about 3/4 circumference so as to contact the upper surface of the magnetic material from the upper surface to the lower surface via the side surface, and about 3/3 so as to contact the upper surface, the side surface and the lower surface of the magnetic material. The structure shown in FIG. 14 is wound around two turns. In these structures, FIG.
Since the number of turns n is larger than that of the conventional structure shown in (1), L is increased by (Equation 1). As a result, even when the size of the magnetic body is small, the bandwidth can be made wider than that of (Equation 2).

However, in order to arrange the center conductor as shown in FIG. 13 and FIG. 14, it is necessary to control the angle and position of the center conductor around the surface of the bulk magnetic material with high precision and to increase the number of steps. Not only is it technically difficult but also difficult.

In order to obtain a function as a non-reciprocal circuit, one end of each of the center conductors on the input side, the output side, and the dummy port side is connected to each terminal, and the other end is connected to each terminal. Must be connected to ground. FIG. 13 and FIG.
In the structure shown in FIG. 4, there are three places to be connected to the ground, one for each central conductor, a total of three places. Since the structure is complicated, the man-hour for assembling also increases accordingly.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems. A non-reciprocal circuit device which is small in size, has a wide band, and is easy to assemble, has a sufficient L even if the magnetic material is reduced in size. It is to provide.

[0011]

In order to achieve the above object, a first aspect of the present invention is to provide a semiconductor device having a plurality of central conductors laminated and arranged so as to intersect with each other in an insulated state via a magnetic body to which a DC magnetic field is applied. In a non-reciprocal circuit device including a matching capacitor connected to one end of each center conductor, each of the center conductors connected to each terminal on the input side, the output side, and the dummy port side has a plurality of layers, and each A non-reciprocal circuit device characterized in that central conductors each composed of a plurality of layers connected to terminals are electrically connected in series.

The present invention is a structure of a magnetic body in which each of the center conductors on the input side, the output side, and the dummy port side is formed in a plurality of layers, and they are electrically connected in series. FIG.
FIG. 1 shows a schematic diagram of this structure. (A) is an outline of a laminated structure,
(B) is an outline of the structure focusing on the center conductors 1a and 1b. Reference numerals 1a and 1b denote center conductors formed of strip conductors. One end of the center conductor 1a is connected to a terminal (not shown), and the other end is electrically connected to one end of the center conductor 1b via the conductor 1c. One end on the opposite side of the center conductor 1b is connected to a ground electrode 1d via a conductor 1e. By connecting the center conductors in series in this manner, the length of the center conductor is increased, and the number of turns n can be increased. Therefore, it is possible to widen the bandwidth. Further, since the magnetic material according to the present invention is formed by printing and forming a strip conductor on the sheet surface of the magnetic material and laminating and arranging the strip conductor, the position of the central conductor and the position of the central conductor compared to the conventional method of winding the central conductor around the bulk magnetic material are improved. The control of the angle is easy and the assembly is simple. Further, since the periphery of the center conductor is filled with a magnetic material, the high-frequency magnetic field generated in the input-side center conductor is concentrated near the center conductor, and the signal is efficiently transmitted to the output-side center conductor.

Next, a second aspect of the present invention is to connect a plurality of center conductors stacked and arranged so as to intersect with each other in a state of insulation via a magnetic body to which a DC magnetic field is applied, and to one end of each center conductor. In a non-reciprocal circuit device having a matching capacitor, at least one of the center conductors connected to the input side, the output side, and each terminal on the dummy port side is composed of three or more layers. A part of the central conductors composed of the above layers is electrically connected in parallel, and the parallel-connected layer and the central conductors of the other layers are electrically connected in series. It is a non-reciprocal circuit device.

According to the present invention, at least one of the center conductors on the input side, the output side, and the dummy port side has three conductors.
A plurality of layers are formed, a part of the three or more layers is electrically connected in parallel, and the layers connected in parallel and the remaining layers are electrically connected in series. FIG. 2 schematically shows this structure. (A) is an outline of a laminated structure of a magnetic body, and (B) is an outline of a structure focusing on the center conductors 1a, 1b, 2a, and 2b. 1a, 1b, 2a and 2b are central conductors formed of microstrip conductors. One end of each of 1a and 2a is connected to a terminal via a conductor 2f, and the other end is connected to a conductor 1c. Thus, 1a and 2a are electrically connected in parallel via conductors 2f and 1c. On the other hand, 1b and 2b are similarly electrically connected in parallel via 1c and 2e, one end of which is connected to the ground electrode 1d via the conductor 2e, and the other end is connected to the conductor 1c. Therefore, the upper structure 2c composed of 1a and 2a and the lower structure 2d composed of 1b and 2b are electrically connected in series via the conductor 1c. Even with such a structure, a wide bandwidth can be easily obtained as in the case of the first aspect. Also, 2c, 2d
, The input side, the output side, and the dummy port side each include one or more central conductors, and by alternately arranging them, it is possible to strengthen the coupling between the central conductors and obtain a low insertion loss. . For example, as shown in each of 2c and 2d in FIG. 2B, when the input-side center conductor is arranged above and below the output-side center conductor one layer, the high-frequency magnetic field generated by the input-side center conductor is as shown in FIG. ) Are distributed as indicated by arrows. As a result, the high-frequency magnetic field generated by the input-side central conductor can surround the output-side central conductor without waste, and a large induced electromotive force is generated in the output-side central conductor. As a result, a low insertion loss can be realized.

According to the first or second aspect of the present invention, an isolator can be provided by connecting a matching capacitor as a terminating resistor to the terminal on the dummy port side.

In the first to third aspects of the present invention, it is preferable that the electrode pattern of the matching capacitor is formed on the uppermost surface of the magnetic material, and the terminating resistor of the dummy port portion is formed on the outer surface of the magnetic material. . This makes it possible to reduce the number of components when assembling the non-reciprocal circuit element, and to adjust the capacitance and resistance of the capacitor by trimming, which is desirable in mass production.

[0017]

Embodiments of the present invention will be described below with reference to the drawings. A first embodiment of the present invention will be described with reference to FIG. This non-reciprocal circuit device has a structure in which 12 layers of magnetic sheets (a) to (l) are laminated, and a back surface (m) of the lowermost layer (l) is provided with a ground electrode 3a, an input, an output, and
The connection terminals 3b, 3c, 3d on the dummy port side are individually formed. 3e formed in the (f) layer and 3f formed in the (h) layer are input-side center conductors, and 3e and 3f are conductors 3
g are electrically connected in series. Reference numeral 3f is electrically connected to a ground electrode 3i formed in the layer (l) via a conductor 3h. The ground electrode 3i is electrically connected to the lowermost ground electrode 3a via a side electrode (not shown). The input side center conductor is formed with the above structure. By the same means, the output side center conductor is 3j, 3
k, 3i, the center conductor on the dummy port side is 3l, 3m, 3m
It is formed by electrically connecting i in series. FIG.
Although through-holes are used as conductors such as 3g and 3h for connecting the center conductor therein, the present invention is not limited to this, and connection may be made by forming external electrodes on the side surfaces of the magnetic material, for example. In FIG. 3, the order of lamination of the respective center conductors is 3l, 3j, 3e, 3f, 3k, and 3m from the top, but the present invention is not limited to this order. In short, the central conductors on the input side, output side and dummy port side are electrically insulated from each other via a magnetic material.
It suffices if they are stacked and arranged so as to cross each other at an angle of about 120 degrees. One end of each of 3e, 3j, and 31 is exposed on the side surface of the magnetic body, and is connected to a connection terminal described below via an external electrode (not shown).

On the upper side of the magnetic material, the matching capacitor patterns on the input side, output side and dummy port side are arranged on the uppermost surface of the layer (a) through the layer (b) on which the dummy layer (c) and the ground electrode 3q are formed. 3n, 3o, and 3p are formed, and are respectively connected to the lowermost connection terminals 3b, 3c, and 3d via side electrodes.
Electrically connected to These capacitor patterns 3n,
An earth electrode 3q is arranged below the layers 3o and 3p, and is electrically connected to the lowermost earth electrode 3a via side electrodes. By arranging the matching capacitor electrode pattern on the top surface of the magnetic body in this way, the trimming of the capacitor pattern becomes possible, and the adjustment of the matching capacitance becomes easy. A laser or a luter may be used for trimming. CO ₂ laser (wavelength
1.06 μm) and a YAG laser (wavelength 10.6 μm) are suitable, but a YAG laser is more preferable since a YAG laser has a lower reflectivity to a silver conductive pattern and has better workability. Each of these magnetic layers is laminated and pressed, and then sintered to form a laminated magnetic substance.

FIG. 4 shows the components of the non-reciprocal circuit device and how to assemble them. The magnetic body 4a formed as described above is disposed on the electrode substrate 4b. The ground surface 4c, input terminal 4d, output terminal 4e, and dummy port terminal 4f of the electrode substrate are respectively connected to corresponding connection terminals (corresponding to 3a, 3b, 3c, 3d in FIG. 3) provided on the lower surface of the magnetic body 4a. Electrically connected. A permanent magnet 4h for applying a DC magnetic field is arranged above the above structure, and these are surrounded by metal cases 4i and 4j which also serve as magnetic yokes, thereby having a function as a non-reciprocal circuit element. Also, by connecting the chip-type resistor 4g so as to connect the dummy port terminal 4f on the electrode substrate 4b and the ground plane 4c, it is possible to have a function as an isolator.

Next, FIG. 5 shows a result of performing a high-frequency structure simulation according to the present embodiment. In FIG. 5, a triangle indicates the result of the present embodiment, and a triangle indicates the result of the conventional example shown in FIG. From this result, the center frequency is 1.95 GH
At z, the curve of the insertion loss due to the present structure shows a more gently convex shape than the conventional structure, and it can be seen that the band is widened. This is considered to be due to the fact that the bandwidth was widened from the result (Equation 2) of increasing the center conductor L inside the magnetic body as described above. Although the insertion loss of the present embodiment is deteriorated in the result of FIG. 5, this is due to the impedance mismatch between the input side and the output side. For example, the width of the center conductor is adjusted. It is considered that the impedance can be improved by matching the impedance.

A second embodiment of the present invention will be described with reference to FIG. This embodiment has a structure in which 12 layers of magnetic sheets are laminated similarly to the first embodiment, and has two layers of central conductors on the input side, the output side and the dummy port side. For example, 6a, 6c, and 6e constitute an input-side center conductor, and 6a and 6c are formed through a through-hole conductor 6b.
Are electrically connected in series, and 6c and 6e are electrically connected in series via the through-hole conductor 6d. 6a
One end is exposed on the side of the magnetic material, and an external electrode (not shown)
To the connection terminal 3b on the lowermost surface. On the other hand, one end of 6e is exposed on the side surface of the magnetic material, and is connected to the lowermost ground electrode 3a via an external electrode (not shown). The input side center conductor is formed by the above-described means. The output side center conductor and the dummy port side center conductor are formed by the same means. Even if such a means is used, the center conductor L can be increased as in the first embodiment, and the bandwidth can be widened. The structure of the other parts is the same as that of the first embodiment, and the description is omitted.

A third embodiment of the present invention will be described with reference to FIG. In the magnetic body of this example, the input side center conductors are 7a and 7
b, 7c, 7d, the output-side central conductor is composed of two layers, 7e and 7f, and the dummy-port-side central conductor is composed of two layers, 7g and 7h. 7a and 7b are electrically connected in parallel by a side electrode (not shown) made of a magnetic material and a through-hole conductor 7i. 7c and 7d are electrically connected in parallel by similar means. And 7a, 7b and 7c, 7d
Are electrically connected in series by a through-hole conductor 7i. With such a forming means, it is possible to increase L of the central conductor. By alternately laminating the input-side center conductors and the output-side center conductors in the portion 2c, the coupling between the input-side center conductors 7a and 7b and the output-side center conductor 7e can be strengthened. Similarly, in the 2d portion, the coupling between the input-side center conductors 7c and 7d and the output-side center conductor 7f can be strengthened. In the structure shown in FIG. 7, the input-side central conductor is composed of four layers, and the output-side and dummy port-side central conductors are each composed of two layers. However, the present invention is not limited to this number of layers. , At least one of the center conductors on the output side and the dummy port side may have three or more layers. The structure of the other parts is the same as that of the first embodiment, and the description is omitted.

In the first, second, and third embodiments, an external resistor is used as the terminating resistor. However, as shown in FIG. The function as a non-reciprocal circuit element can also be provided by forming a printing resistor. According to this example, when the electrode pattern of the magnetic material is formed, the resistor portion can be formed by printing at the same time, so that the number of assembling steps can be reduced.
FIG. 9 shows an assembly state using the magnetic body of FIG. The magnetic material 9a is connected to the electrode substrate 9b, a permanent magnet 9h is arranged on the upper part of the structure, and is surrounded by upper and lower cases 9i and 9j which also serve as a magnetic yoke, thereby having a function as a non-reciprocal circuit element. As a result, the number of parts and man-hours can be reduced, and the size, weight, and cost of the nonreciprocal circuit device can be reduced. Also, by trimming the printed resistance, even if the impedance on the dummy port side is not accurately set to 50Ω at the time of design, for example, it is possible to fine-tune the impedance matching by adjusting the terminating resistance to an arbitrary resistance value. Isolation can be easily obtained.

[0024]

According to the present invention, the input side, output side and dummy port side center conductors formed over a plurality of layers are electrically connected in series, or at least one of the center conductors is connected. One is formed over three or more layers, some of the center conductors are electrically connected in parallel, and this is electrically connected in series with the center conductor of another layer, so that the inductance L of the center conductor is large. It is possible to easily obtain the structure, and as a result, it is possible to prevent the bandwidth from being reduced due to the downsizing of the magnetic body. Further, by forming the printing pattern of the matching capacitor and the terminating resistor on the surface of the magnetic material, it is possible to adjust the characteristics using trimming, and to reduce the size and weight of the nonreciprocal circuit device.

[Brief description of the drawings]

FIG. 1 is a schematic diagram illustrating a first invention of the present invention,
(A) is a perspective view of the outline of the magnetic body, and (B) is a side sectional view thereof.

FIG. 2 is a schematic diagram illustrating a second invention of the present invention,
(A) is a perspective view of the outline of the magnetic body, and (B) is a side sectional view thereof.

FIG. 3 is a development view of a green sheet constituting a magnetic body according to the first embodiment of the present invention.

FIG. 4 is a perspective view showing the assembly of the isolator according to the first embodiment of the present invention.

FIG. 5 is a characteristic diagram showing insertion loss characteristics of an example of the present invention and a conventional example.

FIG. 6 is a development view of a green sheet constituting a magnetic body according to a second embodiment of the present invention.

FIG. 7 is a development view of a green sheet constituting a magnetic body according to a third embodiment of the present invention.

FIG. 8 is a diagram illustrating an example of a print resistor provided on a magnetic body according to another embodiment of the present invention.

FIG. 9 is a perspective view showing an assembly of an isolator according to another embodiment of the present invention.

FIG. 10 is a schematic view showing a magnetic body assembly structure of a conventional isolator.

FIG. 11 is a diagram schematically showing a relationship between a magnetic body and a center conductor in the related art.

FIG. 12 is a side view showing a relationship between a magnetic body and a center conductor in a conventional technique.

FIG. 13 is a side view showing a relationship between a magnetic body and a center conductor in another conventional technique.

FIG. 14 is a side view showing the relationship between a magnetic body and a center conductor in another conventional technique.

[Explanation of symbols]

 1a, 1b, 2a, 2b ... center conductor, 1d, 3a, 3i, 3q ... ground electrode, 1c, 1e, 2e ... through hole electrode, 3b, 3c, 3d ... connection terminal electrode, 3e, 3f ... input side center conductor .., 3j, 3k... Output-side center conductor, 31, 3m... Dummy-side center conductor, 3n, 3o, 3p... Capacitor electrode, 4a, 9a... Magnetic material, 4b, 9b... Electrode substrate, 4c. Input terminal, 4e: Output terminal, 4f: Dummy port terminal, 4g: Chip resistor element, 4h, 9h: Permanent magnet, 4i, 4j, 9i, 9j: Metal case, 6a, 6e, 6c: Input side center conductor, 6b 6d: through-hole conductor; 7a, 7b, 7c, 7d: input-side center conductor; 7e, 7f: output-side center conductor; 7g, 7h: dummy-port-side center conductor; 7i: through-hole conductor

Claims (4)

[Claims] 1. A non-reciprocal device comprising: a plurality of center conductors laminated so as to intersect with each other in an insulating state via a magnetic body to which a DC magnetic field is applied; and a matching capacitor connected to one end of each center conductor. In the circuit element, the center conductor connected to each terminal on the input side, the output side, and the dummy port side is formed in a plurality of layers, respectively, and the center conductor formed in each of the plurality of layers connected to each of the terminals is electrically connected. A non-reciprocal circuit device which is connected in series. 2. A non-reciprocal device comprising: a plurality of central conductors stacked so as to intersect with each other in an insulating state via a magnetic body to which a DC magnetic field is applied; and a matching capacitor connected to one end of each central conductor. In the circuit element, at least one of the center conductors connected to the input side, the output side, and each terminal on the dummy port side is formed of three or more layers, and of the center conductors formed of the three or more layers. A non-reciprocal circuit device, wherein a part of the layers is electrically connected in parallel, and the layer connected in parallel and a center conductor of another layer are electrically connected in series. 3. The non-reciprocal circuit device according to claim 3, wherein a terminating resistor connected to the center conductor on the dummy port side is printed on the outer surface of the magnetic body. 4. The non-reciprocal circuit device according to claim 1, wherein an electrode pattern of a matching capacitor connected to each port is arranged on an uppermost surface of the magnetic body.