JP2003347806A - Non-reciprocal circuit element - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a non-reciprocal circuit element which is superior in signal transmission efficiency by restricting the insertion loss. <P>SOLUTION: In the non-reciprocal circuit element 1, a common electrode 14 is provided to a plate-like magnetic body 15, three center conductors 11,12 and 13 extended in three directions from the common electrode 14 are bent so as to wrap the magnetic body 15, the center conductors 11 to 13 are crossed at a predetermined angle, capacitors C<SB>1</SB>to C<SB>3</SB>are connected to one ends of the center conductors 11 to 13, the capacitance of the capacitor C<SB>1</SB>connected to one center conductor 11 crossed at a side, away from the magnetic body 15 is set larger than the capacitance of the capacitor C<SB>2</SB>connected to the other center conductor 12. <P>COPYRIGHT: (C)2004,JPO

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a non-reciprocal circuit device used in a high frequency band such as a microwave, that is, an isolator, a circulator, and the like.

[0002]

2. Description of the Related Art A lumped constant type isolator is a high-frequency component having a function of passing a signal in a transmission direction without loss and preventing a signal from passing in a reverse direction. Used in the circuit section. As an example of such an isolator, there is one having a configuration shown in FIG.

The conventional isolator shown in FIG. 10 mainly includes a magnetic assembly 50 and a permanent magnet 56. The magnetic assembly 50 includes a magnetic body 55 made of a flat disc-shaped ferrite, a common electrode 54 made of a metal plate provided along the lower surface thereof, and a three-way extending radially from the common electrode 54. The first center conductor 51, the second center conductor 52, and the third center conductor 53 are wound around the surface of the magnetic body 55.

The first, second and third center conductors 51 to 5
3 are bent along the magnetic body 55 and are overlapped on the surface side of the magnetic body 55 at an intersection angle of about 120 °. Although not shown in the drawing, the center conductors 51, 52, and 53 are individually insulated from each other on the surface side of the magnetic body 55 by an insulating sheet. Referring to the positional relationship between the respective center conductors 51 to 53, as shown in FIG.
5 and then the first central conductor 51
The second central conductor 52 is superimposed on the upper side of the first central conductor 52, and the third central conductor 53 is further superimposed on the second central conductor 52.

The distal ends of the central conductors 51, 52, 53 are disposed so as to protrude to the side of the magnetic body 55 to form port portions P1, P2, P3. Capacitors C1, C2, and C3 for matching are respectively connected to the port portions P1 to P3, and a terminating resistor R is connected to the port portion P3 via the capacitor C3, and these form a magnetic circuit together with the permanent magnet 56. The isolator is configured by being housed in the magnetic yoke to be configured and applying a DC magnetic field to the magnetic assembly 50 by the permanent magnet 56. In this isolator, port P1 is an input terminal, and port P2 is an output terminal.

Each of the center conductors 51 to 53 is continuously connected and integrated at a common electrode 54 serving as a ground portion, and is formed to project from the common electrode 54 in three directions.
53 are configured to be accurately assembled to the magnetic body 55 at a predetermined angle. Each center conductor 51-5
3 is wound around the surface of the magnetic body 55,
The high dielectric material 55 is opposed to the common electrode with the magnetic material 55 interposed therebetween, thereby forming a microstrip line. Therefore, in the conventional isolator, the characteristic impedance of at least a pair of center conductors (first and second center conductors 51 and 52) constituting the input / output terminals among the three center conductors is matched to reduce the insertion loss. Is preferred.

[0007]

However, in the conventional isolator, as is clear from the above-described positional relationship between the center conductors, the second center conductor 52 and the magnetic field are intersected at the intersections of the center conductors 51 to 53. Since the first central conductor 51 is located between the first central conductor 51 and the body 55, the second central conductor 52 is disposed farther away from the magnetic body 55 than the first central conductor 51. There is a problem in that a difference occurs in the distance, and the characteristic impedance of the first and second center conductors 51 and 52 does not match due to the difference in distance, thereby increasing insertion loss and reducing signal transmission efficiency.

The present invention has been made in view of the above circumstances, and has as its object to provide a non-reciprocal circuit device which suppresses insertion loss and has excellent signal transmission efficiency.

[0009]

In order to achieve the above object, the present invention employs the following constitution. In the non-reciprocal circuit device of the present invention, a common electrode is disposed on one surface side of the plate-shaped magnetic body, and the common electrode extends from the outer periphery of the common electrode in three directions.
The two center conductors are bent to the other side of the plate-shaped magnetic body so as to enclose the plate-shaped magnetic body, and the respective center conductors cross each other at a predetermined angle on the other side, and A capacitor is connected to one end of the conductor.
Regarding any one pair of center conductors of the two center conductors, the conductor width of one of the pair of center conductors that intersects on the side remote from the plate-shaped magnetic body is set to be larger than the conductor width of the other center conductor. It is characterized by being narrow.

According to this nonreciprocal circuit device, the conductor width of one center conductor that intersects on the side distant from the plate-like magnetic body is made larger than the conductor width of the other center conductor that intersects on the side near the plate-like magnetic body. By making the width narrow, the characteristic impedance of the pair of center conductors can be matched (matching), whereby the insertion loss of the nonreciprocal circuit device can be reduced and the signal transmission efficiency can be improved. Note that the center frequency is a frequency at which the reflection coefficient shows a minimum value.

In the nonreciprocal circuit device of the present invention,
When the conductor width of the one center conductor is h1 and the conductor width of the other center conductor is h2, (h2−h1) / h2 ×
It is preferable that the ratio of the difference represented by 100 (%) is in the range of 10% or more and 20% or less. More preferably, the ratio of the difference is in the range of 14% to 17%.

According to the nonreciprocal circuit device, since the ratio of the difference between the conductor widths of the pair of center conductors is within the above range, the characteristic impedances of the pair of center conductors can be matched (matching). The signal transmission efficiency can be improved by reducing the insertion loss of the circuit element.

Next, a nonreciprocal circuit device according to the present invention is characterized in that the pair of central conductors are input / output terminals. According to the above-described non-reciprocal circuit device, a non-reciprocal circuit device having low insertion loss can be configured by using the pair of center conductors as input / output terminals.

[0014]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a perspective view showing a main part of an isolator as an example of a non-reciprocal circuit device according to a first embodiment of the present invention, and FIG. 2 is an exploded perspective view of the isolator. The isolator 1 shown in FIG.
And a permanent magnet 16. The magnetic assembly 10 includes a plate-shaped magnetic body 15 made of a flat disk-shaped ferrite, a common electrode 14 made of a metal plate provided along the lower surface (one surface) 15b, and a radial pattern from the common electrode 14. First central conductor 1 extending in three directions and wound around surface (other surface) 15a of plate-shaped magnetic body 15
1, a second center conductor 12 and a third center conductor 13.

Each of the first, second and third center conductors 11 to 13 is bent along the plate-like magnetic body 15 so that the first, second and third center conductors 11 to 13 are substantially 12 mm apart from each other on the surface (other surface) 15 a side of the plate-like magnetic body 15.
They are crossed and overlapped at a crossing angle of 0 °. Although omitted in the drawing, the center conductors 11 to 13 are individually insulated from each other on the surface 15a side of the plate-shaped magnetic body 15 by an insulating sheet. Referring to the positional relationship at the intersection of the center conductors 11 to 13, as shown in FIG. 1, the second center conductor 11 is arranged closest to the plate-shaped magnetic body 15, and then the second center conductor 11 12, a first central conductor 11 is superimposed on the first central conductor 11,
The third central conductor 13 is superimposed on the third central conductor 13. That is, the first center conductor 11 is
The third center conductor 13 is disposed farther away from the plate-shaped magnetic body 35 than the first center conductor 11 and the second center conductor 12. The third center conductor 13 may be arranged closest to the plate-shaped magnetic body 15 or may be arranged between the first center conductor 11 and the second center conductor 12.

Further, as shown in FIG.
The distal end side of 13 is disposed so as to protrude to the side of the plate-shaped magnetic body 15, and is formed as each of port portions P1, P2, and P3.
A matching capacitor C is connected to each of the ports P1 to P3.
1, C2 and C3 are connected to each other, and a terminating resistor (resistor element) R is connected to the port portion P3 via a capacitor C3, and these are housed together with the permanent magnet 16 in a magnetic yoke constituting a magnetic circuit. An isolator is configured by applying a DC magnetic field to the magnetic assembly 10 with the permanent magnet 16. In this isolator, port P1 is on the input side, and port P2 is on the output side.

As shown in FIG. 2, each of the center conductors 11 to 13 is continuously provided and integrated at a common electrode 14 serving as a ground portion, and is formed to project from the common electrode 14 in three directions. Then, as shown in FIG. 1, the central conductors 11 to 13 are configured to be accurately assembled to the plate-shaped magnetic body 15 at a predetermined angle. Each center conductor 11-13
Is wound around the surface 15a of the plate-shaped magnetic body 15 so as to face the common electrode 14 with the highly dielectric plate-shaped magnetic body 15 interposed therebetween, thereby forming a microstrip line.

As shown in FIGS. 1 and 2, the first, second and third central conductors 11 to 13 have slits 11a,
12a and 13a are provided respectively. By forming the slits 11a, 12a, and 13a, the center conductors 11 to 13 are each divided into two divided conductors. That is, the first central conductor 11 is divided into divided conductors 11b1 and 11b2, the second central conductor 12 is divided into divided conductors 12b1 and 12b2, and the third central conductor 13 is divided into divided conductors 13b1 and 13b2. I have. As shown in FIG. 2, when the conductor width of the first center conductor 11 is h1 and the conductor width of the second center conductor 12 is h2, h1> h2 in the present embodiment. . That is,
The conductor width h1 of the first center conductor (one center conductor) 11 intersecting on the side distant from the plate-shaped magnetic body 15 is smaller than the conductor width h2 of the second center conductor (the other center conductor). . Here, the conductor width h1 is the sum of the widths hb1 and hb1 of the divided conductors 11b1 and 11b2 and the width ha1 of the slit portion 11a, and the conductor width h2 is the divided conductors 12b1 and 12b2.
Is the sum of the widths hb2, hb2 of the above and the width ha2 of the slit portion 12a. The slit widths ha1, hb1 may be the same or different, and the divided conductor widths hb1, hb2 may be the same or different.

As described above, the conductor width h1 of the first center conductor 11 (the center conductor located on the upper side) is changed to the second center conductor 1
By making the conductor width h2 smaller than the conductor width h2 of the center conductor 2 (lower center conductor), the characteristic impedance of each of the center conductors 11 and 12 can be matched. That is, on the front side 15a of the plate-shaped magnetic body 15, the first center conductor 1
1 is farther from the common electrode 14 than the second center conductor 12, the characteristic impedance is different when the conductor widths h1 and h2 are the same, but the conductor width h1 is different from the conductor width h2. By making the width narrow, the characteristic impedance of the first central conductor 11 can be matched with the characteristic impedance of the second central conductor 12. Thereby, the insertion loss of the isolator can be reduced, and the signal transmission efficiency can be improved.

The optimum relationship between the conductor widths h1, h2 of the first and second center conductors 11, 12 is given by (h2-h1) / h2
The ratio of the difference represented by × 100 (%) is 10% or more and 20%
It is preferably in the following range, more preferably in the range of 14% to 17%. If the ratio of the difference between the conductor widths h1 and h2 is less than 10%, the characteristic impedances of the respective center conductors will not match, which is not preferable. If the difference ratio exceeds 20%, the characteristic impedances of the respective center conductors may be matched. It is not preferable because it becomes more difficult. Note that the conductor width of the third center conductor 13 is the first and second conductors.
Conductor width h1, h2 of one of the center conductors 11, 12
And the conductor width may be different from the conductor widths h1 and h2.

As for the capacities Cap1 and Cap2 of the capacitors C1 and C2 connected to the first and second center conductors 11 and 12, the capacity Cap1 may be larger than the capacity Cap2. Are preferably the same in terms of characteristics. Further, the capacitance Cap3 of the capacitor C3 connected to the third center conductor 13 may be the same as one of the capacitances Cap1 and Cap2, or may be different from the capacitances Cap1 and Cap2. Capacitance Cap1 of capacitor C1
By making it larger than 2, it becomes possible to make the center frequency of the reflection coefficient of the first center conductor 11 coincide with the center frequency of the reflection coefficient of the second center conductor 12.
Thereby, the insertion loss can be reduced and the signal transmission efficiency can be improved.

The relationship between the capacitance Cap1 of the capacitor C1 connected to the first center conductor 11 and the capacitance Cap2 of the capacitor connected to the second center conductor 12 is as follows, for example.
The capacity difference represented by the formula of (Cap1−Cap2) / Cap1 × 100 (%) is preferably in the range of 10% or more and 20% or less, more preferably in the range of 14% or more and 17% or less.

The overall structure of the isolator 1 of this embodiment will be described. As shown in FIG.
Closed magnetic circuit (magnetic yoke) composed of the lower yoke 22
In other words, between the upper yoke 21 and the lower yoke 22, the square plate-shaped permanent magnet 16, the spacer member 17, the magnetic assembly 10, the capacitor plates 24, 25, 26, and the terminating resistor 27 (R) And a resin case 23 for accommodating them. The magnetic assembly 10 has first, second,
The third center conductors 11 to 13 are wound around the plate-shaped magnetic body 15. Then, the capacitor plate 24 is attached to the first center conductor 11 and the second center conductor 12
The capacitor plate 25 is attached to the third central conductor 1
3, a capacitor plate 26 and a terminating resistor 27 are attached. The capacitor C1 shown in FIG. 1 is built in the capacitor plate 24, the capacitor C2 is built in the capacitor plate 25, the capacitor C3 is built in the capacitor plate 26, and the terminal resistor 27 is mounted on the terminating resistor 27. R is built in.

According to the isolator 1 of the present embodiment, the first center conductor 1 that intersects on the side remote from the plate-shaped magnetic body 15
Since the first conductor width h1 is smaller than the conductor width h2 of the second center conductor 12 that intersects on the side closer to the plate-shaped magnetic body 15, the characteristic impedance of each of the center conductors 11 and 12 can be matched. As a result, the insertion loss of the isolator 1 can be reduced and the signal transmission efficiency can be improved.

FIG. 4 is a circuit diagram showing an example of a circuit configuration of a portable telephone device in which the isolator 1 of the present embodiment is incorporated. In this circuit configuration, the antenna 140 has a duplexer (a common antenna). 141)
The IF circuit 144 is connected to the output side of the duplexer 141 via a low noise amplifier (amplifier) 142, an interstage filter 148, and a mixing circuit 143, and the isolator 1 of the present embodiment is connected to the input side of the duplexer 141.
, A power amplifier (amplifier) 145, and an IF circuit 147 via a mixing circuit 146.
6 is connected to a local oscillator 150 via a distribution transformer 149. The duplexer 141 includes two ladder-type SAW filter devices 138, for example. And the ladder type SAW filter device 1
38, 138 are connected to antenna 140, respectively.
Side, and one ladder-type SAW filter device 13
8 is a low-noise amplifier (amplifier) 142
And the other ladder type SAW filter device 138
Are connected to the isolator 1. The isolator 1 having the above configuration is used by being incorporated in a circuit of a portable telephone device as shown in FIG. 4, and a signal from the isolator 1 to the duplexer 141 side is passed with a low loss, but a signal in the opposite direction has a loss. It acts to cut off and increase. This has the effect of preventing unnecessary signals such as noise on the amplifier 145 side from being input back to the amplifier 145 side.

FIG. 5 shows the principle of operation of the isolator 1 having the configuration shown in FIGS. The isolator 1 incorporated in the circuit shown in FIG. 5 transmits a signal from the first port P1 shown by the reference to the second port P2 shown by the reference, but transmits the signal from the second port P2 side of the reference to the third port P2. The signal to the port P3 is attenuated and absorbed by the terminating resistor R, and the signal from the third port P3 indicated by the symbol of the terminating resistor R to the first port P1 indicated by the symbol is cut off. Therefore, the effects described above can be obtained when incorporated in the circuit shown in FIG.

The application range of the nonreciprocal circuit device of the present embodiment is not limited to the above embodiment, but can be applied to the following second embodiment.

FIGS. 6 to 9 show a second embodiment of an isolator among the non-reciprocal circuit devices according to the present invention.
The isolator 31 of this embodiment includes a permanent magnet 34, a plate-like magnetic body 35 made of a ferromagnetic material, and a center conductor 36, 3 in a magnetic closed circuit composed of an upper yoke 32 and a lower yoke 33.
7 and 38, a common electrode 40 connecting these central conductors 36, 37 and 38, capacitor substrates 41 and 42 disposed around the plate-shaped magnetic body 35, and a terminating resistor 43.

The upper yoke 32 and the lower yoke 33 are made of a ferromagnetic material such as soft iron and are formed in a rectangular box shape.
Preferably, a conductive layer such as Ag plating is coated on the front and back surfaces of the yokes. A box-shaped magnetic closed circuit is formed by fitting these yokes 32 and 33 together.

In a space surrounded by the lower yoke 32 and the upper yoke 33, in other words, in a closed magnetic circuit formed by the lower yoke 32 and the upper yoke 33, a plate-shaped magnetic body 35 and three center conductors 3 are provided.
A magnetic assembly 45 comprising 6, 37, 38 and a common electrode 40 connecting these central conductors 36, 37, 38 is housed. The plate-shaped magnetic body 35 is made of a ferromagnetic material such as YIG ferrite and has a substantially rectangular plate shape that is horizontally long in a plan view as shown in FIG. More specifically, two opposed long sides 35a, 35a facing each other and these long sides 35a, 3a
5a, short sides 35b, 35b, and long sides 35a,
It is located at both end sides of 35a and 15
It is inclined at an angle of 0 ° (3 for the extension of the long side 35a).
It is inclined at an inclination angle of 0 °), and has a substantially rectangular shape that is horizontally long in a plan view and includes four inclined sides 35d individually connected to the short side 35b. Accordingly, at four corners of the plate-shaped magnetic body 35 in a plan view, inclined surfaces (receiving surfaces) 35d each having a 150 ° inclination with respect to the long side 35a (130 ° inclination with respect to the short side 35b) are formed.

The three center conductors 36 to 38 and the common electrode 40 are integrated as shown in the developed view of FIG.
The electrode portion 46 is mainly composed of the central conductors 36 to 38 and the common electrode 40. The common electrode 40 is composed of a main body 40A made of a metal plate having a substantially similar shape to the plate-like magnetic body 35 viewed from the top. That is, the main body 40A has two long sides 40a, 40a opposed to each other, and short sides 40b, 40b perpendicular to the long sides 40a, 40a.
Are connected to the long sides 40a, 40a at both end sides and inclined at an angle of 150 ° with respect to each of the long sides 40a, and connected to the short side 40b at an inclination angle of 120 °. Do 4
It is a substantially rectangular shape (rectangular shape) in plan view composed of the two inclined portions 40c.

The first center conductor 36 and the second center conductor 37 from the two slopes 40c on one long side of the four corners 40c of the common electrode 40.
Are formed to extend. First, the previous two inclined portions 40c
A first central conductor 36 composed of a first base conductor 36a, a first central conductor 36b, and a first distal conductor 36c extends from one side of the other, while the first central conductor 36 extends from one side of the inclined section 40c. , A second base conductor 37a and a second central conductor 37b
Second central conductor 3 composed of a second tip conductor 37c
7 is extended. The base conductors 36a, 37a
Are inclined portions 40c so as to extend the inclined portions 40c.
The base conductors 36a and 37a are provided with their central axes inclined at an inclination angle of 150 ° with respect to the long side portion 40a of the common electrode 40. Next, each of the central conductors 36b and 37b is parallel to the short side portion 40b of the common electrode 40, in other words, 15 degrees with respect to the central axis (length direction) of the base conductors 36a and 37a.
It is formed with an inclination angle of 0 °, and furthermore, the tip conductors 36c, 3c
7c is 1 to the long side 40a of the common electrode 40.
It is inclined at 50 °. From these facts, the angle θ1 formed between the central axes of the connection conductors 36a and 37a is shown in FIG.
Is set to 60 °, and the tip conductor 36c,
The angle θ2 between the central axes of 36c is 120 ° as shown in FIG.

Next, at the center in the width direction of the first center conductor 36, a slit which passes through the base conductor 36a and the center conductor 36b from the outer periphery of the common electrode 40 and reaches the base end of the tip conductor 36c. A portion 48 is formed.
Is formed, the central conductor 36b is divided into two divided conductors 36b1 and 36b2, and the base conductor 36a is also divided into two.
It is divided into two divided conductors 36a1 and 36a2, and a similar slit portion 49 is formed at the center in the width direction of the second central conductor 37. By forming this slit portion 49, the central conductor 37b is divided into two. The base conductor 37a is divided into the divided conductors 37b1 and 37b2, and the base conductor 37a is also divided into two divided conductors 37a1,
37a2. The end of the slit portion 48 on the side of the common electrode 40 passes through the connection conductor 36a and passes through the common electrode 40.
Of the recess 48 by reaching a position slightly deeper from the outer periphery of the
a, the line length of the first central conductor 36 is slightly increased, and the end of the slit 49 on the side of the common electrode 40 also reaches the outer periphery of the common electrode 40 through the connection conductor 37a. Thus, the concave portion 49a is formed, and the line length of the second central conductor 37 is slightly increased. In addition, the concave portion 48a,
49a is not necessarily required, and need not be provided if the inductance of the center conductors 36 and 37 is sufficiently ensured.

As shown in FIGS. 6 and 9, the width of the first central conductor 36 is defined as h1, and the width of the second central conductor 37 is defined as h1.
In this embodiment, when the conductor width is h2, h1 <h
It is 2. That is, the conductor width h1 of the first central conductor (one central conductor) 36 that intersects on the side away from the plate-shaped magnetic body 35 is smaller than the conductor width h2 of the second central conductor (the other central conductor) 37. Has become. Here, the conductor width h1 is the sum of the widths of the divided conductors 36b1 and 36b2 and the width of the slit portion 48, and the conductor width h2 is the divided conductors 37b1 and 37b.
2 and the width of the slit 49. The widths of the slits 48 and 49 may be the same or different, and the widths of the divided conductors may be the same or different.

The first and second center conductors 36 and 37 are shown in FIG.
As shown in FIG. 7, the common electrode 40 serving as a ground portion is continuously provided and integrated, and is formed so as to protrude from the common electrode 40 in a predetermined direction. As shown in FIGS. 6 and 7, the central conductors 36 and 37 are configured to be accurately assembled to the plate-shaped magnetic body 35 at a predetermined angle.
Each of the center conductors 36 and 37 is wound around the surface of the plate-shaped magnetic body 35 so as to face the common electrode 40 with the highly dielectric plate-shaped magnetic body 35 interposed therebetween, thereby forming a microstrip line. Is done. Incidentally, referring to the positional relationship at the intersection of the first and second center conductors 36 to 38, as shown in FIG. 6, the second center conductor 37 is disposed closest to the plate-shaped magnetic body 35, and The first central conductor 36 is superimposed on the second central conductor 37, and the third central conductor 38 is further superimposed on the first central conductor 36. That is, the first center conductor 36 is arranged farther from the plate-shaped magnetic body 35 than the second center conductor 37 is.

The conductor width h1 of the first center conductor 36 is
By making the center conductor 37 narrower than the conductor width h2, the characteristic impedance of each of the center conductors 36 and 37 can be matched. That is, on the surface side of the plate-shaped magnetic body 35, the first center conductor 36 is
7, the conductor width h
The characteristic impedance is different when 1 and h2 are the same. However, by making the conductor width h1 smaller than the conductor width h2, the characteristic impedance of the first center conductor 36 becomes smaller than that of the second center conductor 37. Can be adjusted to impedance. Thereby, the insertion loss of the isolator 31 can be reduced, and the signal transmission efficiency can be improved.

The optimum relationship between the conductor widths h1 and h2 of the first and second center conductors 36 and 37 is (h2−h1) / h2 × 100 (%) for the same reason as in the first embodiment. )
Is preferably in the range of 10% or more and 20% or less, more preferably in the range of 14% or more and 17% or less. Next, a third central conductor 38 extends in the center of the common electrode 40 on the other long side 40a side. The third central conductor 38 is composed of a third base conductor 38 a protruding from the common electrode 40 and a third central conductor 3.
8b and a third tip conductor 38c.
The third base conductor 38a is composed of two strip-shaped divided conductors 38a1 and 38a2 extending substantially at right angles from the center of the long side of the common electrode 40, and includes two divided conductors 38a.
A slit 50 is formed between 1 and 38a2.
The third central conductor 38b includes an L-shaped divided conductor 38b1 connected to the preceding divided conductor 38a1 and an L-shaped divided conductor 38b2 connected to the preceding divided conductor 38a2. In order to increase the substantial conductor length of the divided conductors 38a1 and 38a2, the divided conductor 38b1 and the divided conductor 38b2 are extended from the divided conductors 38a1 and 38a2 so as to be separated from each other at the center thereof.
Although the diamond-shaped central conductor 38b is constituted by 1 and 38b2, the divided conductors 38b1 and 38b2 may be formed not in a diamond but in parallel and in an L-shape. . The conductor width of the third central conductor 38 is the same as the first and second central conductors 36 and 3.
7 may be the same as the conductor widths h1 and h2, or may be different from the conductor widths h1 and h2.

Further, these divided conductors 38b1, 38b
The front end side of 2 is integrated with an L-shaped third front end conductor 38c. The third distal end conductor 38c is formed by integrating the previous divided conductors 38b1 and 38b2 into one piece.
The connecting portion 38c1 is formed so as to extend in the same direction as a1 and 38a2, and the connecting portion 38c2 is formed so as to extend substantially perpendicular to the connecting portion 38c1.

Next, one long side portion 40a of the common electrode 40
On the side, the divided conductors 38a1 of the third center conductor 38,
The long sides 40a of the common electrode 40 are provided on both sides of the common electrode 38a2.
Are formed by partially notching the third central conductor 38. By forming these concave portions 40e, the line length of the third central conductor 38 is slightly increased, or sufficient inductance is provided for the third central conductor 38. Is secured, the concave portion 40e
Need not be provided. Further, the outer side of the two concave portions 40e on both sides of the three concave portions 40e in one long side portion 40a of the common electrode 40, in other words, the concave portion 40e and the inclined portion 40
c, a trapezoidal support piece 51 is formed extending in a direction parallel to the divided conductors 38a1 and 38a2, and also at the center of the common electrode 40 on the other long side 40a side. A support piece 52 having a rectangular shape in a plan view is extended.
These support pieces 51, 52 are used as ground electrodes of the capacitor substrates 41, 42, are electrically connected to one surface of the capacitor substrates 41, 42, and the other surface is connected to the tip conductors 36c, 37c as described later. , 38c, but if the capacitor substrates 41, 42 are directly adhered and conductive to the lower yoke 33, these support pieces 51, 5
2 is unnecessary.

In the common electrode 40 configured as described above, the main body 40A is attached to the back surface 15b side (one surface side) of the plate-shaped magnetic body 35, and the first center conductor 36 and the second center conductor 3
7 and the third center conductor 38 on the surface 15 of the plate-shaped magnetic body 35.
It is bent to the side a (the other side) and mounted on the plate-shaped magnetic body 35, and forms a magnetic assembly 45 together with the plate-shaped magnetic body 35. That is, the divided conductors 36a1 of the first center conductor 36,
36a2 is bent along the edge of one inclined surface 35d of the plate-shaped magnetic body 35, and the divided conductor 37a of the second center conductor 37 is bent.
1, 37a2 is the other inclined surface 35 of the plate-shaped magnetic body 35.
d, and the divided conductors 38a1 and 38a2 of the third center conductor 38 are bent along the edge of the long side 35a of the plate-shaped magnetic body 35, and the center conductor 3 of the first center conductor 36 is bent.
6a is attached to the surface side (the other surface side) of the plate-shaped magnetic body 35 along the diagonal line on the surface side of the plate-shaped magnetic body 35, and the center conductor 37b of the second center conductor 37 is connected to the surface side (the surface side of the plate-shaped magnetic body 35). The common electrode is attached to the other surface side along the diagonal line of the surface of the plate-shaped magnetic body, and the central conductor 38b of the third central conductor 38 is attached along the center of the surface of the plate-shaped magnetic body 35. 40 is mounted on the plate-like magnetic body 35 to form a magnetic assembly 45.

The diagonal line described here is
As shown in FIG. 8, when the plate-shaped magnetic body 35 is viewed in plan,
It is assumed that the position where the extension line of each long side 35a and each short side 35b intersects is the vertex of the substantially rectangular plate-shaped magnetic body 35,
Of the two vertices, a line segment connecting the opposing vertices is defined as diagonal lines L1 and L2. Further, the conductors 38b1, 38
b2 is disposed on the surface side of the plate-shaped magnetic body 35, and the length of the divided conductor 38b1 or the divided conductor 38b2 attached to the surface side of the plate-shaped magnetic body 35 is equal to that of the plate-shaped magnetic body 3 shown in FIG.
5 is preferably 105% or more of the vertical width (width along the width direction of the horizontally long rectangular plate-shaped magnetic body 35). By doing so, it is possible to increase the substantial conductor length of the divided conductors 38b1 and 38b2 to achieve both low frequency and miniaturization as a nonreciprocal circuit device.

As described above, the first to third central conductors 36,
By mounting the first and second central conductors 37 and 38 on the surface side of the plate-shaped magnetic body 35, the first center conductor 36 and the second center conductor 37 are individually diagonal lines L1 and L2 of the plate-shaped magnetic body 35 as shown in FIG. The first central conductor 36b and the second central conductor 37b are overlapped on the surface of the plate-shaped magnetic body 35 at an inclination angle of 120 ° in plan view. In the state where the first to third central conductors 36b, 37b, 38b overlap, the divided conductors 3 of the first central conductor 36b
6b1 and 36b2 and the portion where the divided conductors 37b1 and 37b2 of the second central conductor 37b are overlapped are all displaced in plan view on the surface side of the plate-shaped magnetic body 35, and are arranged so as to be divided. 36b2 and split conductor 37b
The portion where the first and 37b2 overlap is arranged on the surface of the plate-shaped magnetic body 35 so as not to overlap.

Further, the divided conductors 38b1 and 38b2 of the third central conductor 38b are arranged so as to avoid the portion where the divided conductors 36b1 and 36b2 overlap the divided conductors 37b1 and 37b2. Therefore,
On the surface of the plate-shaped magnetic body 35, the divided conductors 36b1,
36b2, divided conductors 37b1, 37b2, and divided conductor 38
Among these combinations, b1 and 38b2 may be arranged so as to be overlapped with each other, but are arranged so that a portion where three are overlapped does not occur. Although omitted in FIG. 6, the plate-shaped magnetic body 35, the first center conductor 36, the second center conductor 37, and the third center conductor 38 are respectively disposed between FIG.
As shown in FIG. 2, the respective center conductors 36, 37 and 38 are electrically insulated individually with an insulating sheet Z interposed therebetween.

Next, the magnetic assembly 45 is disposed at the center of the bottom of the lower yoke 33, and both sides of the magnetic assembly 45 on the bottom of the lower yoke 33 are elongated in a plan view and have a plate-like magnetic body 35,
The capacitor substrates 41 and 42 are stored in a plate shape having a thickness of about half of that of the capacitor substrate 42. A terminating resistor 43 is stored on one side of the capacitor substrate 42. More specifically, the length of the plate-shaped magnetic body 35 of the magnetic assembly 45 is formed substantially equal to the inner width of the lower yoke 33, and the width of the plate-shaped magnetic body 35 (the width in the direction orthogonal to the longitudinal direction). ) Is formed to be smaller than the inner width of the lower yoke 33, so that the plate-shaped magnetic body 35 is stored inside the lower yoke 33 so as to be horizontally long in plan view as shown in FIG. As shown in FIG. 6, spaces are formed on both sides in the width direction of the body 35 so that the capacitor boards 41 and 42 can be stored therein.
42 and a terminating resistor 43 are housed.

The tip conductor 36c of the first center conductor 36 is electrically connected to the electrode portion 41a formed at one end of the capacitor substrate 41, and the second center conductor 36c is connected to the electrode portion 41a. The tip conductor 37c of the conductor 37 is electrically connected to the electrode portion 41b formed on the other end of the capacitor substrate 41, and the tip conductor 38c of the third central conductor 38 is connected.
Are electrically connected to a capacitor substrate 42 and a terminating resistor 43, and capacitors 41 and 42 and a terminating resistor 4
3 are connected. If the terminating resistor 43 is not connected, it functions as a circulator.

A first port P1 as the non-reciprocal circuit element 31 is formed at the end of the capacitor board 41 to which the tip conductor 37c is connected, and the capacitor board 41 to which the tip conductor 36c is connected. A second port P2 as the non-reciprocal circuit element 31 is formed on the end side, and an end side of the terminating resistor 43 to which the tip conductor 38c is connected is set as a third port P3 as the non-reciprocal circuit element 31. I have.

The capacitor board 41 has a built-in capacitor C1 connected to the first central conductor 36 and a capacitor C2 connected to the second central conductor 37. The third central conductor 38 is provided on the capacitor substrate 42.
Is built in. As for the capacities Cap1 and Cap2 of the capacitors C1 and C2, the capacity Cap1 may be larger than the capacity Cap2.
It is preferable in terms of production to make the same. Further, the capacitance Cap3 of the capacitor C3 connected to the third center conductor 38 may be the same as one of the capacitances Cap1 and Cap2, or may be different from the capacitances Cap1 and Cap2. By making the capacitance Cap1 of the capacitor C1 larger than the capacitance Cap2, it is possible to make the center frequency of the reflection coefficient of the first center conductor 36 coincide with the center frequency of the reflection coefficient of the second center conductor 37. Thereby, the insertion loss can be reduced and the signal transmission efficiency can be improved.

In the space between the lower yoke 33 and the upper yoke 32, the magnetic assembly 45 is formed so as to occupy about half of the thickness of the space, and the upper yoke is larger than the magnetic assembly 45. A spacer member 60 is housed in the space on the side of the 32, and the permanent magnet 34 is installed in the spacer member 60.

The isolator 31 of the present embodiment shown in FIGS. 6 to 9 has the following effects in addition to the effects similar to the effects described in the first embodiment. That is, in the isolator 31 of the present embodiment, the first center conductor 36 and the second
Are bent via the planar receiving surfaces 35d, 35d of the plate-shaped magnetic body 35, and the third center conductor 38 is bent along the long side 35a of the plate-shaped magnetic body 35. Therefore, the bent portions of the center conductors 36b, 37b, 38b in the respective center conductors 36, 37, 38 have an accurate angle on the surface side of the plate-like magnetic body 35, for example, the first angle.
Of the center conductor 36 and the second center conductor 37
゜ is folded at an angle. That is, since the folding work is performed through the linear portion of the edge of the flat receiving surface 35d, the center conductors 36b and 37b are crossed at an angle of exactly 120 ° on the surface side of the plate-shaped magnetic body 35 and folded. You can easily tune. Therefore, a signal input from the input-side central conductor to the plate-shaped magnetic body 35 can be effectively propagated to the output side, and a low-loss and wide-band pass characteristic can be exhibited. Therefore, preferable magnetic characteristics of the magnetic assembly 45 can be reliably obtained.

The central conductors 36b, 37b, 38b folded on the surface side of the plate-like magnetic body 35 are superimposed as shown in FIG. 6, and in this superimposed state, the central conductors 36b, 37b, 38b Of each of the divided conductors 36b1, 36b2, 37b1, 37
Each of b2, 38b1, 38b2 is individually superimposed.
However, in the overlapped portion of these divided conductors 36b1 to 38b2, only two of the divided conductors are overlapped, and the three divided conductors are not overlapped. This is because the two center conductors 36 and 37 are divided into two parts,
This is because the central conductor 38b is formed into a two-part structure with the central conductor 38b expanded, so that the central conductor 38b can be prevented from overlapping with the central conductors 36b and 37b.

With such an overlapping structure, the three divided conductors can be prevented from overlapping each other, so that the center conductors 36b, 37b, 3b at the bottom of the spacer member 60 can be prevented.
8b is pressed against the plate-shaped magnetic body 35 when the center conductor 36
The overlapping portions of b, 37b, and 38b can be uniformly pressed. Here, for example, when a portion where three divided conductors overlap occurs, a portion where three divided conductors overlap is thicker than a portion where two divided conductors overlap, so that the spacer member 60 has strong strength in the three overlapped portions. While the pressing force is applied, the pressing force of the spacer member 60 is not sufficiently applied to the other two overlapping portions.
There is a high possibility that the pressing force may be applied evenly to b, 37b, and 38b to make it impossible to support all of them evenly. In addition, the height of the isolator 31 can be reduced, and the thickness can be reduced.

Further, by dividing the divided conductors 38b1 and 38b2 of the central conductor 38b so as to be non-parallel or parallel and bent or curved as described above, a signal inputted from the input-side central conductor is effectively reduced. And propagates on the plate-like magnetic body 35 made of high-frequency ferrite, and can output, thereby exhibiting a wide band pass characteristic. In order to reduce the frequency, each of the center conductors 36, 37, 38
It is necessary to increase the inductance by increasing
In the present invention, in the third central conductor 38b,
The third central conductor 38 is bent (bent) or curved in a direction away from each other on the central side in the longitudinal direction.
Alternatively, the third central conductor 38 is substantially parallel and bent or curved, whereby the length of the third central conductor 38 is substantially increased, the inductance is increased, and it is possible to achieve both low frequency and miniaturization. it can.

Next, in the present embodiment, the main body portion 40A of the electrode portion 46 has substantially the same planar view shape as the plate-like magnetic body 35, but by doing so, the lower portion where the main body portion 40A is located thereunder is formed. Since it is possible to contact the yoke 33 with a large area, the resistance is reduced and the loss can be reduced.

Next, as described above, concave portions 48a, 49a, and 40e are formed at the roots of the first center conductor 36, the second center conductor 37, and the third center conductor 38, respectively. Since the line length of each central conductor is slightly increased, the inductance of each central conductor 36, 37, 38 is increased, and the area of the resonance capacitance can be reduced. In other words, the area of the capacitor substrates 41, 42 can be reduced. This has an effect and contributes to downsizing of the entire non-reciprocal circuit device 31.

[0055]

EXAMPLE With respect to the isolator having the structure shown in FIGS. 6 and 7, S11, S22 and insertion loss S21 were measured when the conductor width of the first and second center conductors was changed. 6 and 7
In the isolator shown in the above, as the plate-like magnetic material,
A yttrium iron garnet ferrite (YIG ferrite) having a length of 2.0 mm, a width of 3.55 mm, and a thickness of 0.35 mm as shown in FIG. 8 was used. The first central conductor has a line length of 4 mm and a conductor width h.
1 is 500-600 μm, slit width is 100-200
A copper foil having a thickness of 0.05 mm and a thickness of 0.05 μm was used, and a copper foil having a line length of 4 mm, a conductor width h2 of 600 μm, a slit width of 200 μm and a thickness of 0.05 mm was used as the second central conductor. Further, as the third center conductor, a line length of 2.5 mm,
A copper foil having a conductor width h1 of 600 μm, a slit width of 400 μm and a thickness of 0.05 mm was used. These first, second,
As shown in FIG. 9, the third center conductor is 2.0 m long.
m, a width of 3.55 mm, and a thickness of 0.05 mm. A common electrode is attached to the bottom surface of the plate-shaped magnetic body, and the first, second, and third center conductors are bent toward the surface side of the plate-shaped magnetic body to form a magnetic assembly as shown in FIGS. Manufactured.
Next, the capacitor C1 is connected to the port P1 which is the tip of the first center conductor, the capacitor C2 is connected to the port P2 which is the tip of the second center conductor, and the port P3 which is the tip of the third center conductor.
A capacitor C3 is attached to each of the capacitors C3, a terminating resistor R is attached to the capacitor C3, and a permanent magnet is attached to the plate-shaped magnetic body, which is then arranged in a closed magnetic circuit composed of an upper yoke and a lower yoke. 6 and FIG.
The isolators of Experimental Examples 1 and 2 shown in FIG.

For the above isolator, S11, S2
2. The strength of the insertion loss S21 was determined. Table 1 shows the results
Shown in

[0057]

[Table 1]

As shown in Table 1, in the isolator of Experimental Example 1, the insertion loss S21 was 0.52 dB because the conductor width of the first center conductor was smaller than the conductor width of the second center conductor.
And relatively low. In addition, S11 and S22 are relatively high numerical values, which indicates that the matching of the characteristic impedance is good. The ratio of the conductor width difference of the isolator of Experimental Example 1 was about 17%.
On the other hand, in the isolator of Experimental Example 2, the conductor width of the first center conductor was made equal to the conductor width of the second center conductor,
The insertion loss S21 is relatively high at 0.62 dB.
Also, S11 and S22 have relatively low numerical values, indicating that the matching of the characteristic impedance is not so much improved.

[0059]

As described above in detail, according to the non-reciprocal circuit device of the present invention, the conductor width of one center conductor that intersects on the side away from the plate-like magnetic body is set to the plate-like magnetic body. By making the conductor width narrower than the conductor width of the other center conductor that intersects on the near side, the characteristic impedance of the pair of center conductors can be matched (matching), thereby reducing the insertion loss of the nonreciprocal circuit device and reducing the signal loss. Transmission efficiency can be improved.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a main part of an isolator according to a first embodiment of the present invention.

FIG. 2 is a developed view of a common electrode and first, second, and third center conductors of the isolator shown in FIG.

FIG. 3 is an exploded perspective view showing the isolator according to the first embodiment of the present invention.

FIG. 4 is a circuit diagram showing an example of a circuit configuration of a mobile phone device in which the isolator according to the first embodiment of the present invention is incorporated.

FIG. 5 is a schematic view showing the operation principle of the isolator according to the first embodiment of the present invention.

FIG. 6 is a plan view showing a state where a part of an isolator according to a second embodiment of the present invention has been removed.

FIG. 7 is a sectional view showing an isolator according to a second embodiment of the present invention.

FIG. 8 is a plan view showing an example of a plate-shaped magnetic body used for an isolator according to a second embodiment of the present invention.

FIG. 9 is a developed view of an electrode unit used in an isolator according to a second embodiment of the present invention.

FIG. 10 is a perspective view showing a main part of a conventional isolator.

[Explanation of symbols]

1,31 Isolator (Non-reciprocal circuit device) 11, 36 1st center conductor (one center conductor) 12, 37 2nd center conductor (the other center conductor) 13, 38 Third center conductor 14, 40 Common electrode 15, 35 plate-shaped magnetic material 15a other side 15b one side 21, 32 Upper yoke (case body) 22, 33 Lower yoke (case body) C1, C2, C3 capacitors h1 Conductor width of first center conductor h2 Conductor width of second center conductor R terminal resistor (resistance element)

   ────────────────────────────────────────────────── ─── Continuation of front page    (72) Inventor Eiichi Komai             Alp, 1-7 Yukitani-Otsuka-cho, Ota-ku, Tokyo             SU Electric Co., Ltd. (72) Inventor Hitoshi Onishi             Alp, 1-7 Yukitani-Otsuka-cho, Ota-ku, Tokyo             SU Electric Co., Ltd. F-term (reference) 5J013 EA01 FA05

Claims (3)

[Claims] 1. A common electrode is arranged on one surface side of a plate-shaped magnetic body, and is formed to extend in three directions from an outer peripheral portion of the common electrode.
The two center conductors are bent to the other side of the plate-shaped magnetic body so as to enclose the plate-shaped magnetic body, and the respective center conductors cross each other at a predetermined angle on the other side, and A capacitor is connected to one end of each of the conductors. One of the three center conductors intersects on one side of the pair of center conductors on a side away from the plate-shaped magnetic body. Wherein the width of the conductor is smaller than the width of the other center conductor. 2. When the conductor width of the one central conductor is h1 and the conductor width of the other central conductor is h2,
2. The non-reciprocal circuit device according to claim 1, wherein a ratio of a difference represented by (h 2 −h 1) / h 2 × 100 (%) is in a range of 10% or more and 20% or less. 3. The non-reciprocal circuit device according to claim 1, wherein the pair of central conductors is an input / output terminal.