JP2002353706A - Center electrode assembly, irreversible circuit element and communication unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a center electrode assembly with enhanced electric characteristics and reliability having a low profile and to provide an irreversible circuit element and a communication unit. SOLUTION: The center electrode assembly 1 comprises a rectangular microwave ferrite 10, a center conductor 20 and an insulation sheet 28 or the like. The center conductor 20 comprises center electrodes 21-23 and an earth electrode 25 or the like. The center conductor 20 is integrally formed by punching processing or the like. The center conductor electrodes 21-23 are crossed in the center of an upper side 11 of the ferrite 10. A recessed part 13 is formed at the cross point. In the center electrode assembly 1, the ferrite 10 is placed on the earth electrode 25. Further, the center conductor electrode 21, the insulation sheet 28, the center conductor electrode 22, the insulation sheet 28, the center conductor electrode 23 and the insulation sheet 28 are layered in the order and the layered electrodes and sheets are wound on the ferrite 10. The insulation sheet 28 prevents the center conductor electrodes 21-23 from being short-circuited.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a center electrode assembly such as an isolator and a circulator used in a microwave band, a nonreciprocal circuit device, and a communication device.

[0002]

2. Description of the Related Art In general, a lumped constant type isolator employed in a mobile communication device such as a portable telephone has a function of passing a signal only in a transmission direction and preventing transmission in a reverse direction. In recent mobile communication devices, there is a strong demand for thinner sets, higher performance, and lower cost for their applications, and the thickness of the isolator is mainly 2.0 mm or less. It has become. Accordingly, the height of the center electrode assembly built in the isolator is also required to be reduced.

FIG. 10 shows a known center electrode assembly of this type. The center electrode assembly 200 includes three center electrodes 201 to 2 on an upper surface 207a of the microwave ferrite 207 with three insulating sheets 208 interposed therebetween.
03 are arranged at predetermined angles and cross each other. One end of each of the center electrodes 201 to 203 is led out horizontally as a port P. Further, the other ends of the center electrodes 201 to 203 are connected to the respective center electrodes 201 to 20.
It is connected to three common ground electrodes 204. The ground electrode 204 is in contact with the lower surface 207b of the ferrite 207, and substantially covers the lower surface 207b of the ferrite 207.

However, the upper surface 207a of the ferrite 207
Since the center electrodes 201 to 203 (representative thickness dimension of each center electrode: 50 μm) are stacked at the center, the center electrode assembly 200 is thicker at the center than at the outer periphery.
The thickness difference between the outer peripheral portion and the central portion (the insulating sheet 2
Representative thickness difference including thickness of 08: 100 μm
Above), which is an obstacle to lowering the height.

To reduce the height, it is conceivable to reduce the thickness of the ferrite 207. However, when the ferrite 207 is thinned, the distance between the center electrodes 201 to 203 and the ground electrode 204 disposed on the lower surface 207b of the ferrite 207 is reduced, so that the Q value of the isolator is deteriorated and the insertion loss is increased. Further, when a DC magnetic field is applied to the ferrite 207 having a small thickness, the demagnetizing coefficient increases, and there is a concern that the magnetic force may be insufficient.

[0006] To solve this problem, Japanese Utility Model Application Laid-Open No.
A non-reciprocal circuit device described in -84611 has been proposed. As shown in FIG. 11, the center electrode assembly 210 of the main part of this non-reciprocal circuit device has center electrodes 211 to 213 sandwiched between ferrite 214 and ferrite 215. The ferrites 214 and 215 are disc-shaped in plan view, and have through holes 214a and 215a at the center, respectively.

The center electrodes 211 to 213 are arranged on the same plane between the two ferrites 214 and 215 so as to form an angle of about 120 degrees with each other. The central part 211 of the center electrodes 211 to 213
c to 213c are three-dimensionally crossed so as not to contact each other. That is, the central portion 211c of the center electrode 211
In contrast, the central portions 212c and 213c of the center electrodes 212 and 213 arranged above and below the center electrode 211 are bent in a U-shape, respectively, to avoid electrical contact between the center electrodes 211 to 213. Further, the central portions 212c, 2
13c is bent in a direction away from the center portion 211c of the center electrode 211, so that the center portion 212c
Into the through hole 214a and the central part 213c into the through hole 215a.
To accommodate each. Central part 211c, 212c, 21
3c crosses three-dimensionally in the through holes 214a and 215a.

[0008]

However, the center electrode 21
The central portions 211c to 213c of the central electrodes 1 to 213 are not subjected to insulation treatment or the like, and the central portions 212c and
Since we just bent 213c and crossed it three-dimensionally,
The center electrodes 211 to 213 may be in contact (short).

Further, since the center electrodes 211 to 213 before being incorporated into the center electrode assembly 210 are independent individual electrode parts, one end of each of the center electrodes 211 to 213 is connected to the ground side, and the other is connected to the ground. The end must be connected to the signal side (hot side). For this connection, a solder joint is used. Therefore, there are many solder joints, and there is a concern that connection reliability may be reduced.

An object of the present invention is to provide a center electrode assembly, a non-reciprocal circuit device, and a communication device having improved electrical characteristics and reliability and a reduced height.

[0011]

In order to achieve the above object, a center electrode assembly according to the present invention comprises: (a) a first electrode;
(B) a ground electrode disposed on a second main surface opposite to the first main surface of the ferrite, and a first ferrite extending from the ground electrode. A center conductor having a plurality of center electrodes disposed on a main surface of each other via an insulating sheet and at a predetermined crossing angle; and (c) providing the concave portion at least at a position where the center electrodes cross each other. It is characterized by the following.

Further, the center electrode assembly according to the present invention comprises:
(D) a ferrite having a through-hole passing through the first main surface and a second main surface facing the first main surface;
An earth electrode disposed on a second main surface of the ferrite;
A center conductor extending from the ground electrode and having a plurality of center electrodes disposed on the ferrite via an insulating sheet and at a predetermined crossing angle; and (f) at least the center electrodes cross each other. Wherein the through hole is provided at a position where the through hole is located.

According to the above configuration, since the respective center electrodes are arranged on the first main surface of the ferrite via the insulating sheet, there is no fear that the respective center electrodes are short-circuited. Further, the plurality of center electrodes arranged and stacked on the first main surface of the ferrite at a predetermined crossing angle via an insulating sheet are thick at the center and thin at the outer periphery. Therefore, the center electrode assembly is reduced in height because the concave portion and the through hole absorb the difference in thickness between the central portion and the outer peripheral portion. Further, since the center conductor in which the center electrode and the ground electrode are integrated is used, the number of solder joints is reduced as compared with the conventional center electrode assembly 210 shown in FIG.

In the nonreciprocal circuit device according to the present invention, only the portion of the first main surface of the ferrite where the center electrode intersects is arranged in the concave portion or the through hole, so that it is arranged on the first main surface. The distance between the center electrode and the ground electrode disposed on the second main surface is increased to prevent deterioration of the Q value and insertion loss of the non-reciprocal circuit device. Further, since the thickness of the ferrite is increased, an increase in the demagnetizing factor of the non-reciprocal circuit device is suppressed, a magnetic force shortage is prevented, and highly reliable electrical characteristics can be obtained.

Further, the communication device according to the present invention is provided with the non-reciprocal circuit device having the above-mentioned features, so that the height can be reduced, and high reliability can be obtained at low cost.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of a center electrode assembly, a non-reciprocal circuit device, and a communication device according to the present invention will be described with reference to the accompanying drawings. In each embodiment, the same components and the same portions are denoted by the same reference numerals, and a duplicate description will be omitted.

[First Embodiment, FIGS. 1 to 3] FIG. 1 is an exploded perspective view of a center electrode assembly according to the present invention. FIG.
FIG. 2 shows an external perspective view of the center electrode assembly 1 shown in FIG. 1 after assembly is completed. FIG. 3 shows the center electrode assembly 1 shown in FIG.
III-III sectional view of FIG.

As shown in FIG. 1, the center electrode assembly 1 includes
It comprises a rectangular microwave ferrite 10, a central conductor 20, an insulating sheet 28 and the like. The center conductor 20 is the center electrode 2
One end of each of the center electrodes 21 to 23 is a port portion P1 to P3, and the other end is connected to the ground electrode 25. The center conductor 20 is integrally formed by punching or etching a thin metal plate (the center conductor 20, that is, the center electrodes 21 to 23 and the representative thickness of the ground electrode 25: 50 μm). A recess 13 is formed in the center of the upper surface 11 of the ferrite 10. Recess 1
3, the depth dimension of the center electrodes 21 to 23, as described later.
Are set to a depth dimension corresponding to a thickness of about two (representative depth dimension: 100 μm).

The center electrode assembly 1 is assembled, for example, by the following procedure. As shown in FIG. 1A, the ferrite 10 is placed on the ground electrode 25. Then, as shown in FIG. 1 (B), the center electrode 21 is wound around the upper surface 11 of the ferrite 10, and the insulating sheet 28 is placed thereon. Further, as shown in FIG. 1C, the center electrode 22, the insulating sheet 28, the center electrode 23, the insulating sheet 28
Are wound in order on the ferrite 10. The insulating sheet 28 is laminated between the center electrodes 21 to 23 in order to prevent a short circuit between the center electrodes 21 to 23.

Thus, the center electrode assembly 1 as shown in FIG. 2 is obtained. The center electrode assembly 1 has the center electrodes 21 to 23 arranged on the upper surface 11 of the ferrite 10 so as to intersect approximately every 120 degrees. These center electrodes 21 to 23 horizontally lead out port portions P1 to P3 on one end side, respectively. Further, the ground electrode 25 is connected to the lower surface 1 of the ferrite 10.
2 and substantially covers the lower surface 12 of the ferrite 10.

Further, as shown in FIG.
A central portion of the insulating sheet 28 disposed on the upper surface 11 of the
That is, at the position where the center electrodes 21 to 23 intersect, the three insulating sheets 28 and the center electrodes 21 to 23 are laminated. At the outer peripheral portion of the insulating sheet 28 disposed on the upper surface 11, that is, at a position where the center electrodes 21 to 23 do not intersect, one of the three insulating sheets 28 and the center electrodes 21 to 23 is laminated. Accordingly, the difference in thickness between the central portion and the outer peripheral portion is equal to the total thickness of the two central electrodes 21 to 23 (representative thickness: 100 μm). That is,
In the first embodiment, the difference in thickness between the central portion and the outer peripheral portion is set so that the depth of the concave portion 13 is approximately equal.

Further, a portion where the center electrodes 21 and 22 mounted and laminated on the upper surface 11 of the ferrite 10 and the insulating sheet 28 sandwiched between the center electrode 21 and the center electrode 22 overlaps with the recess 13 Since the ferrite 10 is housed inside, the entire upper surface 11 of the ferrite 10 becomes flat.

The above-mentioned center electrode assembly 1 is composed of a ferrite 1
The center electrodes 21 to 23 are placed on the insulating sheet 28
, The center electrodes 21 to 23 are not easily short-circuited to each other. In addition, since the center conductor 20 in which the center electrodes 21 to 23 and the ground electrode 25 are integrated is used, soldering between the center electrodes 21 to 23 and the ground electrode 25 can be omitted. Further, since the overlapping portion of the center electrodes 21 to 23 is accommodated in the recess 13, the center electrode assembly 1
Can be reduced in thickness.

The center electrode assembly 1 includes a ferrite 1
Since only the portions of the upper surface 11 where the center electrodes 21 to 23 intersect are arranged in the recesses 13, the center electrodes 21 to 23 arranged on the upper surface 11 and the ground electrodes 25 arranged on the lower surface 12 are separated. The electrode spacing can be increased. Therefore, the center electrode assembly 1 can prevent deterioration of the Q value and the insertion loss.

[Second Embodiment, FIG. 4] In the second embodiment, a modification of the center electrode assembly 1 shown in the first embodiment is shown. FIG. 4 is a vertical sectional view of the center electrode assembly 1a.

As shown in FIG. 4, the center electrode assembly 1a
Is composed of the ferrite 10a and the center conductor 20 shown in the first embodiment. The upper surface 11 of the ferrite 10a has a tapered recess 13a. Center electrode 21
23 are arranged so as to follow the surface of the concave portion 13a.

The above-described center electrode assembly 1a has the same operation and effect as the center electrode assembly 1 of the first embodiment.
Further, since the shape of the recess 13a of the ferrite 10a is tapered, the thickness of the ferrite 10a changes continuously. Accordingly, since the change in the distance between the permanent magnet that applies a DC magnetic field to the ferrite 10a when incorporated in the isolator and the center electrodes 21 to 23 becomes slow, the electric and magnetic changes of the center electrodes 21 to 23 are reduced. It is slow, and the electrical characteristics of the center electrode assembly 1a are not easily deteriorated.

[Third Embodiment, FIG. 5] In the third embodiment, a modification of the center electrode assembly 1 shown in the first embodiment is shown. FIG. 5 is a vertical sectional view of the center electrode assembly 1b.

As shown in FIG. 5, the center electrode assembly 1b
Is a ferrite 1 having a through hole 13b formed in the center.
0b and the center conductor 20. In the third embodiment,
The size of the through hole 13b in a plan view was set to be substantially the same as the size of the recess 13 shown in the first embodiment in a plan view.

The above-described center electrode assembly 1b has the same operation and effect as the center electrode assembly 1 shown in the first embodiment and the center electrode assembly 1a shown in the second embodiment. Furthermore, since the through hole 13b is formed in the ferrite 10b used for the center electrode assembly 1b,
A sufficient depth is provided for accommodating overlapping portions of the center electrodes 21 to 23.

Further, it is necessary to change the thickness of the center electrodes 21 to 23 according to the frequency band in which the center electrode assembly 1b is used. At this time, in the center electrode assemblies 1 and 1a shown in the first embodiment and the second embodiment, the center electrode 2
It is necessary to change the depth of the concave portions 13 and 13a in accordance with the thickness of the concave portions 1 to 23. However, in the center electrode assembly 1b of the third embodiment, since the through-hole 13b having a sufficient depth is formed in the ferrite 10b,
By simply increasing or decreasing the thickness of the center electrodes 21 to 23 without changing the shape of b, the electrical characteristics of the center electrode assembly 1b can be easily changed.

Further, since the ferrite 10b having the through hole 13b has no vertical direction, the ferrite 10b
When placing the ferrite 10b on the center conductor 20, the step of checking the upper and lower sides of the ferrite 10b can be omitted.

[Fourth Embodiment, FIGS. 6 to 8] In the fourth embodiment, a lumped-constant isolator provided with the center electrode assembly 1 of the first embodiment will be described as an example. FIG.
1 shows an exploded perspective view of a non-reciprocal circuit device 2 according to the present invention. FIG. 7 is a perspective view showing the appearance of the non-reciprocal circuit device 2 shown in FIG. 6 after assembly is completed. The non-reciprocal circuit device 2 is a lumped constant type isolator.

As shown in FIG. 6, the lumped-constant isolator 2 includes a lower case 4, an upper case 8, a resin case 3, the center electrode assembly 1 shown in the first embodiment, and a permanent case. It includes a magnet 9, a resistance element R, matching capacitor elements C1 to C3, and the like.

The lower case 4 includes a bottom wall 4a and left and right side walls 4a.
b. The upper case 8 has a rectangular shape in a plan view, and has an upper wall 8a and four side walls 8b. The lower case 4 and the upper case 8 are obtained by punching and bending a thin plate made of a material containing iron as a main component, and then performing copper plating or silver plating.

The resin case 3 has a bottom wall 3a and four side walls 3
b. A rectangular insertion window 3c is formed at the center of the bottom wall 3a. Also, in the resin case 3,
The input terminal 14, the output terminal 15, and the ground terminal 16 are insert-molded. One end of the input terminal 14 is exposed on the outer surface of the side wall 3b, and the other end is exposed on the inner surface of the bottom wall 3a to form an input lead electrode 14a. Output terminal 15
Has one end exposed to the outer surface of the side wall 3b and the other end exposed to the inner surface of the bottom wall 3a to form an output extraction electrode 15a.
One end of each of the two ground terminals 16 is exposed on the outer surface of the opposing side wall 3b, and the other end is exposed on the bottom surface of the concave portion 3d formed on the bottom wall 3a to form an earth terminal electrode 16a.

Each of the matching capacitor elements C1 to C3 has a hot-side capacitor electrode on the entire upper surface and a cold-side capacitor electrode on the entire lower surface.

The resistance element R has a ground-side terminal electrode and a hot-side terminal electrode formed on both ends of an insulating substrate by thick film printing or the like, and a resistor is disposed between them.

The above components are assembled as follows. After the resin case 3 is assembled in the lower case 4, the center electrode assembly 1, the matching capacitor elements C1 to C3, the resistance element R, and the like are housed in the resin case 3.

The center electrode assembly 1 is inserted through the insertion window 3c. The ground electrode 25 of the center electrode assembly 1 is
is connected to the bottom wall 4a of the lower case 4 exposed at the point c by soldering or the like and grounded. The port P1 of the center electrode 21 is electrically connected to the input extraction electrode 14a, and the port P2 of the center electrode 22 is electrically connected to the output extraction electrode 15a by solder reflow, wire bonding, or the like.

The hot-side terminal electrode of the resistance element R is electrically connected to the port P3 by solder reflow, wire bonding, or the like. The ground terminal electrode is soldered to the ground terminal electrode 16a exposed in the recess 3d of the resin case 3. The hot-side capacitor electrodes of the matching capacitor elements C1 to C3 are electrically connected to the port portions P1 to P3 by solder reflow, wire bonding, or the like.
The cold-side capacitor electrodes are soldered to the ground terminal electrodes 16a of the ground terminals 16, respectively. That is, the matching capacitor element C3 and the resistance element R are connected to the center electrode 2
3 is electrically connected in parallel between the port portion P3 and the ground terminal 16 (see FIG. 8).

Further, after the permanent magnet 9 is disposed below the upper wall 8a of the upper case 8, the upper case 8 is mounted. At this time, the permanent magnet 9 applies a DC magnetic field to the ferrite 10. The lower case 4 and the upper case 8 are connected to the side walls 4b, 8b.
To form a metal circuit, form a magnetic circuit, and also function as a yoke.

Thus, the isolator 2 shown in FIG. 7 is obtained. FIG. 8 is an electrical equivalent circuit diagram of the isolator 2.

Since the isolator 2 includes the center electrode assembly 1 of the first embodiment, the same effect can be obtained. Furthermore, electrical characteristics and quality are stable, and
Manufacturing costs are low. In addition, the center electrodes 21 to
Since the distance between the electrode 23 and the ground electrode 25 is increased, an increase in the demagnetizing coefficient of the isolator 2 is suppressed, and highly reliable electrical characteristics can be obtained.

[Fifth Embodiment, FIG. 9] In the fifth embodiment, a mobile phone will be described as an example of a communication device according to the present invention.

FIG. 9 is an electric circuit block diagram of the RF portion of the mobile phone 120. In FIG. 9, 122 is an antenna element, 123 is a duplexer, 131 is a transmitting side isolator, 132 is a transmitting side amplifier, 133 is a band pass filter for transmitting side interstage, 134 is a transmitting side mixer, 135 is a receiving side amplifier, and 136 is a receiving side amplifier. Bandpass filter for interstage on the receiving side, 1
37 is a mixer on the receiving side, 138 is a voltage controlled oscillator (VC
O) 139 is a local band-pass filter.

Here, the lumped-constant isolator 2 of the fourth embodiment can be used as the transmission-side isolator 131. By mounting this isolator 2, it is possible to obtain a communication device with stable electrical characteristics and quality and low manufacturing cost.

[Other Embodiments] The present invention is not limited to the above-described embodiment, and can be modified into various configurations within the scope of the present invention. For example, in the fourth embodiment, the center electrode assembly 1 shown in the first embodiment is adopted as the isolator 2, but the center electrode assemblies 1a and 1b shown in the second and third embodiments are used. May be adopted.

In the fourth embodiment, the present invention is applied to an isolator. However, the present invention can be applied to a circulator and other high-frequency components.

The intersection angle of each of the center electrodes 21 to 23 may be in the range of 110 to 140 degrees. Further, the metal case may be divided into three or more. Also, the ferrite 10, the recesses 13, 13a, and the through holes 13b
Is not limited to a rectangular shape in plan view, and may be another shape such as a circular shape or a hexagonal shape. Further, the permanent magnet 9 is not limited to a disk shape, but may be another shape such as a rectangular parallelepiped shape or a hexagonal shape. Further, the recesses 13 and 13a of the ferrite 10 shown in the first and second embodiments.
Is not particularly limited as long as it can accommodate the overlapping portion of the center electrodes 21 to 23.

[0051]

As is apparent from the above description, according to the present invention, the concave portion and the through-hole provided in the ferrite absorb the thickness of the portion where the plurality of center electrodes overlap, so that the center electrode assembly is formed. Can be reduced in height.

Since only the portion of the first main surface of the ferrite where the center electrode intersects is arranged in the recess or through hole,
It is possible to increase the electrode interval between the center electrode disposed on the first main surface and the ground electrode disposed on the second main surface, thereby preventing deterioration of the Q value and insertion loss. Further, by increasing the electrode spacing, an increase in the demagnetizing field coefficient of the nonreciprocal circuit device can be suppressed, and highly reliable electrical characteristics can be obtained.

Further, the communication device according to the present invention is provided with the non-reciprocal circuit device having the above-mentioned features, so that the height is reduced.
And high reliability can be obtained at low cost.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view showing a first embodiment of a center electrode assembly according to the present invention.

FIG. 2 is an external perspective view of the center electrode assembly shown in FIG. 1 after assembly is completed.

FIG. 3 is a sectional view of the center electrode assembly shown in FIG. 2;
Sectional view.

FIG. 4 is a sectional view showing a second embodiment of the center electrode assembly according to the present invention.

FIG. 5 is a sectional view showing a third embodiment of the center electrode assembly according to the present invention.

FIG. 6 is an exploded perspective view showing one embodiment of the non-reciprocal circuit device according to the present invention.

FIG. 7 is an external perspective view after the assembly of the non-reciprocal circuit device shown in FIG. 6 is completed.

8 is an electrical equivalent circuit diagram of the non-reciprocal circuit device shown in FIG.

FIG. 9 is an electric circuit block diagram showing one embodiment of a communication device according to the present invention.

FIG. 10 is an external perspective view of a conventional center electrode assembly.

FIG. 11 is an exploded perspective view of another conventional center electrode assembly.

[Explanation of symbols]

 1, 1a, 1b Central electrode assembly 2 Lumped constant type isolator (non-reciprocal circuit element) 4 Lower case (metal case) 8 Upper case (metal case) 9 Permanent magnet 10, 10a, 10b Micro Wave ferrite 11 top surface (first main surface) 12 bottom surface (second main surface) 13, 13a recess 13b through hole 20 central conductor 21 to 23 central electrode 25 earth electrode 28 insulating sheet 120 mobile Telephone (communication device)

Claims (4)

[Claims] A ferrite having a concave portion formed in a first main surface; a ground electrode disposed on a second main surface of the ferrite opposed to the first main surface; and a ferrite extending from the ground electrode. A center conductor having a plurality of center electrodes disposed on the first main surface of the ferrite via an insulating sheet and at a predetermined crossing angle, and the concave portion is provided at least at a position where the center electrodes cross each other. A center electrode assembly, characterized in that: 2. A first main surface and a second main surface facing the first main surface.
A ferrite having a through-hole passing through the main surface; a ground electrode disposed on a second main surface of the ferrite;
A center conductor extending from the ground electrode and having a plurality of center electrodes disposed on the ferrite via an insulating sheet and at a predetermined crossing angle, at least at a position where the center electrodes cross each other. A center electrode assembly provided with the through hole. 3. A metal case for housing the permanent magnet, the center electrode assembly according to claim 1, wherein a DC magnetic field is applied by the permanent magnet, and the permanent magnet and the center electrode assembly. And a non-reciprocal circuit device comprising: 4. A communication device comprising the non-reciprocal circuit device according to claim 3.