JP3331701B2 - Non-reciprocal circuit device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to VHF, UHF, SH
Regarding non-reciprocal circuit elements used in the F-band and the like, for example, isolators, in particular, it is possible to reduce the size and weight of components and to contribute to cost reduction while widening the isolation characteristics. Regarding the structure.

[0002]

2. Description of the Related Art Generally, an isolator has a function of passing a signal only in a transmission direction and preventing transmission in a reverse direction. For example, an isolator is used in a transmission circuit section of a mobile communication device such as a mobile phone and a car phone. Have been. This isolator is
As shown in FIG. 11, a terminating resistor R is connected to any one of the ports P3 of the circulators of the three ports P1 to P3, and the signal a from the port P1 is transmitted to the port P2. It has a function of absorbing the incoming reflected wave b by the terminating resistor R to prevent transmission to the port P1, thereby preventing unnecessary waves from entering the power amplifier.

In the above isolator, the port P
Depending on the frequency of the reflected wave b entering from 2, there is a case where the reflected wave b cannot be absorbed, and as a result, the problem that the reflected wave b escapes to the port P1 occurs. In order to avoid such a problem, an attempt is made to broaden the isolation characteristic (reverse attenuation characteristic).

On the other hand, as shown in FIG.
To P3, a matching circuit 1 composed of L (inductance), C (capacitor) and the like is connected.
There is a method of widening the pass bandwidth of P3. However, if matching circuits 1 and 1 are provided on the lines of ports P1 and P2 through which signals pass, the loss increases and I.P. L. There is a problem that characteristics (pass characteristics) are deteriorated, and there is a problem that an increase in the number of parts and an increase in the size and weight of the parts are caused.

On the other hand, as shown in FIG. 9, between the terminating resistor R and the port P3 (see FIG. 9A) or between the terminating resistor R and the cold end (see FIG. )reference)
It is conceivable that the matching circuit 1 is provided in the first embodiment to thereby broaden only the isolation characteristic. In this case, the loss in the signal line can be reduced, and I.I. L. Deterioration of the characteristics can be avoided, and reduction in size and weight can be achieved by reducing the number of parts.

FIGS. 4 to 8 show an example of a structure in which a matching circuit is provided to the terminating resistor. The isolator 2 mainly accommodates a matching capacitance substrate 5 and a ferrite element 6 with a ground plate 17 interposed in magnetic yoke bodies 3 and 4 forming a magnetic closed circuit, and is attached to the inner surface of the yoke 3. A DC magnetic field is applied to the ferrite element 6 by the attached permanent magnet 7, and a terminal board 8 is provided outside the yoke 4.

FIGS. 4 and 5 show that a matching circuit element 11 is composed of a coil 9 and a disk type capacitor 10, and one end of the circuit element 11 is connected to a terminating resistance film 5 a of the capacitor substrate 5.
And the other end is connected to the yoke 4.

FIGS. 6 and 7 show that a matching circuit board 14 is formed by patterning a microstrip line 13 on the surface of a substrate 12 and that the circuit board 14 is mounted on the yoke 3. One end of 13
This is an example in which 3a and the terminating resistance film 5a of the capacitance substrate 5 are connected via a metal plate 15, and the other end 13b is connected to the yoke 3 via a through-hole electrode. Further FIG.
Constitutes a matching circuit board 16 by superimposing boards on which a strip line (not shown) is formed.
This is an example of mounting on the upper part.

[0009]

However, in each of the above-described structural examples, since the matching circuit element and the matching circuit board are separately mounted on the yoke main body, the size and weight of the parts cannot be increased accordingly. Inevitably, there is a problem that it is impossible to cope with miniaturization and weight reduction, and improvement in this respect is demanded.

Further, when a matching circuit element using the above-mentioned coil and disk capacitor is employed, the constant tends to be unstable, so that it is necessary to adjust the electrical characteristics, which is troublesome, resulting in an increase in cost. There is.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and can cope with downsizing and weight reduction of components while widening the isolation, and simplify the adjustment of electrical characteristics to reduce costs. It is intended to provide a non-reciprocal circuit device that can be used.

[0012]

According to the present invention, a plurality of center conductors are arranged in a ferrite to which a DC magnetic field is applied in a state of being electrically insulated from each other and crossing each other. A non-reciprocal circuit device having a capacitor connected thereto, a terminator connected to any one of the ports, and a matching circuit connected to the terminator so as to achieve a wider isolation characteristic. Electrical length is 1/4
A line having an integral multiple of λg (λg is a wavelength in the line) is used, and the line is formed as a strip line on a thin substrate, and the thin substrate is used for a matching capacitor constituting the non-reciprocal circuit device. It is characterized in that it is laminated inside the substrate.

[0013]

According to the non-reciprocal circuit device of the present invention, a strip line having an electrical length of 1 / 4.lambda.g is connected to a terminator connected to one port, and the strip line is formed on a thin substrate by pattern formation. Then, since the thin substrate was laminated in the matching capacity substrate, I.I. L. It is possible to broaden the isolation characteristic while avoiding the influence on the characteristic, and it is possible to reliably absorb the reflected wave and prevent an unnecessary wave from entering.

Since the above-mentioned thin board is incorporated in the capacity board constituting the non-reciprocal circuit device, the existing board can be used as it is, so that the size, volume and weight of the component hardly increase. Therefore, it is possible to cope with downsizing and weight reduction of parts as compared with the case where the above-mentioned matching circuit element or matching circuit board is separately mounted.

Further, in the present invention, since it is only necessary to manage the line length of the strip line, it is possible to configure a high-precision broadband circuit having less variation as compared with the case of using a circuit element including the coil and the disk capacitor. it can. Along with this, it is possible to simplify the electrical adjustment or to eliminate the adjustment, thereby reducing the cost and contributing to the cost reduction of parts.

[0016]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. FIGS. 1 to 3 are diagrams for explaining a non-reciprocal circuit device according to an embodiment of the present invention. In this embodiment, a case where the present invention is applied to a lumped constant type isolator will be described as an example.

In the figure, reference numeral 20 denotes a lumped constant type isolator to which the structure of the present embodiment is applied. The isolator 20 includes a lower yoke 22 made of a substantially U-shaped magnetic metal disposed on a terminal board 21, and a bottom wall 22 a of the lower yoke 22.
In addition to disposing a matching capacitance substrate 23 described later,
A ferrite element 24 is provided, and an upper yoke 25 made of a magnetic metal is mounted on the lower yoke 22 to form a magnetic circuit of a closed magnetic circuit. A permanent magnet 26 is attached to the inner surface of the upper yoke 25, and the permanent magnet 2
6, a bias DC magnetic field is applied to the ferrite element 24.

A ground electrode 36 is provided on the upper surface of the terminal board 21.
a is formed, and the lower surface of the lower yoke 22 is in contact with the ground electrode 36a. Ground terminal electrodes 37a and 37b connected to the ground electrode 36a are formed on the upper and lower surfaces of the left and right side edges of the terminal board 21, and the terminal electrodes 37a and 37b are connected to the side electrodes 38. Connected by

The input / output terminal electrodes 32a, 32a are provided on the upper and lower surfaces of the left and right side edges of the terminal board 21, respectively.
2b are formed, and the terminal electrodes 32a and 32b are connected to each other by a side electrode 39.

The ferrite element 24 is provided with a net-shaped first to third center conductors 27 and 2 on a disc-shaped shield (not shown).
9, a ferrite 30 for microwaves is disposed on the shield part, and the respective center conductors 27 to 29 are electrically insulated from each other on the upper surface of the ferrite 30.
It is structured to be bent and arranged to intersect at every 20 degree angle. Also, the external connection part 2 of each of the center conductors 27 to 29
Reference numerals 7a to 29a are bent and formed stepwise, and project outward.

The matching capacitor substrate 23 has an insertion hole 31a formed at the center thereof, and the first hole is formed at the periphery of the insertion hole 31a.
To third capacitor electrodes (matching capacitors) C1 to C3 are formed by thick film printing, and a terminating resistor film (terminator) R is connected to the third capacitor electrode C3 by thick film printing. .

The ferrite element 24 is inserted into the insertion hole 31a of the capacitor substrate 23, so that the lower surface of the ferrite 30 is connected to the bottom wall of the lower yoke 22 via the shields of the central conductors 27 to 29. 22a.

External connection portions 27a to 29a of the center conductors 27 to 29 are connected to the capacitor electrodes C1 to C3.
And the first and second center conductors 2
7, 27a, connection portions 27a, 28a, and tip portions 27b, 28
b denotes input / output terminal electrodes 32a, 32 of the terminal board 21.
b.

As shown in FIG. 1, the capacitor substrate 23 is formed by laminating thin substrate substrates which characterize this embodiment.

The capacitor substrate 23 is formed by laminating a bonding prepreg thin substrate 35 between the first and second thin substrate 33, 34, and thermocompression-bonding them. The substrates 33 to 35 are made of a material such as dielectric, ceramic, glass epoxy, BT resin, or glass Teflon.

The capacitor electrodes C1 to C3 and the terminating resistor film R are formed on the upper surface of the second dielectric substrate 34, and the ground electrode 40 is patterned on the entire lower surface of the substrate 34. . Ground electrodes 40 and 41 are formed on the lower surface of the thin substrate 33 in a pattern, respectively. The electrodes 40 and 41 face each other with the thin substrate 33 interposed therebetween.

A microstrip line 42 is pattern-formed on one side of the insertion hole 31a on the upper surface of the first thin plate substrate 33, and a ground electrode 41 is formed on the entire lower surface of the substrate 33. The strip line 42 is a line whose line length is an integral multiple of 1 / 4.lambda.g.
5 and the second dielectric substrate 34 are connected to the terminating resistance film R via through-hole electrodes 43 formed therethrough.

The other end 42 of the strip line 42
b is connected to the ground electrodes 40 and 41 via through-hole electrodes 44 formed through the thin plate substrate 33 and the prepreg substrate 35, thereby forming the matching circuit for widening the band of the present embodiment. ing. Here, the other end 42b side of the strip line 42 may be opened without being connected to the ground.

Next, the operation and effect of this embodiment will be described. According to the isolator 20 of the present embodiment, １ ／ · λ
g is formed on the first thin substrate 33, and the substrate 33 is provided with the prepreg substrate 35 interposed therebetween to form the second capacitor electrodes C1 to C3.
Since the capacitance substrate 23 was formed by laminating the capacitor substrate together with the thin plate substrate 34, I.I. L. The isolation characteristic can be broadened while avoiding the influence on the characteristic, whereby the reflected wave can be surely absorbed and the invasion of the unnecessary wave can be prevented. Incidentally, in the present embodiment, the frequency band can be expanded to about 1.5 to 2 times.

In this embodiment, the isolator 20
Since the thin substrate 33 is built in and integrated with the capacitance substrate 23, the dimensions, volume, and weight of the conventionally used capacitance substrate can be made almost the same, so that the above-described matching circuit is separately mounted. Compared with this, it is possible to reduce the size and weight of parts.

Further, in this embodiment, since it is only necessary to set the line length of the strip line 42 so as to have the above-mentioned electrical length, there is less variation as compared with the case where the matching circuit element is constituted by the above-mentioned lumped constant. A high-precision broadband circuit can be configured. As a result, the electrical adjustment can be simplified or no adjustment can be made, so that the cost can be reduced and the cost of parts can be reduced.

In the above embodiment, three thin substrates 3
Although the case where the capacitance substrate 23 is formed by thermocompression bonding of 3 to 35 has been described as an example, the present invention is, for example, to pattern each electrode on a green sheet and sinter the electrode and the green sheet integrally to form the capacitance substrate 23. May be formed.

Further, in the above embodiment, an isolator in which a terminator is connected to a lumped constant type 3-port circulator has been described as an example. However, the present invention is not limited to this. Of course, the present invention can also be applied to a non-reciprocal circuit device of the type.

[0034]

As described above, according to the non-reciprocal circuit device according to the present invention, a strip line having an electric length of 1 / 4.lambda.g is connected to a terminator connected to one port and a thin plate substrate is connected. Formed, and the thin substrate is laminated inside the matching capacitor substrate constituting the non-reciprocal circuit device, so that it is possible to cope with the miniaturization and weight reduction of parts and to reduce the price while widening the isolation characteristics. Has the effect of contributing to

[Brief description of the drawings]

FIG. 1 is an exploded perspective view showing a capacitance substrate of an isolator according to one embodiment of the present invention.

FIG. 2 is an exploded perspective view of the isolator of the embodiment.

FIG. 3 is a perspective view of the isolator of the embodiment.

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

FIG. 5 is a perspective view of an isolator for explaining a process of establishing the present invention.

FIG. 6 is an exploded perspective view of an isolator for explaining a process of establishing the present invention.

FIG. 7 is a perspective view of an isolator for explaining a process of establishing the present invention.

FIG. 8 is a perspective view of an isolator for explaining a process of establishing the present invention.

FIG. 9 is a diagram showing an operation of the isolator for explaining a process of establishing the present invention.

FIG. 10 is a diagram showing an operation of an isolator for explaining a process of establishing the present invention.

FIG. 11 is a diagram showing the operation of a general isolator.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 20 Isolator (non-reciprocal circuit element) 23 Capacitance board 27-29 Center conductor 30 Ferrite 33-35 Thin board 42 Strip line R Terminating resistance film (terminator)

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) H01P 1/36 H01P 1/383

Claims (1)

(57) [Claims] A plurality of center conductors are arranged in a ferrite to which a DC magnetic field is applied in an electrically insulated state and cross each other, and a matching capacitor is connected to a port of each of the center conductors.
And connect a terminator to any one of the ports,
A non-reciprocal circuit device in which a matching circuit is connected to the terminator so as to widen an isolation characteristic, wherein the matching circuit has an electric length of 1 / 4.lambda.g (.lamda.g is a line wavelength). A double line is used, and the line is formed as a strip line on a thin plate substrate, and the thin plate substrate is laminated inside a matching capacitor substrate constituting the non-reciprocal circuit device. Irreversible circuit element.