JP2002026616A - Vhf band use irreversible circuit element and private wireless communication unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a small-sized VHF band use irreversible circuit element with an excellent electric characteristic. SOLUTION: The VHF band use irreversible circuit element is characteristically provided with three sets of strip lines 12 that are electrically isolated from each other and overlapped crossing at a prescribed angular interval, a ferrite board 11 on one major side of which the strip lines 12 are closely arranged, a ground disk 22 that is placed opposite to the strip lines 12 via the ferrite board 11, a magnet 18 that magnetizes the ferrite board 11, three sets of matching capacitors respectively connected to the strip lines 12, and yoke cases 16, 19. Parallel plate capacitors 14 of a single layer structure accounts for 50% of the total sum of the capacitances of the three sets of matching capacitors or over.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a non-reciprocal circuit device such as an isolator or a circulator that uses a ferrite to give directionality to signal transmission in the VHF band. Also,
The present invention relates to a wireless communication device using them.

[0002]

2. Description of the Related Art Isolators, which are nonreciprocal circuit elements,
It is arranged between a power amplifier and an antenna in a transmission circuit of a communication device, and is used for the purpose of preventing backflow of an unnecessary signal to the power amplifier, stabilizing the impedance on the load side of the power amplifier, and the like. The circulator can also be used in the same manner as the above-mentioned isolator by terminating one of its input / output terminals with a resistor.

FIG. 9 is an exploded perspective view of a circulator 1 according to the prior art. The conventional circulator 1 includes a disk-shaped ferrite plate 2, a magnet 3 arranged to face the ferrite plate 2, and yoke cases 4 a and 4 b including these and constituting a magnetic circuit. Although the yoke cases 4a and 4b are fitted and integrated, FIG. 5 shows a state where the yoke cases are disassembled.

Around the ferrite plate 2, there are arranged three sets of strip lines 5a, 5b and 5c which are electrically insulated from each other and cross and overlap at an angle of about 120 degrees. Strip lines 5a, 5b and 5c
Capacitors 8a, 8b and 8 each having one end arranged in parallel with input / output terminals 7a, 7b and 7c as shown in the figure.
c. Here, each symbol in the figure is associated with the same alphabet.

The other ends of the strip lines 5a, 5b and 5c are connected to the ground disk 6 on the lower surface of the ferrite plate 2 (the surface closer to the yoke 4b).

The ground disk 6 is connected to a ground terminal (not shown in FIG. 9) for external connection together with the ground electrode and the yoke case 4b in other elements. The yoke cases 4a and 4b are electrically connected by fitting or soldering as necessary. Although the configuration of the circulator has been described with reference to FIG. 9, if a resistor is connected to one of the input / output terminals 7a, 7b or 7c and terminated, the circulator can be configured as an isolator.

An isolator having the above configuration,
Non-reciprocal circuit devices such as circulators increase in device size as the frequency handled decreases. This is mainly because the operating frequency of the non-reciprocal circuit element is mainly determined by the size of the ferrite plate 2 and the matching capacitors 8a and 8b shown in FIG.
And 8c.

The size of the ferrite plate 2 and the capacitance of the matching capacitor have a complementary relationship. If one is reduced, the frequency increases unless the other is increased. Naturally, there is an optimal combination of ferrite diameter and capacitor value that minimizes the signal loss.
In the actual design of the non-reciprocal circuit device, it is necessary to consider the size of the entire non-reciprocal circuit device required for practical use. , And a design that prioritizes miniaturization is made.

By the way, in the design where priority is given to miniaturization of the non-reciprocal circuit device, it is necessary to reduce the size of the ferrite plate and increase the capacitance value of the matching capacitor. In particular, VHF
In the non-reciprocal circuit device in the band, the required capacitance value is considerably larger than the capacitance value required in the non-reciprocal circuit device in the UHF band used for mobile phones and the like.

Conventionally, in order to secure the large capacity value, V
In a non-reciprocal circuit device in the HF band, a multilayer chip capacitor using a multilayer structure has been used as a matching capacitor.

[0011]

However, when the matching capacitor is constituted by a multilayer chip capacitor having a multilayer structure, there is a problem that the electrical characteristics, particularly the signal loss, are deteriorated. When the size of the plate was reduced and the capacitance value of the matching capacitor was increased, the value became larger.

For this reason, in the conventional non-reciprocal circuit device in the VHF band, the ferrite diameter must be designed to a certain degree or more in order to obtain satisfactory electrical characteristics. In this case, miniaturization was difficult, for example, the element size became 20 mm square or more. In addition, it has been difficult to reduce the size of a self-propelled wireless communication device using the VHF band.

An object of the present invention is to provide a non-reciprocal circuit device for a VHF band which is small and has excellent electrical characteristics in order to solve the conventional problems. It is another object of the present invention to provide a small, high-performance wireless communication device using these non-reciprocal circuit devices.

[0014]

In order to achieve the above object, the first invention (corresponding to claim 1) is electrically insulated from each other and overlapped so as to intersect at a predetermined angle. Three sets of strip lines, a ferrite plate that arranges the three sets of strip lines close to one main surface, a ground electrode that is arranged to face the three sets of strip lines via the ferrite plate, A magnet for magnetizing the ferrite, three sets of matching capacitors respectively connected to the three sets of striplines, and the stripline, the ferrite plate, the ground electrode, the magnet, and the three sets of A case that includes a matching capacitor and forms a part of a magnetic circuit,
The non-reciprocal circuit device for the VHF band is characterized in that at least 50% of the sum of the capacitance values of the three sets of matching capacitors is formed by a single-layer parallel plate capacitor.

Further, the second invention (corresponding to claim 2)
The present invention is characterized in that at least 50% of the capacitance value of each of the three sets of matching capacitors is formed by a single-layer parallel plate capacitor.

As a result, the signal transmission loss can be reduced as compared with the case where the necessary capacitance value of the matching capacitor is mainly borne by using a multilayer chip capacitor having a multilayer structure. Therefore, the electrical characteristics can be maintained even if the size of the ferrite plate is made smaller than that of the conventional nonreciprocal circuit device and the capacitance value of the matching capacitor is increased. It is preferable that 50% or more of the required capacitance value of each of the three sets of matching capacitors is formed by a single-layer parallel plate capacitor. Since the matching capacitor connected to the strip line is less affected by the signal transmission loss characteristics, the ratio of the single-layer parallel plate capacitor can be reduced. Further, the thickness of the dielectric layer of the single-layer parallel plate capacitor is 15
The thickness is preferably 0 μm or less, so that a parallel plate capacitor having a sufficient capacitance can be made small even in a single-layer structure, and the element can be downsized.

Further, the third invention (corresponding to claim 3)
The parallel plate capacitor having a single-layer structure, a counter electrode disposed to sandwich the dielectric layer from both main surfaces, a reinforcing member provided on at least one main surface of the counter electrode, An external electrode provided on a surface of a reinforcing member, wherein the counter electrode and the external electrode are electrically connected via a via hole.

Thus, sufficient strength can be ensured even when the thickness of the dielectric layer of the single-layer parallel plate capacitor is reduced.

The fourth invention (corresponding to claim 4)
Are three sets of strip lines that are electrically insulated from each other and overlap each other at a predetermined angle, a ferrite plate that arranges the three sets of strip lines close to one main surface, A ground electrode disposed to face the three sets of strip lines via a plate; a magnet for magnetizing the ferrite; and three sets of matching elements connected to the three sets of strip lines, respectively. A case that includes a capacitor and the strip line, the ferrite plate, the ground electrode, the magnet, and the three sets of matching capacitors and forms a part of a magnetic circuit; and at least a part of the matching capacitors. Has a portion that overlaps with the ferrite plate in the direction of the lamination plane of the ferrite plate and the strip line. It is a non-reciprocal circuit element for VHF band according to claim.

Thus, the element size can be reduced as compared with the conventional configuration in which the matching capacitors are arranged around the ferrite plate. Further, the present invention relates to the above-described first aspect.
By combining with the third to third aspects, a small non-reciprocal circuit device for VHF band having excellent electric characteristics can be formed.

Further, a fifth aspect of the present invention (corresponding to claim 5)
Comprises a structural material provided between the ground electrode and the case, on the side adjacent to the ground electrode, wherein the structural material is projected in a stacking direction of the ferrite plate and the strip line. The present invention is characterized in that a notch is provided in a portion overlapping the ferrite plate, and at least a part of the matching capacitor is arranged in the notch.

The sixth invention (corresponding to claim 6)
Further comprises a ground terminal for external connection provided on the side of the case adjacent to the ground electrode, wherein the structural material is a conductor, and the case on the side adjacent to the ground electrode and the ground electrode. And the present invention is electrically connected.

This eliminates the need for preparing a special electrode for connecting the ground electrode to an external ground terminal,
The configuration of the element can be simplified.

The seventh invention (corresponding to claim 7)
The present invention is characterized in that an area of a portion of the ground electrode facing the ferrite plate is smaller than an area of the ferrite plate.

Thus, even if the electrode surface to which the strip line of the matching capacitor is connected is below the ground electrode surface, each strip line bent along the side surface from the top surface of the ferrite plate is connected to the ground electrode. Short circuit can be prevented.

The eighth invention (corresponding to claim 8)
The present invention is characterized in that the present invention further comprises a predetermined dielectric layer provided between the ferrite plate and the ground electrode.

Thus, the internal magnetic field distribution is made uniform by the effect of separating the ferrite plate from the yoke case, thereby improving the signal transmission loss. At the same time, the operating frequency can be increased without increasing the capacitance value of the matching capacitor. Can be lowered.

The ninth invention (corresponding to claim 9)
The present invention is further characterized by further comprising a second ferrite plate facing the one main surface of the ferrite plate and provided so as to sandwich the three sets of strip lines together with the ferrite plate. is there.

Thus, the magnetic field distribution in the ferrite plate is made uniform, so that the signal transmission loss can be improved.

According to a tenth aspect of the present invention (corresponding to claim 10), one of the three sets of strip lines is terminated by a resistor having a predetermined resistance value to be used as an isolator. The present invention is characterized by the features described above.

As a result, V is small and has excellent electrical characteristics.
An HF band isolator can be obtained.

The eleventh invention (corresponding to claim 11) is a self-contained radio communication device characterized by using the VHF band nonreciprocal circuit device of the first to tenth inventions.

As a result, it is possible to provide a small-sized wireless communication device which has been difficult to miniaturize.

[0034]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be specifically described below with reference to the drawings.

(Embodiment 1) FIG. 1 is an exploded perspective view of a non-reciprocal circuit device 10 according to Embodiment 1 of the present invention. As shown in the figure, the non-reciprocal circuit device 10 according to the first embodiment of the present invention
1, three sets of strip lines 12 which are insulated from each other and intersect at approximately 120 degrees and overlap each other are wound around a disk-shaped ferrite plate 11.

Here, the strip line 1 will be described with reference to FIG.
2 and the ferrite plate 11 will be described in detail. FIG.
As shown in FIG. 2, an insulating layer 21a is provided between the strip lines 12a and 12b, and the strip lines 12b and 12c
The insulating layers 21b are respectively arranged between them. One end of each of the three strip lines is similar to that described with reference to FIG.
It is connected to the grounding disk 22 arranged on the lower surface of the ferrite plate. In FIG. 1, the insulating layer between the strip lines is omitted, and the ground disk is not shown because it is the lower surface of the ferrite plate 11. Also, the insulating layers 21a, 21
The description of b and the grounding disk 22 is the same in the following similar exploded perspective views.

In FIG. 1, three sets of strip lines 1
The other end of 2 is connected to three single-layer parallel plate capacitors 14 arranged on the arrangement plate 13. Further, a grounding disk on a surface (hereinafter, referred to as a lower surface) near the lower yoke case 16 of the ferrite plate is also connected to a predetermined position on the arrangement plate 13. The lower surface of the arrangement plate 13 connected to the lower yoke case 16 is a ground electrode on the entire surface, and is electrically connected to the ground electrode pattern 20a on the upper surface to which the single-layer parallel plate capacitor 14 and the ground disk are connected and through holes. Connected. The three multilayer chip capacitors 15 each having a multilayer structure are connected to the land-shaped electrodes 20b provided on the arrangement plate 13 and the ground electrode patterns so as to be bridged.

The three input / output terminals 17 are connected to a land-shaped electrode 20b to which one electrode of the multilayer chip capacitor 15 of the multilayer structure is connected. Above, they are connected to the other ends of the three sets of strip lines 12.

The lower yoke case 16 is provided with a ground terminal 30 for external connection. A magnet 18 for applying a magnetic field is arranged on the upper surface of the ferrite plate 11, and an upper yoke case 19 is fitted to the lower yoke case 16 to form a magnetic circuit.

As an example of the nonreciprocal circuit device according to the present embodiment having the above-described configuration, a 20 mm square circulator operating in the 260 MHz band and a 15 mm
A circulator of mm square size was produced. In the case of a 20 mm square size, where the diameter of the ferrite plate 11 is 10 mm, the required capacitance value of the matching capacitor is 40 p.
F. For 15mm square size, ferrite plate 1
When the diameter of 1 was 7.5 mm, the required capacitance value of the matching capacitor was 50 pF.

FIG. 3 shows the results of the measurement of the passing loss of the circulators of the respective sizes with respect to each of the matching capacitors by changing the capacitance value ratio of the single-layer parallel plate capacitor and the multilayer chip capacitor. showed that. In the figure, 0% of a single-layer parallel plate capacitor is a case of only a multilayer chip capacitor of a multilayer structure, and 100% is a case of only a single-layer parallel plate capacitor.

FIG. 3 shows that when the capacitance ratio of the single-layer parallel plate capacitor is increased, the passage loss is greatly improved when the ratio is about 50%.

From this, it can be understood that the signal loss can be effectively reduced by configuring the parallel plate capacitor having a single-layer structure at 50% or more of the required capacitance value. Further, it can be seen that even when the size of the circulator is made smaller than that of the conventional case and the size of the ferrite plate is made smaller, the electrical characteristics can be maintained by using the configuration of the present invention.

In order to increase the capacitance of a single-layer parallel plate capacitor, (1) increase the area, (2) reduce the thickness of the dielectric layer between the opposing electrodes, and (3) reduce the dielectric constant. A possible measure is to increase the dielectric constant of the body. However, if the thickness of the dielectric layer is 150 μm, even if a parallel plate capacitor with a 100% single-layer structure is used, only a conventional multilayer chip capacitor with a multilayer structure is used. A non-reciprocal circuit device for the VHF band can be configured with the same device size as in the case of the above. Therefore, by setting the thickness of the dielectric layer of the single-layer parallel plate capacitor to 150 μm or less, a small non-reciprocal circuit device for the VHF band having excellent electric characteristics can be easily formed.

The single-layer parallel plate capacitor 14
When the thickness of the dielectric layer is reduced, reliability in terms of strength becomes a problem.
4, a reinforcing member is disposed on at least one of the upper and lower opposing electrodes, an external electrode is provided on the outermost surface of the reinforcing member, and a sufficient strength is secured by connecting the opposing electrode and the external electrode via holes. be able to. At this time, it is preferable to make a plurality of via holes for connecting the counter electrode and the external electrode.

In this embodiment, the matching capacitors have been described as having a capacitance of 50% or more obtained by the parallel plate capacitor 14. However, the capacitance of each of the three sets of matching capacitors has been described. While maintaining at least 50% of the sum of the values by the parallel plate capacitor, the ratio of the parallel plate capacitor 14 used according to the capacitance value in each matching capacitor may be made different. Since the length can be changed for each strip line, there is an effect that a degree of freedom is given to the design.

(Embodiment 2) FIG. 4 is an exploded perspective view of a non-reciprocal circuit device 40 according to Embodiment 2 of the present invention. In the figure, the same or corresponding parts as those in FIG. 1 are denoted by the same reference numerals, and detailed description thereof will be omitted. Reference numeral 41 denotes a grounding table corresponding to the structural material of the present invention. Further, as shown in the drawing, in the nonreciprocal circuit device 40 according to the second embodiment of the present invention, the configuration of the disc-shaped ferrite 11 and the strip line 12 is the same as that of the first embodiment.

In FIG. 4, the grounding disk on the lower surface of the ferrite plate 12 is raised from the upper surface of the lower yoke case 16 by a grounding table 41 which is a conductor, and a space formed thereby is used as a matching capacitor. The three sets of the single-layer parallel plate capacitors 14 are arranged on the lower yoke case 16 such that a part thereof overlaps the ferrite plate 11 at an overlapping position 42 when the upper and lower surfaces of the element are projected. The sides of the three sets of strip lines 12 that are not connected to the ground disk are connected to the three single-layer parallel plate capacitors 14 disposed on the lower yoke case 16. The three input / output terminals 17 are connected to three sets of strip lines 1 on the single-layer parallel plate capacitor 14.
2 is connected. The ground disk on the lower surface of the ferrite plate is electrically connected to the lower yoke case 16 provided with the ground terminal 30 for external connection via the ground table 14. A magnet 18 for applying a magnetic field is provided on the upper surface of the ferrite plate 11.
Are arranged, and the upper yoke case 19 is fitted with the lower yoke case to form a magnetic circuit.

Embodiment 2 having the above configuration
In this configuration, the capacitance of the parallel plate capacitor 14 having a single-layer structure is used for all the capacitance values required for the matching capacitor. Also, since a part of the single-layer parallel plate capacitor is arranged so as to overlap the ferrite plate 12 at the overlapping portion 42 in the projection of the ferrite plate 12 and the strip line 12 in the laminating direction, the ferrite plate Even if the diameter was 7.5 mm, a circulator operating in the 260 MHz band could be constituted by 10 mm square. Passage loss of the fabricated circulator is 0.5d
B, the capacitance ratio of the parallel-plate capacitor having a single-layer structure with a total size of 15 mm square and 100 mm in Embodiment 1 is 100
% Circulator.

Thus, it can be seen that by using the configuration of the present invention, a non-reciprocal circuit device having a small size and excellent electrical characteristics can be easily configured.

The method of raising the grounding disk below the ferrite plate, realized by the present embodiment, is as follows.
The configuration is not limited to the example shown in FIG. 4, and for example, a grounded plate 51 with legs as shown in FIG. 5 may be used.
At this time, it is preferable to provide an insulating layer on the lower surface of the ground plate 51 so as to face the single-layer parallel plate capacitor, since a short circuit with the upper surface electrode of the single-layer parallel plate capacitor can be prevented.

Further, as shown in FIG.
In the configuration shown in FIG. 6, the relationship between the ferrite plate 11 and the grounding disk 22 is as shown in FIG.
6B, the area of the grounding disk 61 is smaller than the area of the ferrite plate 11 as in the configuration shown in FIG. Is preferred. This is because, in the configuration of the second embodiment, the connection position of the three sets of strip lines and the three sets of capacitors is located below the position of the grounding disk, and therefore, FIG.
This is to prevent the strip line 12 from coming into contact with the ground disk 22 in the region 60 surrounded by the dotted line in the middle. As shown in FIG. 6C, it is apparent that the same effect can be obtained by using a grounding disk 62 in which a portion corresponding to the region 60 is cut away from the conventional grounding disk.

In the configuration of the second embodiment,
Although the description has been made on the assumption that a single-layer parallel plate capacitor is used, a conventional multilayer chip capacitor may be mounted as long as the overall size is simply reduced.

(Embodiment 3) The basic configuration of a nonreciprocal circuit device according to Embodiment 3 of the present invention is the same as that of Embodiment 2 described with reference to FIG. Detailed description is omitted. The difference from the fourth embodiment is the configuration of the ferrite plate 11 and the strip line 12, which will be described with reference to FIG.

The present embodiment is different from the conventional configuration in that a dielectric layer 71 is disposed between the ferrite plate 11 and the ground disk 22.

As an example of the non-reciprocal circuit device according to the present embodiment having such a configuration, Table 1 shows a circulator of 260 MHz band constituted by 10 mm square.
Table 1 shows the relationship between the required capacitor capacitance value for the thickness of each type of dielectric layer and the obtained circulator passing loss. Further, as a comparative example, data by the circulator according to the second embodiment of the present invention having no dielectric layer 71 is also shown. The ferrite plate used had a diameter of 7.5 mm and a thickness of 0.7 mm.

[0057]

[Table 1]

From Table 1, it can be seen that the magnetic field distribution inside the ferrite plate is made uniform by using the configuration of the present embodiment.
It can be seen that the passage loss has been improved. Further, the required capacitance value of the capacitor is also reduced. Further, it can be seen that even if the thickness of the dielectric layer 71 is increased to a certain degree or more, the above-mentioned improvement effect is reduced, so that it is not effective.

Further, since the ferrite plate 11 is separated from the lower yoke case 16, uniformity of the magnetic field distribution inside the ferrite can be measured. On the other hand, the strength required for the magnet is further increased. Is required, which is not preferable in configuring the element. Considering these, it can be said that it is effective to set the thickness of the dielectric layer to about 10 to 60% of the thickness of the ferrite plate.

(Embodiment 4) FIG. 8 is an exploded perspective view of a non-reciprocal circuit device 80 according to Embodiment 4 of the present invention. The basic configuration is the same as the example (2) shown in Table 1 of the third embodiment, but in the fourth embodiment, the second ferrite plate 8
1 is disposed opposite to the ferrite plate 11 with the strip line 12 interposed therebetween.

The circulator, which is a non-reciprocal circuit device according to the fourth embodiment having such a configuration, has a pass loss of 0.35 dB, which is significantly larger than that of the third embodiment shown in Table 1 (2). It can be seen that the electric characteristics have been improved. This is because the magnetic field distribution in the ferrite plate 11 is made uniform by the second ferrite plate 81.

Although the embodiments of the present invention have been described using a 260-MHz band circulator mainly used for local disaster prevention radio, etc., the present invention is not limited to this. By terminating one of the three sets of striplines with a resistor having a predetermined resistance, the stripline can be used as an isolator.

Further, as far as the concept of the present invention is concerned, 150
A non-reciprocal circuit device having a small size and excellent electrical characteristics can be configured even in a frequency band of a self-operated radio such as a MHz band and a 60 MHz band. The name of the present invention is a non-reciprocal circuit device for the VHF band.
Although it is effective for the band, a certain effect can be expected even when applied to a lower frequency band of the UHF band such as the 400 MHz band.

It is apparent that a small and high-performance self-contained wireless communication device can be formed by using the VHF band non-reciprocal circuit device as described above to constitute the self-contained wireless communication device. is there.

[0065]

As is apparent from the above description, according to the present invention, it is possible to provide a non-reciprocal circuit device for a VHF band having a small size and excellent electric characteristics. Further, a small and high-performance self-service wireless communication device can be provided by using these non-reciprocal circuit devices.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view of a non-reciprocal circuit device according to Embodiment 1 of the present invention.

FIG. 2 is a detailed view around a ferrite plate of the nonreciprocal circuit device according to the first embodiment of the present invention.

FIG. 3 is a comparison diagram of electrical characteristics of the non-reciprocal circuit device according to Embodiment 1 of the present invention.

FIG. 4 is an exploded perspective view of a non-reciprocal circuit device according to Embodiment 2 of the present invention.

FIG. 5 is an exploded perspective view of the non-reciprocal circuit device according to the present invention.

FIG. 6 is a configuration diagram of a grounding disk.

FIG. 7 is a detailed view around a ferrite plate of a non-reciprocal circuit device according to a third embodiment of the present invention.

FIG. 8 is an exploded perspective view of a non-reciprocal circuit device according to Embodiment 4 of the present invention.

FIG. 9 is an exploded perspective view showing an example of a conventional non-reciprocal circuit device.

[Explanation of symbols]

1, 10, 40, 50, 80 Circulator 2, 11 Ferrite plate 3, 18 Magnet 4a, 19 Upper yoke case 4b, 16 Lower yoke case 6, 22, 61, 62 Grounding disk 5a, 5b, 5c, 12, 12a , 12b, 12c Strip line 13 Arrangement plate 14 Single-layer parallel plate capacitor 15 Multi-layer laminated chip capacitor 17 I / O terminal 20a Ground electrode pattern 20b Land-like electrode 21a, 21b Insulating layer 30 Ground terminal 41 Ground contact 51 Ground plate 71 Dielectric layer 81 Second ferrite plate

Claims (11)

[Claims] 1. A ferrite plate which is electrically insulated from each other and overlapped so as to intersect at a predetermined angle, and a ferrite plate which arranges the three sets of striplines close to one main surface. A ground electrode arranged to face the three sets of strip lines via the ferrite plate; a magnet for magnetizing the ferrite; and three sets respectively connected to the three sets of strip lines And a case that includes the strip line, the ferrite plate, the ground electrode, the magnet, and the three sets of matching capacitors and forms a part of a magnetic circuit, and the three sets of matching capacitors. 50% or more of the sum of the capacitance values of the individual capacitors is formed by a single-layer parallel plate capacitor. Non-reversible circuit element for the F band. 2. The VHF band according to claim 1, wherein 50% or more of the capacitance value of each of the three sets of matching capacitors is formed by a single-layer parallel plate capacitor. Non-reciprocal circuit element. 3. A parallel plate capacitor having a single-layer structure, comprising: a counter electrode disposed so as to sandwich the dielectric layer from both main surfaces; and a reinforcing member provided on at least one main surface of the counter electrode. And an external electrode provided on a surface of the reinforcing member, wherein the counter electrode and the external electrode are electrically connected via a via hole. Non-reciprocal circuit device for VHF band. 4. A set of three strip lines which are electrically insulated from each other and overlap each other so as to intersect at a predetermined angle, and a ferrite plate which arranges the three sets of strip lines close to one main surface. A ground electrode arranged to face the three sets of strip lines via the ferrite plate; a magnet for magnetizing the ferrite; and three sets respectively connected to the three sets of strip lines And a case that includes the strip line, the ferrite plate, the ground electrode, the magnet, and the three sets of matching capacitors, and forms a part of a magnetic circuit. At least a portion of the ferrite plate and the strip line overlap with the ferrite plate when projected in the direction of the lamination surface. A non-reciprocal circuit device for a VHF band, characterized in that the device has a portion. 5. A structural material provided between the ground electrode and a side of the case adjacent to the ground electrode, wherein the structural material is arranged in a direction in which the ferrite plate and the strip line are stacked. 5. The VH according to claim 4, wherein in the projection of (c), a notch is provided in a portion overlapping the ferrite plate, and at least a part of the matching capacitor is arranged in the notch.
Non-reciprocal circuit element for F band. 6. A ground terminal for external connection provided on a side of the case adjacent to the ground electrode, wherein the structural material is a conductor, and is adjacent to the ground electrode and the ground electrode. The VHF band non-reciprocal circuit device according to claim 4, wherein the case is electrically connected to the case. 7. The non-reciprocal circuit device for a VHF band according to claim 6, wherein an area of a portion of the ground electrode facing the ferrite plate is smaller than an area of the ferrite plate. 8. The non-reciprocal circuit device for a VHF band according to claim 1, further comprising a predetermined dielectric layer provided between said ferrite plate and said ground electrode. 9. The semiconductor device according to claim 1, further comprising a second ferrite plate facing said one main surface of said ferrite plate and provided so as to sandwich said three sets of strip lines together with said ferrite plate. Item 5. The non-reciprocal circuit device for VHF band according to Item 1 or 4. 10. The method according to claim 10, wherein:
The nonreciprocal circuit device for a VHF band according to claim 1 or 4, wherein the set is terminated by a resistor having a predetermined resistance value to be used as an isolator. 11. A self-contained wireless communication device using the non-reciprocal circuit device for VHF band according to claim 1.