JP2001028504A - Circulator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To manufacture a circulator without deteriorating its characteristics, while working accuracy is not set strict, and also to miniaturize the circulator. SOLUTION: This circulator consists of a base plate 1, composed of metal being non-magnetic material, Y branch-shaped dielectric parts 2 provided on the plate 1, pillar-shaped ferrite 3 embedded in the central part of the Y branch parts of the parts 2, a matching part 4 which is provided on the Y branch parts of the parts 2 and matches impedance between the parts 2 and the ferrite 3, and a metallic case 5 which is made of nonmagnetic material, connected to the plate 1 and has groove parts 5a where the parts 2 provided with the ferrite 3 and the part 4 are fitted.

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 used in a microwave band or a millimeter wave band, and particularly to a circulator.

[0002]

2. Description of the Related Art As a general structure of a circulator,
A device constituted by a microstrip line or a waveguide is known. In the microstrip circulator, as shown in FIG. 8, a three-junction microstrip line 102 is formed on one surface of a ferrite substrate 101.
A ground conductor 103 is formed on the other surface of the ferrite substrate 101, and a bonding surface portion 102 of the microstrip line 102 is formed.
structure that resonates the a mode close to the TM ₁₁₀ mode is common (for example, refer to FIG. 5 of JP-A-11-017408 JP). As shown in FIG. 9, the waveguide circulator is a waveguide 1 inside a three-junction type waveguide 104.
The ferrite 105 disposed 04 joining the space of the structure for operating the ferrite 105 as a resonator of the TM ₁₁₀ mode is generally (e.g. JP-A 2-039602
Reference).

In the case of the above-described waveguide circulator, a structure for converting the waveguide into a circuit pattern and connecting the circuit must be provided as an interface of the circulator to another integrated circuit. As a result, there is a problem that the mounting area is increased by the interface.

On the other hand, when a microstrip line is formed on a ferrite substrate as in the microstrip circulator having the above configuration, the effective wavelength is shortened because the dielectric constant of the ferrite substrate is relatively high. As a result, the influence of the dimensional accuracy of the microstrip line formed on the ferrite substrate on the circulator characteristics is particularly large.
It becomes large in the millimeter wave band such as GHz or more, and it is difficult to manufacture the device from the viewpoint of yield.

Therefore, a three-junction microstrip line is formed on a ceramic substrate in which a ferrite disk is embedded, as shown in JP-A-61-288486 and JP-A-11-017408. In addition, a structure in which only the joint surface of the microstrip line is used can be considered.

[0006]

However, Japanese Patent Application Laid-Open No.
Even in a circulator using a strip line as assumed in 288486 or the like, particularly at a high frequency such as 50 GHz, the circulator characteristics greatly change due to the accuracy of the junction surface of the microstrip line and the corresponding embedding position of the ferrite disk. There are still problems. SUMMARY OF THE INVENTION An object of the present invention is to provide a circulator that can be manufactured without deteriorating characteristics even if processing accuracy is not severe and that can be reduced in size, in view of the above-mentioned problems of the related art.

[0007]

In order to achieve the above object, according to the present invention, a dielectric portion is provided throughout the inside of a Y-branch type waveguide, and a dielectric portion is provided at the center of the Y-branch portion of the dielectric portion. This is a circulator with ferrite embedded.

In particular, the circulator of the present invention is embedded in a base plate made of a non-magnetic metal, a Y-branch-shaped dielectric portion provided on the base plate, and a central portion of the Y-branch portion in the dielectric portion. And a metal case made of a non-magnetic material joined to the base plate and having a groove in which the dielectric portion is fitted. In this case, a dielectric waveguide is formed by the dielectric portion, the wall of the groove of the metal case surrounding the dielectric portion, and the portion of the base plate where the dielectric portion is formed.

In the case of a circulator structure using a microstrip line as assumed in the conventional Japanese Patent Application Laid-Open No. 61-288486, at a high frequency such as 50 GHz or more even in the case of a millimeter wave, the junction surface of the microstrip line is made to correspond thereto. The characteristics vary greatly depending on the accuracy with the embedding position of the ferrite disk.

On the other hand, in the case of the structure of the present invention, since the shape of the dielectric portion affects the characteristics of the circulator, the accuracy of the embedding position of the ferrite in the dielectric portion (tolerance between the ferrite and the embedding hole). ) Does not have to be too strict. Also, when fitting the groove portion of the metal case and the dielectric portion, the distance between the wall surface of the groove portion of the metal case forming a part of the waveguide wall of the waveguide and the dielectric portion disposed in the groove portion is also set. Avoid tight tolerances. Therefore, the circulator of the present invention can be manufactured without deteriorating the characteristics without strict processing accuracy, and is easy to manufacture from the viewpoint of yield. Further, in the circulator as described above, since the conversion section for converting to the microstrip line is further provided in the dielectric portion, mounting to a circuit using the microstrip line becomes easy.

It is preferable that the apparatus further comprises a matching section for matching impedance between the ferrite and the dielectric section.

The use of a magnetoplumbite type hexagonal ferrite as the ferrite eliminates the need for an external magnet, thereby facilitating miniaturization.

According to the present invention, there is also provided a conductor layer disposed to face a dielectric substrate, and two rows of via holes for electrically connecting the conductor layers, the via holes being formed at intervals smaller than a cutoff frequency in the arrangement direction. A waveguide section formed by forming a region surrounded by the two rows of via holes thus formed into a Y-branch shape when the dielectric substrate is viewed in a plan view; and Also provided is a circulator having a columnar ferrite embedded in the center of the Y-branch. Also in the case of the present invention, since the shape of the region surrounded by the opposing conductor layer and the two rows of via holes affects the characteristics of the circulator, ferrite is embedded as in the case of a circulator using a strip line. The accuracy of the position does not have to be strict. Further, since the via hole is formed in the dielectric substrate having the conductor layer, the manufacturing is easy from the viewpoint of yield.

[0014]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows a first embodiment of the present invention.
Exploded perspective view showing a circulator according to the embodiment,
FIG. 2 is a longitudinal sectional view of the circulator according to the first embodiment of the present invention, cut along a dielectric portion.

As shown in FIG. 1, the circulator of the present embodiment includes a base plate 1 made of a non-magnetic metal,
Y-branch type dielectric portion 2 provided on base plate 1
And a columnar ferrite 3 buried in the center of the Y-branch of the dielectric portion 2 and a ferrite 3 provided at the Y-branch of the dielectric 2 for impedance matching between the dielectric 2 and the ferrite 3. A matching part 4 and a non-magnetic metal case 5 joined to the base plate 1
And a groove portion 5 in which the dielectric portion 2 provided with the matching portion 4 is fitted.
and a metal case 5 having a. The impedance matching section 4 is a part of the dielectric section 2 and is integrally formed of the same dielectric material as the dielectric section 2.

In the case of this embodiment, the impedance matching section 4
A waveguide is constituted by a dielectric part 2 including the above, a wall of the groove part 5a of the metal case 5 surrounding the dielectric part 2 including the impedance matching part 4, and a part of the base plate 1 where the dielectric part 2 is provided. Have been. Such a structure is described below.
It is called a dielectric waveguide. In the present invention, any structure may be used as long as the structure has a dielectric portion provided inside the entire waveguide, in other words, a structure in which the dielectric portion is surrounded by a nonmagnetic metal wall. Absent.

In the above-described dielectric waveguide, for example, when an alumina ceramic which is a dielectric material having a relative permittivity ε _{r of} about 10 is disposed inside, a normal waveguide in which air is inside is used. In comparison, a waveguide having the same characteristics can be manufactured with a size of about 30%. Therefore, for example, a waveguide having a width of 3.1 mm called “E band (WR-12)” can be made with a width of about 1 mm. Abbreviations for microwave and millimeter wave waveguides are used for respective frequencies, and waveguides in the 60 to 90 GHz band are called E band,
V band, 40 GH for 50 GHz to 75 GHz band
Those in the z to 60 GHz band are called U-bands. Another notation is inch size notation, and since the E band is 1.2 inches, it can also be written as WR-12. Generally, a waveguide is denoted by WR.

Here, a method of manufacturing the circulator of the above embodiment will be briefly described. First, the dielectric part 2 including the impedance matching part 4 is formed on the base plate 1. Next, a hole for inserting the ferrite 3 is formed at the center of the Y branch portion of the dielectric portion 2 including the impedance matching portion 4, and the ferrite 3 is mounted in the hole. Finally, the dielectric portion 2 provided with the ferrite 3 and the matching portion 4 is fitted into the groove 5a of the metal case 5, and the metal case 1 is joined to the base plate 1.

In this embodiment, the ferrite 3 is a hexagonal ferrite and a magnetoplumbite ferrite. According to this ferrite, a magnet is unnecessary because the ferrite itself is magnetized, and as a result, the mounting space can be made compact. Further, if a magnet is mounted on the upper part of the non-magnetic metal case 5, the normal N
It is also possible to use ferrite such as i-Zn or Mn-Mg.

In this embodiment, since the dielectric portion 2 provided with the ferrite 3 and the matching portion 4 is fitted into the groove 5a of the metal case 5, the outer surface of the dielectric portion 2 having the impedance matching portion 4 is fitted. A clearance is required between the metal case 5 and the wall of the groove 5a. In the structure of the dielectric waveguide applied to the present invention, since the shape of the dielectric portion affects the characteristics of the circulator, the above clearance may be a rough dimension of at least about 50 μm. Therefore,
The tolerance between the groove 5a of the metal case 5 and the dielectric portion 2, that is, the processing accuracy of the groove 5a does not have to be too strict. Further, in the ferrite buried portion of the dielectric portion 2, since the shape and height of the buried hole are important as parameters affecting the characteristics, the tolerance between the ferrite and the buried hole (processing accuracy of the ferrite shape) is also very small. You don't have to be strict. As described above, the circulator of the present embodiment is easy to manufacture from the viewpoint of yield.

(Second Embodiment) FIG. 3 shows a second embodiment of the present invention.
Exploded perspective view showing a circulator according to the embodiment,
FIG. 4 is a perspective view showing the circulator of FIG. 3 after assembly, and FIG. 5 is a longitudinal sectional view of the circulator of FIG. 3 after assembly along the dielectric portion.

The circulator of this embodiment is shown in FIGS.
As shown in (1), the structure of the first embodiment is further provided with a converter 6 for converting a microstrip line and a dielectric waveguide. Specifically, the conversion unit 6 forms a microstrip line on the top surface on the tip side of the dielectric unit 2, and continuously forms a conductor pattern on the top surface of the dielectric unit 2 from the microstrip line in the Y direction of the dielectric unit 2. The structure is such that the thickness is gradually increased toward the branch portion and the side surface of the dielectric portion 2 is metallized when the width of the dielectric portion 2 is reached. In the case of this structure, the conductive pattern formed on the upper surface and both side surfaces of the dielectric portion 2 and the portion of the base plate 1 on which the dielectric portion 2 is formed form the wall of the dielectric waveguide. The conversion section 6 can be formed by using a method such as plating or etching.

By adding such a conversion section 6 between the microstrip line and the dielectric waveguide, in addition to the effect of the first embodiment, mounting on a high frequency integrated circuit in which the microstrip line is frequently used is provided. Becomes easier. In this case, a magnet is not required particularly by using a magnetoplumbite-based ferrite, so that it can be mounted on a multi-chip module and downsizing is facilitated.

In this embodiment, as in the first embodiment, there is a clearance between the outer surface of the dielectric 2 having the converter 6 and the wall of the groove 5a of the metal case 5. Even if the dimensional accuracy of the rinse is not strict, the characteristics do not deteriorate, so that the production is easy from the viewpoint of the yield.

(Third Embodiment) FIG. 6 shows a third embodiment of the present invention.
FIG. 7 is a perspective view showing a circulator according to the embodiment of FIG.
FIG. 7 is a sectional view taken along line AA ′ of FIG.

As a circulator of the form shown in FIGS. 6 and 7, for example, a dielectric substrate 1 made of a ceramic material is used.
Outer layer conductors 12 and 13 are formed on both surfaces of the substrate. A large number of via holes 14 are provided between the outer layer conductors 12 and 13 for electrically connecting the outer layer conductors 12 and 13 to each other.
The via holes 14 are formed in two rows at a predetermined interval b and at a predetermined interval c in the extending direction. Furthermore, the rows of via holes 14 are arranged in a Y-branch form.
The predetermined interval c between the via holes 14 is set to an interval smaller than the cutoff frequency, thereby forming an electric wall.

As described above, since the outer conductors 12 and 13 on both surfaces of the dielectric substrate 1 are electrically connected in the row of the via holes 14, the pseudo side walls formed by the row of the via holes 14 and the outer conductors 12 and 13 are formed. A dielectric waveguide having a structure in which the dielectric material is surrounded on all sides by the upper and lower walls is formed.

A columnar ferrite 15 is buried at the center of the Y-branch in the portion that becomes the dielectric waveguide. As the ferrite 15, as in the first embodiment, hexagonal ferrite such as magnetoplumbite ferrite or Ni-Zn or Mn-Mg ferrite can be used.

In addition to a portion between the outer conductors 12 and 13 other than the portion serving as the dielectric waveguide, the outer conductors 12 and 13 are connected to via holes 14 forming pseudo side walls.
May be provided in parallel with the inner layer conductors 17 and 18. Thereby, the pseudo wall formed by the rows of the via holes 14 becomes a fine mesh shape by the connection of the inner layer conductors 17 and 18, so that the effect of blocking the electromagnetic waves in the rows of the via holes 14 can be enhanced.

Further, a portion of the dielectric waveguide except for the Y branch around the ferrite 15 is formed so as to be connected to the via hole 14 and to be parallel to the outer conductors 12 and 13. An inner layer conductor 19 may be provided, and the inner layer conductor 19 may constitute an upper wall of the dielectric waveguide. The inner conductor 19 can be formed in the same layer as the inner conductor 18. In the case of this configuration, a plurality of via holes 16 for electrically connecting the inner layer conductor 19 and the outer layer conductor 12 are provided at intervals smaller than the cutoff frequency in order to block the transmission of electromagnetic waves between the inner layer conductor 19 and the outer layer conductor 12. It is arranged in. In addition, a part of the dielectric at the Y-branch of the part to be the dielectric waveguide forms a matching part 11a for achieving impedance matching between the dielectric at the part to be the dielectric waveguide and the ferrite 15. Make up.

The circulator having the above configuration can be easily manufactured by using a ceramic multilayer substrate manufacturing technique in which green sheets on which pattern printing and holes are formed are laminated and sintered. In addition, since the dielectric waveguide can be freely set by forming a via hole at an arbitrary position in the dielectric substrate 11, the configuration is simple.
A circulator that can be reduced in size can be provided.

[0033]

As described above, in the present invention, since the shape of the dielectric portion affects the characteristics of the circulator by using the dielectric waveguide structure, the position of the ferrite embedded in the dielectric portion is reduced. (The tolerance between the ferrite and the buried hole) need not be so strict. Also,
Also in the fitting portion between the groove of the metal case and the dielectric portion, the tolerance of the distance between the wall surface of the groove of the metal case forming a part of the waveguide wall of the waveguide and the dielectric portion disposed in the groove. Do not have to be strict. Therefore, the circulator of the present invention can be manufactured without deteriorating the characteristics without strict processing accuracy, and is easy to manufacture from the viewpoint of yield.

Further, by providing a conversion section for conversion to a microstrip line in the dielectric section, a mounting space can be reduced in mounting on a circuit using the microstrip line.

Also, a dielectric waveguide structure can be realized by a simple structure in which a via hole is formed in a dielectric substrate having a conductor layer, and a circulator using the same can be manufactured easily with a high yield. Become.

[Brief description of the drawings]

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

FIG. 2 is a longitudinal sectional view of the circulator of FIG. 1 after being assembled, which is cut along a dielectric portion.

FIG. 3 is an exploded perspective view showing a circulator according to a second embodiment of the present invention.

FIG. 4 is a perspective view showing the circulator of FIG. 3 after being assembled.

5 is a longitudinal sectional view of the circulator of FIG. 3 after being assembled, which is cut along a dielectric portion.

FIG. 6 is a perspective view showing a circulator according to a third embodiment of the present invention.

FIG. 7 is a sectional view taken along line A-A ′ of FIG. 6;

FIG. 8 is a perspective view showing a conventional circulator constituted by a microstrip line.

FIG. 9 is a perspective view showing a conventional circulator composed of a waveguide.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Base plate 2 Dielectric part 3 Ferrite 4 Impedance matching part 5 Metal case 5a Groove part 6 Conversion part between microstrip line and dielectric waveguide 11 Dielectric substrate 12, 13 Outer layer conductor 14, 16 Via hole 15 Ferrite 17, 18 , 19 Inner layer conductor

Claims (12)

[Claims] 1. A circulator comprising: a dielectric portion provided in the entire inside of a Y-branch type waveguide; and a columnar ferrite embedded in the center of the Y-branch portion of the dielectric portion. 2. A base plate made of a non-magnetic metal, a Y-branch-type dielectric portion provided on the base plate, and a columnar ferrite embedded in a center of the Y-branch portion in the dielectric portion. A circulator comprising: a metal case joined to the base plate; and a nonmagnetic metal case having a groove in which the dielectric portion is fitted. 3. A dielectric waveguide is constituted by the dielectric portion, a wall of a groove of the metal case surrounding the dielectric portion, and a portion of the base plate on which the dielectric portion is formed. A circulator according to claim 2. 4. The circulator according to claim 1, further comprising a conversion section for converting the microstrip line into the dielectric section. 5. The circulator according to claim 1, further comprising a matching section for matching impedance between said ferrite and said dielectric section. 6. The circulator according to claim 1, wherein the ferrite is a hexagonal ferrite and is a magnetoplumbite type. 7. The circulator according to claim 1, wherein said dielectric portion is made of a ceramic material. 8. The circulator according to claim 1, which is used in a millimeter wave band. 9. A conductor layer disposed to face a dielectric substrate, and two rows of via holes for electrically connecting the conductor layers, the via holes being formed at intervals smaller than a cutoff frequency in the arrangement direction. A waveguide section formed by forming a region surrounded by a row of via holes in a Y-branch shape when the dielectric substrate is viewed in a plan view; and a Y-branch section of the waveguide section. And a columnar ferrite embedded in the center of the circulator. 10. The apparatus according to claim 9, further comprising a matching section for matching impedance between said ferrite and said waveguide section.
The circulator according to claim 1. 11. The circulator according to claim 9, wherein the ferrite is a hexagonal ferrite and is a magnetoplumbite type. 12. The circulator according to claim 9, wherein said dielectric substrate is made of a ceramic material.