JPH0735443Y2 - Waveguide type non-reciprocal circuit device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a waveguide type nonreciprocal circuit device (isolator, circulator, etc.).

[Conventional technology]

Conventionally, in a waveguide-type nonreciprocal circuit device, a microwave ferrite is inserted into a waveguide housing integrally formed from a ferrite insertion hole provided in the waveguide housing, and a metal that closes the ferrite insertion hole. Some have a structure that they are fixed by pressing them with a plate (utility model publication No. 8246 published in 1981).

FIG. 7 is a front view showing an example of one three-aperture circulator of a conventional waveguide type nonreciprocal circuit device of this type, and FIG. 8 is a sectional view taken along the line BB 'shown in FIG.

In the figure, 1 is a waveguide housing, 2 is a microwave ferrite, 3 is a ferrite insertion hole provided in the waveguide housing 1, 4 is a metal plate that closes the ferrite insertion hole 3, 5 is a holding ring, and 6
Is a magnet, 7 is a yoke, and 8 is a yoke mounting screw.

The microwave ferrite 2 is inserted into the integrally formed waveguide housing 1 through the ferrite insertion hole 3, and the microwave ferrite 2 is pressed by the metal plate 4 that closes the ferrite insertion hole 3, and the metal plate 4 is pressed by a ring. It is fixed by pressing a yoke 7 fixed to the waveguide housing 1 with a yoke mounting screw 8 at the tip end via 5.

The yoke 7 constitutes a magnetic circuit for applying a magnetic field to the microwave ferrite 2 together with the magnet 6.

[Problems to be solved by the device]

In the conventional circuit element having the above structure, contact between the peripheral side surface of the metal plate 4 that closes the ferrite insertion hole 3 and the side surface of the ferrite insertion hole 3 is not sufficiently maintained, the contact resistance is large, and the microwave loss is large. Become. Further, since external noise easily enters from the contact portion, it adversely affects the microwave signal processing system using the circuit element.

When used in a high-power microwave system, microwave discharge is likely to occur at the contact portion, which adversely affects the microwave oscillation system and the microwave signal processing system.

Since the microwave ferrite 2 is fixed by pressing the metal plate 4 through the pressing ring 5 with the yoke 7, the position of the yoke mounting screw 8 is set to the yoke 7 in order to make this fixation firm.
However, it is disadvantageous in terms of cost.

The present invention has been made to solve the above problems,
An object of the present invention is to provide a structure in which a peripheral side surface of a metal plate that closes the ferrite insertion hole and a side surface of the ferrite insertion hole are in close contact with each other and a yoke can be simply attached to the waveguide housing.

[Means for Solving the Problems]

In order to achieve the above-mentioned object, the waveguide type nonreciprocal circuit device of the present invention has a ferrite insertion hole provided in an integrally formed waveguide housing, and a metal plate closing the insertion hole is press-fitted to fix the ferrite. In the waveguide type nonreciprocal circuit element in which at least one of the side surface of the metal plate and the side surface of the ferrite insertion hole is formed in an uneven shape, the concave shape is formed between the metal plate and the ferrite insertion hole. It is characterized in that the opening size of the gap formed is smaller than the wavelength of the microwave used.

〔Example〕

FIG. 1 is a front view showing an embodiment of the present invention, and FIG. 2 is a first view.
FIG. 6 is a cross-sectional view taken along the line AA ′ shown in the drawing.

In the three-hole circulator, 1,2,3,6,7 indicate the same or corresponding portions as those in FIG. 7 and FIG. 8, 4a is a metal plate whose peripheral side surface is formed in an uneven shape, and 8a is a yoke. The mounting screw 9 is a dielectric plate.

3, 4 and 5 are perspective views showing examples of the metal plate 4a.

FIG. 3 shows an arrangement in which convex portions are arranged vertically in the periphery, FIG. 4 shows an arrangement in which convex portions are arranged in parallel in the periphery, and FIG. 5 shows an arrangement of a large number of small conical protrusions.

When the side surface is shaped as described above, the metal plate 4a can be press-fitted into the ferrite insertion hole 3 in a state where the peripheral side surface and the side surface of the ferrite insertion hole 3 are in close contact with each other.

When the peripheral side surface of the metal plate 4a and the side surface of the ferrite insertion hole 3 are in close contact with each other, it is not necessary to press the yoke 7 for fixing the metal plate 4a, and the yoke 7 is attached at one place at the central portion. It is possible and advantageous in terms of cost.

When the contact becomes dense, the contact resistance decreases, the microwave loss decreases, and the intrusion of external noise and the generation of microwave discharge are eliminated.

Here, looking at the contact structure between the ferrite insertion hole and the metal plate in detail, one or both side surfaces of the metal plate and the ferrite insertion hole are slightly deformed by press-fitting of the metal plate 4a, and the side surface of the ferrite insertion hole 3 is slightly deformed. The metal plate 4a and the convex portion of the metal plate 4a are in close contact with each other. On the other hand, this deformation does not completely fill the recess. Therefore, a gap is created between the recess of the metal plate and the ferrite insertion hole. In order to prevent the microwave from leaking from this gap, the size of this gap is made sufficiently smaller than the wavelength of the microwave used.
Thereby, the leakage of microwaves from this gap can be suppressed to a small level.

FIG. 6 is a front view showing an example of a ferrite insertion hole 3a provided in the waveguide housing 1 and having side surfaces formed in an uneven shape.

Even if the side surface on the ferrite insertion hole 3a side is formed into an uneven shape, the same effect can be obtained.

[Effect of device]

As described above, according to the present invention, the contact resistance of the contact portion between the side surface of the metal plate that presses and fixes the microwave ferrite and the side surface of the ferrite insertion hole is greatly reduced compared to the conventional one, and the microwave loss is reduced. The effect of reducing external noise, making it difficult for external noise to enter, making microwave discharge less likely to occur even in the case of high-power microwave, and simplifying the yoke mounting structure, which is advantageous in terms of cost There is.

[Brief description of drawings]

FIG. 1 is a front view showing an embodiment of the present invention, and FIG. 2 is a first view.
Cross-sectional views taken along the line AA 'shown in the figure, FIGS. 3, 4, and 5 are perspective views showing examples of metal plates, and FIG. 6 shows an example of a ferrite insertion hole whose side surface is formed in an uneven shape. Front view, FIG. 7 is a front view showing an example of a conventional three-aperture circulator of this type of waveguide type nonreciprocal circuit device, FIG.
The drawing is a sectional view taken along the line BB 'shown in FIG. 1 ... Waveguide housing, 2 ... Microwave ferrite, 3 ...
… Ferrite insertion hole, 4a… Metal plate, 6… Magnet, 7…
... Yoke, 8a ... Yoke mounting screw, 9 ... Dielectric plate The same reference numerals in the drawings indicate the same or corresponding portions.

Claims (1)

[Scope of utility model registration request] 1. A metal plate for closing the insertion hole is press-fitted into a ferrite insertion hole provided in an integrally formed waveguide housing, and when fixing the ferrite, a side surface of the metal plate or the ferrite insertion hole is formed. In a waveguide type nonreciprocal circuit element in which at least one of the side surfaces is formed in an uneven shape, the opening size of the gap formed between the metal plate and the ferrite insertion hole due to the concave shape is larger than the wavelength of the microwave used. A waveguide type non-reciprocal circuit device characterized by being made small.