JPH07307602A - Isolator for high power - Google Patents

Abstract

PURPOSE:To form an isolator for high power with high power resistance and improved heat radiation property. CONSTITUTION:A dielectric 5 is provided between the opposing surfaces 13 of a pair of ferrite 2 provided inside this isolator 1. The dielectric 5 is in contact with the respective opposing surfaces of the ferrite, covers peripheral edges 14 and is attached. Further, for the ferrite, metal is vapor deposited to joined surfaces with a case body 3 and the vapor deposition surfaces 6 are stuck by molten metal such as solder or the like. Thus, since the peripheral edges of the opposing surfaces of the ferrite are covered with the dielectric, microwave discharging is not generated in the opposing surfaces and the peripheral edges. Also, since the dielectric is extended near the case body 3, the heat radiation property is improved as well since heat around the opposing surfaces is transmitted through the dielectric and the heat around the case body is transmitted through the metal for adhesion.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high power isolator having high power resistance and excellent heat dissipation.

[0002]

2. Description of the Related Art In a Y-branch type isolator in which a waveguide is formed in a Y-shape and an electromagnetic wave travels in a predetermined direction by an external magnetic field, a ferrite is arranged at the center of the Y-shaped branch point. ing. In such a Y-branch type isolator for high power or used in vacuum, heat generation due to the high frequency loss of the ferrite and generation of microwave discharge in vacuum become a problem.

For example, in the 12 GHz band, the isolator has an insertion loss of a little less than 0.1 dB, and when a microwave having an average power of 800 w is applied to this isolator, it becomes 1
A little less than 8.2w of heat is generated. When the temperature of the ferrite rises due to such heat generation, the ferrite characteristics are changed, and the performance of the isolator deteriorates.

Therefore, conventionally, as shown in FIG. 4, the ferrite 2 is divided into two, metal is vapor-deposited on one surface of each ferrite 2, and the ferrite 2 is soldered to the upper surface and the bottom surface in the Y-branch waveguide, respectively. The heat generated in the ferrite by high frequency is directly attached to the housing 3 by conduction.
A structure for preventing the temperature of the ferrite 2 from rising, or as shown in FIG.
It is known that a dielectric 33 is inserted in a gap between two ferrites to improve the electric power resistance between the ferrites 2 (see Japanese Utility Model Laid-Open No. 64-13801).

[0005]

However, in the structure shown in FIG. 4 in which the space between the pair of ferrites 2 is a space, the space between the two formed by the ferrites arranged in the isolator, particularly When the electric field strength at the outer edge of the ferrite is large and a peak power of several kw or more is applied, high frequency discharge is caused between the ferrites 2,
There was a problem that the ferrite was crushed.

Even when the dielectric 33 is inserted between the ferrites 2 as shown in FIG. 3, the electric field strength at the outer edge of the ferrite 2 is large, and similarly, when a peak power of several kw or more is applied, a high frequency discharge is generated. There was a problem causing.

Further, most of the heat radiation of the ferrite 2 is transmitted to the wall surface such as the upper surface and the bottom surface of the waveguide, and even if the dielectric 33 is connected to the facing surface of the ferrite 2, it is generated in the ferrite 2. It is not effective in transferring heat to the outside, and there is a problem that heat is accumulated.

SUMMARY OF THE INVENTION The present invention solves the above problems and provides a high power isolator having stable and high performance in which the power resistance of the ferrite provided inside the high power isolator is improved and the heat dissipation is improved. The purpose is to provide.

[0009]

According to the present invention, in order to solve the above problems, in a high power isolator in which a pair of ferrites are mounted inside a waveguide so as to face each other, a dielectric is provided between the pair of ferrites. Is provided so as to cover the peripheral edge of the opposing surface to construct a high power isolator.

Further, when metal is vapor-deposited on one surface of the ferrite and the ferrite is mounted in the waveguide, the metal vapor-deposited surface is directed to the upper surface or the bottom surface of the waveguide and the space between them is mounted by molten metal. .

Further, the above condition is applied to the Y-branch isolator divided into Y-shapes.

Further, the dielectric has a high insulation resistance, a low dielectric loss and a high thermal conductivity.

[0013]

By providing a dielectric on the opposing surfaces of a pair of ferrites provided in the isolator so as to cover the periphery of the opposing surfaces, it is possible to prevent discharge between the opposing surfaces and at the peripheral edge of the opposing surfaces, and Since the end portion of the body approaches the inner surface of the housing, the heat generated in the ferrite can be conducted to the housing, and the heat dissipation can be improved.

Further, since the ferrite is adhered to the housing by molten metal such as solder, the thermal conductivity to the housing can be further enhanced. Furthermore, by making the dielectric material have high insulation resistance, low dielectric loss and high thermal conductivity, it is possible to further improve the power resistance and heat dissipation.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a high power isolator according to the present invention will be described with reference to FIGS.

The isolator 1, as shown in FIG.
It is a branch type isolator and is composed of a housing 3 and a ferrite 2 and the like provided inside the housing 3. The housing 3 is
It is made of a metal such as aluminum, has a waveguide inside, and has waveguide openings 21, 22, and 23 on three sides. The ferrite 2 is arranged at a predetermined position of the housing 3 so that the microwaves from the waveguide openings 21 and the like are guided only in a predetermined direction.

FIG. 1 is a partial cross-sectional view showing the ferrite 2. As shown in FIG. 1, the ferrite 2 has a vapor deposition surface 6 formed by vapor-depositing a metal on one side, and solder or the like is formed on the vapor deposition surface 6. The molten metal is applied and attached to the upper surface and the lower surface of the inner surface of the housing 3. A dielectric 5 is attached between the pair of ferrites 2.

The dielectric 5 is made of aluminum nitride and has a high insulation resistance, a low dielectric loss, and a high thermal conductivity. The dielectric 5 is in close contact with both facing surfaces 13 of the ferrite 2 and further has a peripheral edge 14 thereof. It has a covering shape and is integrally bonded to the ferrite 2 with an adhesive or the like.

Therefore, in the isolator 1, in the facing surface 13 of the ferrite 2, the power withstanding property at the peripheral edge 14 is increased, and in particular, the discharge between the ferrite 2 at the peripheral edge 14 can be prevented. Furthermore, since the end portion 9 of the dielectric 5 is extended to the side of the housing 3, heat generated near the facing surface 13 is conducted to the vicinity of the housing 3 and also generated near the housing 3. Heat is directly transferred to the housing 3 through the vapor deposition surface 6,
The heat dissipation is improved.

Particularly, in the satellite-mounted high power isolator, since the ferrite gap portion where the electric field is most concentrated and the peripheral edge thereof are covered with the dielectric 5 having a high insulation resistance, that portion is also kept in vacuum. The acceleration and traveling of electrons by microwaves are blocked by the dielectric 5 and do not occur. Therefore, microwave discharge in vacuum due to electron traveling does not occur.

On the other hand, even under atmospheric pressure, the insulation resistance of the dielectric is higher than that of air, making it difficult to discharge.

The isolator 2 is not limited to the Y-branch type,
It may be a unidirectional tube, a circulator or the like.

The dielectric 5 is not limited to aluminum nitride, but may be any other material as long as it has high insulation resistance, low dielectric loss, and high thermal conductivity. Further, the dielectric 5 only needs to cover at least the peripheral edge 14 of the ferrite 2, and the ferrites 2 do not have the same shape.
Further, only one ferrite 2 side may be provided. Furthermore, the edge of the dielectric 5 may be extended until it contacts the inner surface of the housing 3,
In this way, the heat generated in the ferrite 2 causes the heat generated in the dielectric 5
It is directly transmitted to the housing 3 through the through, so that the heat dissipation becomes higher and the temperature rise can be suppressed.

The shape of the ferrite 2 is not limited to a cylindrical shape, a rectangular parallelepiped shape, a triangular prism shape or the like.

[0025]

According to the high power isolator of the present invention,
Between the facing surfaces of the pair of ferrites provided inside the isolator, the dielectric is provided so as to cover the peripheral edges of the facing surfaces.
Power resistance at the peripheral edge of ferrite can be improved, heat in the vicinity of the facing surface can be transferred to the mounting surface such as the housing, heat dissipation in the vicinity of the facing surface can be improved, and the temperature rise of ferrite can be suppressed, and high performance and stable It is possible to provide a high-performance isolator for high power.

[Brief description of drawings]

FIG. 1 is a partial sectional view showing an embodiment of an isolator of the present invention.

FIG. 2 is a perspective view showing an embodiment of the isolator of the present invention.

FIG. 3 is a sectional view showing a structure of a conventional isolator.

FIG. 4 is a sectional view showing a structure of a conventional isolator.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Isolator 2 Ferrite 3 Housing 5 Dielectric 6 Deposition surface 9 End 13 Opposing surface 14 Periphery

Claims (6)

[Claims] 1. An isolator in which a pair of ferrites are mounted inside a waveguide so as to face each other, wherein a dielectric is provided on a facing surface of the ferrite in a state of covering a peripheral edge of the facing surface of the ferrite. High power isolator. 2. The metal is vapor-deposited on one surface of the ferrite, and the ferrite is opposed to the inside of the waveguide so that the metal vapor-deposited surfaces are attached to the top surface and the bottom surface of the waveguide by molten metal, respectively. The high power isolator according to claim 1, wherein the isolator is a high power isolator. 3. The isolator is a Y-branch isolator divided into Y-shapes.
Alternatively, the high power isolator described in 2. 4. The high power isolator according to claim 1, wherein the dielectric covers the entire periphery of the ferrite. 5. The high power isolator according to claim 1, wherein the dielectric covers the entire ferrite. 6. A dielectric material having high insulation resistance, low dielectric loss and high thermal conductivity.
2. The high power isolator according to any one of 1.