JP2002009501A - Insulated waveguide - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an insulated waveguide that can suppress increase in a transmission loss of a microwave and can increase the breakdown voltage. SOLUTION: Waveguides 3 that are opposed and adjacent to each other are connected together while being insulated by an electric insulator 4. The electric insulator 4 is structured such that it has an insulating cylinder 10 each tip of which is inserted into the waveguides 3 that are opposed and adjacent to each other and an insulating flange section 11 that is integrally connected onto an outer circumference of the insulating cylinder 10 and clamped by flange sections 2 of the waveguides 3 that are adjacent to each other.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an insulated waveguide in which adjacent and mutually opposing waveguides are connected by being insulated by an electric insulator.

[0002]

2. Description of the Related Art When a high voltage surge current flows through a waveguide due to a lightning strike or the like, connected electric equipment may be damaged or an operator may receive an electric shock. An insulated waveguide in which a waveguide is insulated by an electrical insulator and connected is used.

[0003] As this kind of conventional insulated waveguide, there is an insulated waveguide described in JP-A-9-275301.

In this insulated waveguide, as shown in FIG. 4, a waveguide 3 having a structure in which a flange 2 is integrally protruded from each end of a rectangular waveguide main body 1 is adjacent to each other. An electric insulating plate 5 made of tetrafluoroethylene or the like as an electric insulator 4 is disposed between the opposing flange portions 2 so as to cover the holes 6 of the rectangular waveguide main body 1, and the mutual flange portions are provided. Reference numeral 2 denotes a connection fastened by an electrically insulating bolt 7 and a nut 8.

According to such an insulated waveguide, the waveguide 3
Can be prevented by the electric insulator 4.

However, in the insulating waveguide having such a structure, when the surge voltage increases, the thickness of the electric insulating plate 5 must be increased, and when the thickness of the electric insulating plate 5 is increased, the microwave transmission loss is increased. And the leakage of the microwave from between the adjacent flange portions 2 becomes large.

Therefore, as an insulating waveguide for reducing an increase in microwave transmission loss, an insulating waveguide having the structure shown in FIG. 4 corresponds to the hole 6 of the rectangular waveguide main body 1 as shown in FIG. A structure in which a coupling hole 9 is made to pass through an electric insulating plate 5 as an electric insulator 4 is being studied.

[0008]

However, in the insulated waveguide shown in FIG. 5, the creeping distance between the points K via the coupling holes 9 becomes short, and when the surge voltage becomes high, creeping discharge occurs and the insulating There is a problem that the withstand voltage of the waveguide is reduced.

An object of the present invention is to provide an insulated waveguide capable of reducing an increase in microwave transmission loss and increasing a withstand voltage.

It is another object of the present invention to provide an insulated waveguide capable of reducing an increase in microwave transmission loss and capable of sequentially increasing the withstand voltage twice as required.

Another object of the present invention is to provide an insulated waveguide capable of increasing the withstand voltage outside the adjacent flange portion.

Another object of the present invention is to provide an insulated waveguide capable of canceling a reflected wave even when an electric insulator is inserted in a plurality of stages.

[0013]

SUMMARY OF THE INVENTION The present invention is an improvement in an insulated waveguide in which adjacent, opposed waveguides are connected insulated by an electrical insulator.

In the insulated waveguide according to the present invention, the electrical insulator includes an insulating cylinder in which respective tips are inserted into adjacent waveguides facing each other, and an outer periphery of the insulating cylinder. An insulating flange portion connected integrally and sandwiched by flange portions of adjacent waveguides, wherein two adjacent waveguides have this electrical insulator interposed between their opposing ends. And are electrically insulated and connected.

In such an insulated waveguide, each end of an insulating cylinder of an electrical insulator is inserted into an adjacent waveguide, and an insulating flange of the electrical insulator is interposed between the adjacent flanges. As a result, the withstand voltage at the electrically insulating portion can be increased. Thus, a sufficient withstand voltage can be obtained even if the thickness of the insulating flange portion is small, and the withstand voltage at the electrically insulating portion can be increased without increasing the microwave transmission loss.

In the insulated waveguide according to the present invention, the electrical insulator includes an insulated tubular body having respective tips inserted into adjacent and mutually opposed waveguides; And an insulating flange portion integrally connected to the outer periphery and sandwiched by flange portions of adjacent waveguides, and three or more adjacent waveguides are connected between their opposing ends. An insulator is interposed and electrically insulated and connected.

In such an insulated waveguide as well, each end of the insulating cylinder of the electric insulator is inserted into the adjacent waveguide, and the insulating flange of the electric insulator is interposed between the adjacent flanges. As a result, the withstand voltage at the electrically insulating portion can be increased. Thus, a sufficient withstand voltage can be obtained even if the thickness of the insulating flange portion is small, and the withstand voltage at the electrically insulating portion can be increased without increasing the microwave transmission loss. Furthermore, in this insulated waveguide,
Since three or more adjacent waveguides are electrically insulated and connected to each other with the electric insulator interposed between their opposing ends, the three or more waveguides are resistant in accordance with the number N of electric insulators used. The voltage can be increased N times.

Further, the insulating waveguide according to the present invention is characterized in that the insulating flange portion of the electrical insulator has a length protruding outside the flange portion of the waveguide.

According to such an insulated waveguide, creeping discharge outside the flange of the waveguide can be prevented in accordance with the protruding length of the insulated flange.

In the insulated waveguide according to the present invention, the distance between the centers of adjacent electric insulators is set to an integral multiple of 1/4 of the guide wavelength of microwave incident on the waveguide. It is characterized by being.

According to such an insulated waveguide, even if reflected microwaves of incident microwaves are generated due to insertion of an electrical insulator into the waveguide, the phase shifts of these reflected waves cancel each other out, and the microwaves are removed. Can be transmitted without any trouble.

[0022]

1 and 2 show a first embodiment of an insulated waveguide according to the present invention. FIG. 1 is a longitudinal sectional view of the insulated waveguide of this embodiment. FIG. 2 is a perspective view of the electric insulator used in the present example.

As shown in FIG.
Two adjacent waveguides 3 facing each other are electrically insulating
Are insulated and connected. As shown in FIG. 1 and FIG. 2, each of the distal ends of the electric insulator 4 is formed in the rectangular waveguide body 1 of the adjacent waveguide 3 by an electric insulator such as tetrafluoroethylene. Rectangular insulating cylinder 1 to be inserted
0, and a rectangular insulating flange 11 that is integrally connected to the outer periphery of the insulating cylinder 10 and is sandwiched between the flanges 2 of the adjacent waveguides 3. The two waveguides 3 are electrically insulated and connected with the electric insulator 4 interposed therebetween as shown in the drawing. The length of the insulating cylinder 10 inserted into the waveguide 3 is about 約 of the width of the long side of the waveguide 3. Although not shown, the mechanical connection between two adjacent waveguides 3 is performed by fastening with electrically insulating bolts 7 and nuts 8 as in the case of FIG. The electrically insulating bolts 7 and nuts 8 may be made of synthetic resin, respectively, or may be formed by using metal bolts 7 and nuts 8 and flanges of the waveguides 3 through which the bolts 7 pass. Part 2
A structure may be adopted in which an insulating tube is inserted into the hole of the insulating flange portion 11, a bolt 7 is passed through the insulating tube, an insulating washer is applied to each flange portion 2, and the nut 8 is fastened. The insulating flange portion 11 of the electric insulator 4 projects outside the flange portion 2 of the waveguide 3 by a predetermined length.

In such an insulated waveguide, each end of the insulating cylinder 10 of the electric insulator 4 is inserted into the adjacent waveguide 3, and the electric insulator 4 is inserted between the adjacent flanges 2. Since the insulating flange portion 11 is interposed, the withstand voltage at the electrically insulating portion can be increased. Accordingly, a sufficient withstand voltage can be obtained even if the thickness of the insulating flange portion 11 is small, and the withstand voltage at the electrically insulating portion can be increased without increasing the microwave transmission loss.

The insulating flange portion 11 of the electric insulator 4
Is projected out of the flange portion 2 of the waveguide 3,
Creeping discharge outside the flange portion 2 of the waveguide 3 can be prevented according to the length of the protrusion of the insulating flange portion 11.

FIG. 3 is a longitudinal sectional view showing a second embodiment of the insulated waveguide according to the present invention.

In the insulated waveguide of this embodiment, the three adjacent waveguides 3 are electrically interposed between the opposing ends, with the electric insulator 4 having the structure shown in FIG. It is insulated and connected as described above. The distance L between the centers of the mutual electrical insulators 4 is determined to be an integral multiple of 1/4 of the guide wavelength λ of the incident microwave.

In this example, an example in which three waveguides 3 are used is shown. However, even when M (a natural number of 2 or more) waveguides 3 are used, (M-1) number of waveguides 3 are used. The electrical insulator 4 shown in FIG. 2 can be interposed in the connection portion. Also in this case, the distance L between the centers of the adjacent electric insulators 4 is set to an integral multiple of １ ／ of the guide wavelength λ of the incident microwave.

Also in such an insulated waveguide, each end of the insulating cylinder 10 of the electric insulator 4 is inserted into the adjacent waveguide 3, and the electric insulator 4 is inserted between the adjacent flanges 2. Since the insulating flange portion 11 is interposed, the withstand voltage at the electrically insulating portion can be increased. Accordingly, a sufficient withstand voltage can be obtained even if the thickness of the insulating flange portion 11 is small, and the withstand voltage at the electrically insulating portion can be increased without increasing the microwave transmission loss. further,
In this insulated waveguide, three or more adjacent waveguides 3 are electrically insulated and connected to each other with the electric insulator 4 interposed between their opposing ends. The withstand voltage can be increased N times according to the number N of the bodies 4 used.

The insulating flange portion 11 of the electric insulator 4
Is projected out of the flange portion 2 of the waveguide 3,
Creeping discharge outside the flange portion 2 of the waveguide 3 can be prevented according to the length of the protrusion of the insulating flange portion 11.

Further, since the distance L between the centers of the insulating flange portions 11 of the adjacent electric insulators 4 is set to an integral multiple of 1/4 of the guide wavelength of the microwave incident on the waveguide 3, Even if reflected waves of incident microwaves are generated by the insertion of the electrical insulator 4 into the wave tube 3, the phase shifts of these reflected waves cancel each other out, so that microwave transmission can be performed without any trouble.

In the example shown in FIG. 3, the space between the insulating flanges 11 of the adjacent electric insulators 4 is covered with the same insulator so as to integrally surround the outer periphery of the waveguide 3. Can also.

In the above example, an example is shown in which the present invention is applied to a rectangular insulated waveguide. However, the present invention is not limited to this, and can be similarly applied to a circular insulated waveguide. It is.

[0034]

In the insulated waveguide according to the present invention, each tip of the insulating cylinder of the electric insulator is inserted into the adjacent waveguide, and the insulation of the electric insulator is inserted between the adjacent flanges. Since the flange portion is interposed, the withstand voltage at the electrically insulating portion can be increased. Thus, a sufficient withstand voltage can be obtained even if the thickness of the insulating flange portion is small, and the withstand voltage at the electrically insulating portion can be increased without increasing the microwave transmission loss.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a first example of an embodiment of an insulated waveguide according to the present invention.

FIG. 2 is a perspective view of an electric insulator used in the present example.

FIG. 3 is a longitudinal sectional view of a second example of the embodiment of the insulated waveguide according to the present invention.

FIG. 4 is a longitudinal sectional view of a conventional insulating waveguide.

FIG. 5 is a longitudinal sectional view of an insulated waveguide obtained by improving the insulated waveguide of FIG. 4;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Rectangular waveguide main body 2 Flange part 3 Waveguide 4 Electrical insulator 5 Electrical insulating plate 6 Hole 7 Bolt 8 Nut 9 Coupling hole 10 Insulating cylinder 11 Insulating flange

Claims (4)

[Claims] 1. An insulated waveguide in which adjacent and mutually opposed waveguides are insulated and connected by an electrical insulator, wherein said electrical insulator is a part of said adjacent and mutually opposed waveguides. A structure having an insulating cylindrical body into which each end is inserted, and an insulating flange portion integrally connected to the outer periphery of the insulating cylindrical body and sandwiched by flange portions of the adjacent waveguides. An insulated waveguide, wherein two adjacent waveguides are electrically insulated and connected with the electric insulator interposed between their opposing ends. 2. An insulated waveguide in which adjacent and mutually opposing waveguides are insulated and connected by an electric insulator, wherein said electric insulator is adjacent to said mutually opposing waveguides. A structure having an insulating cylindrical body into which each end is inserted, and an insulating flange portion integrally connected to the outer periphery of the insulating cylindrical body and sandwiched by flange portions of the adjacent waveguides. An insulated waveguide, wherein three or more adjacent waveguides are electrically insulated and connected with each other with the electric insulator interposed between their opposing ends. 3. The insulated conductor according to claim 1, wherein the insulating flange portion of the electrical insulator has a length protruding outside the flange portion of the waveguide. Wave tube. 4. The distance between the centers of adjacent electric insulators is 1/1 / s of the guide wavelength of microwave incident on the waveguide.
3. The method according to claim 2, wherein the number is set to an integral multiple of 4.
4. The insulated waveguide according to claim 1.