JP2523263Y2 - Arc light detector for microwave tube - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION INDUSTRIAL APPLICATION The present invention relates to an arc light detecting device incorporated in a high power transmission device using a microwave tube, and more particularly to a device for separating arc light from light emitted from a microwave tube. The present invention relates to an arc light detection device used in the above.

2. Description of the Related Art In a high-power transmission device using a microwave tube such as a satellite communication, a rectangular waveguide is usually used as an output circuit. However, when a microwave is introduced into the waveguide, the inside of the waveguide is reduced. When an arc discharge occurs due to the potential difference generated in the above, a high-frequency electric field is short-circuited at the point where the arc discharge occurs, a reflected wave is generated, and a standing wave is generated in the waveguide. Sometimes, the voltage of the standing wave is located at the maximum point of the ceramic sealing window of the microwave tube, and a creeping discharge is started on the surface of the ceramic sealing window, and the heat generated at this time destroys the ceramic. May cause When the arc light generated by the arc discharge travels toward the microwave tube as an energy supply and reaches the ceramic sealing window, the ceramic sealing window is locally heated by the heat of the arc light and the ceramic sealing window is heated. May be destroyed.

In a conventional transmission device, in order to protect the microwave tube against such arc discharge and arc light, a small hole is provided in a tube wall of a rectangular waveguide forming an output circuit of the microwave tube, and a small hole is formed through the small hole. By detecting the occurrence of an arc in the rectangular waveguide, the voltage supplied to the microwave tube is cut off. Usually, this arc light detection device is placed near the output circuit of the microwave tube, and the arc light detection device looks directly at the ceramic sealing window of the microwave tube on the one hand, and in the rectangular waveguide on the load side on the other hand. It is arranged at the bend of E bend or H bend so as to see through. That is,
Since it is difficult to predict in advance where the arc discharge will occur in the output rectangular waveguide, a position that can respond to the occurrence of arc discharge on either side of the arc light detection device is selected. Have been.

Problems to be Solved by the Invention In the arc light detecting device provided in the conventional transmitting device described above, since one of the devices directly looks at the ceramic sealing window of the microwave tube, the light generated in the microwave tube is ceramic. Even when the arc light detection device enters the above-described arc light detection device through the sealing window, the protection circuit operates assuming that an arc discharge has occurred, that is, a malfunction may occur.
In particular, in the case of a microwave tube for a high frequency band, in order to improve the electrical characteristics of the ceramic sealing window, the thickness of the ceramic must be extremely thin, and as a result, the light transmission And malfunctions are likely to occur. For example,
In a 30Hz microwave tube, the thickness of the ceramic sealing window is about 0.5mm.

Further, when the temperature of a part of the high-frequency circuit portion inside the microwave tube, for example, the temperature of the tuner portion in a klystron or the temperature of the slow wave circuit portion in a traveling wave tube increases, light is generated. In particular, in the case of a high-output microwave tube, light is often emitted from inside the microwave tube.

Accordingly, an object of the present invention is to provide an arc light detecting device for a microwave tube which does not sense light emitted from the inside of the microwave tube but senses only arc light generated in the waveguide.

Means for solving the problem The arc light detecting device for a microwave tube according to the present invention detects the arc light generated in the waveguide facing the ceramic sealing window of the output circuit of the microwave tube to detect the microwave light. An arc light detection device for a microwave tube used to cut off a supply voltage to a microwave, wherein a small hole communicating obliquely with the inside and outside is provided so as to penetrate the tube wall of the waveguide, and is inserted into the small hole. And a photoelectric conversion element optically coupled to one end of the light introduction tube outside the waveguide, and an axis in the through direction of the small hole and the light introduction tube. The axis of the light guide tube in the longitudinal direction forms an acute angle with the longitudinal axis of the waveguide, and the ceramic sealing window does not exist on an extension of the light guide tube in the longitudinal direction; and The other end of the light introduction tube is closer to the inner wall surface of the waveguide. It is characterized in that it does not protrude inward.

In a preferred embodiment of the present invention, the light guide tube is inserted into a small hole of the waveguide such that an extension of the light guide tube forms a certain acute angle, preferably an acute angle, with the central axis of the waveguide. The extension of the light introducing tube intersects the inner wall of the waveguide in front of the ceramic sealing window.

Operation As described above, the arc light detection device for a microwave tube according to the present invention has a light guide tube inserted into a small hole of a rectangular waveguide, the axis of which intersects the rectangular waveguide at an acute angle. Because it does not intersect, the light generated in the microwave tube
Since the light enters the light introducing tube at an angle formed by the two axes, it is difficult to detect the light, and the arc light generated in the waveguide and the reflected light thereof can be mainly detected from various angles.

EXAMPLES Next, the present invention will be specifically and more specifically described with reference to the accompanying drawings, but the present invention is not limited thereto.

Embodiment 1 FIG. 1 shows a longitudinal sectional view of an embodiment of the present invention, in which a microwave tube 1 is provided with a ceramic sealing window 2,
This forms part of the vacuum envelope. The output circuit of the microwave tube 1 includes a waveguide 3, an output flange 4, and the like. A rectangular waveguide 5 connected to a load is connected to the output flange 4, and the load side of the rectangular waveguide 5 is an E-bend and is bent upward. Rectangular waveguide 5
Has a small hole 6 in the bend portion, and a light introducing tube 7 in the small hole 6.
Is inserted, and one end surface of the light introducing tube 7 is connected to the rectangular waveguide 5.
You can see inside. The other end surface of the light introducing tube 7 faces a photoelectric conversion element 8 such as a phototransistor or a photodiode. The photoelectric conversion element 8 is connected to the detection circuit 9. Here, the axis 10 of the light introducing tube 8 on the side facing the rectangular waveguide 5 has an angle θ with respect to the axis 11 of the rectangular waveguide 5. The angle θ is selected so that the ceramic sealing window 2 is not positioned on the extension of the axis 10 of the light introducing tube 8.

With the above-described configuration, the light 12 generated in the microwave tube enters the light introducing tube 8 at an angle of θ. On the other hand, the arc light 13 generated in the rectangular waveguide 5 is reflected in the rectangular waveguide 5 and enters the light introducing tube 8 from various angles. Therefore, the intensity of the light incident on the light introducing tube 8 is higher in the case of the arc light 13 when comparing the arc light 13 with the light 12 from inside the microwave tube, so that the sensitivity of the detection circuit 9 is appropriately adjusted. By adjusting the arc light 13
, But not to the light 12 from inside the microwave tube.

Although the microwave tube of the above embodiment was operated for a total operating time of 2000 hours at intervals of 4 hours each of 25 hours, from the observation of the magnetic field caused by the arc discharge, the malfunction of the protection circuit was limited to only 8 times. There was found.

Embodiment 2 FIG. 2 shows a longitudinal sectional view of another embodiment of the present invention, wherein the rectangular waveguide 5 is a straight waveguide, but the small hole 6 is inclined with respect to the axis of the rectangular waveguide 5. It is provided. A light introducing tube 7 is inserted into the small hole 6 and looks inside the rectangular waveguide 5. On the other surface of the light introducing tube 7, a photoelectric conversion element 8 is arranged. In this embodiment, the rectangular waveguide 5 does not need to be E-bend or H-bend, and there is an advantage that the layout of the waveguide is not limited.

As in Example 1, the microwave tube of this embodiment was
After a total operating time of 2000 hours with a time interval of 4 hours, observation of the magnetic field caused by the arc discharge revealed that the protection circuit malfunctioned only 12 times.

Effect of the present invention As described above, the arc light detecting device for a microwave tube according to the present invention has a structure in which it is difficult to detect light generated from inside the microwave tube, and mainly detects only arc light generated in a rectangular waveguide. Therefore, the protection circuit of the microwave tube does not operate more than necessary, and the reliability of the transmission device can be improved.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of an embodiment of the microwave tube arc light detecting device of the present invention, and FIG. 2 is a longitudinal sectional view of another embodiment of the microwave tube arc light detecting device of the present invention. is there. (Main reference numbers) 1 ... Microwave tube 2 ... Ceramic sealing window 3 ...
Waveguide, 4 ... output flange, 5 ... rectangular waveguide, 6 ...
... Small hole, 7 ... Light introduction tube, 8 ... Photoelectric conversion element, 9 ...
Detection circuit, 10: axis of light introducing tube, 11: axis of rectangular waveguide, 12: light from inside microwave tube, 13: arc light, θ: angle

Claims (1)

(57) [Scope of request for utility model registration] An arc light for a microwave tube used for detecting an arc light generated in a waveguide facing a ceramic sealing window of an output circuit of the microwave tube and cutting off a supply voltage to the microwave tube. In the detection device, a small hole communicating with the inside and outside provided so as to penetrate the tube wall of the waveguide obliquely, a light introduction tube made of a light transmitting material inserted into the small hole, A photoelectric conversion element optically coupled to one end of the light introduction tube outside the tube, wherein an axis in the through direction of the small hole and an axis in the tube length direction of the light introduction tube have a tube length of the waveguide. At an acute angle with the axis of the light guide tube, and the ceramic sealing window does not exist on an extension of the light guide tube in the tube length direction, and the other end of the light guide tube is inside the inner wall surface of the waveguide. Microwave characterized in that it does not protrude Use arc light detection device.