Magnetron

Abstract

To provide a magnetron capable of suppressing an oscillation stop due to the generation of an abnormal oscillation while preventing damages of a coil.SOLUTION: A magnetron is a high-output type industrial magnetron. Each of all plate-like vanes 52 belonged to a first plate-like vane group 52g1, and all plate-like vanes 52 belonged to a second plate-like vane group 52g2 includes at least three or more same numbers of penetration holes 52h at near from a tip end of a direction of a center shaft. As using n a numeric value indicating an odd number that is started from 1, nth pressure equalization annular 64_n is penetrated so as to be contacted to nth penetration hole 52hn of all of the plate-like vane belonged to the first plate-like vane group 52g1, and a n+1th pressure equalization annular 64_n+1 is penetrated so as to be contacted to a n+1th penetration hole 52gn+1 of all of the plate-like vane belonged to the second plate-like vane group 52g2.SELECTED DRAWING: Figure 5

Description

[Technical field]

[0001] The present invention relates to a magnetron. [Background technology]

[0002] The magnetron uses a strap ring to equalize the potential of the plate-shaped vanes and to suppress the effects of unwanted radiation that causes noise.

[0003] Patent Document 1 discloses a magnetron comprising an anode cylinder extending along a central axis, a number of plate-shaped vanes joined to the anode cylinder and extending toward the central axis with their free ends forming an inscribed circle surrounding the central axis, a large diameter strap ring and a small diameter strap ring having a smaller diameter than the large diameter strap ring and joined to cutouts provided on the sides of the vanes between the anode cylinder and their free ends, which alternately short-circuit the vanes, wherein the inner diameter of the large diameter strap ring and the outer diameter of the small diameter strap ring are equal, and the vanes are arranged in the cutouts with a step between them in the central axis direction. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2012-169169 A Summary of the Invention [Problem to be solved by the invention]

[0005] In the technology disclosed in Patent Document 1, the inner diameter of the large diameter strap ring and the outer diameter of the small diameter strap ring are made equal, and the large diameter strap ring and the small diameter strap ring are arranged with a step on the end face of the vane so that they do not come into contact with each other. By making the inner diameter of the large diameter strap ring and the outer diameter of the small diameter strap ring equal, the amount of scrap can be reduced when the strap ring is pressed from a plate, improving the material efficiency of the strap ring and reducing the manufacturing cost.

[0006] However, in high-output industrial magnetrons, the method of installing a strap ring (hereinafter referred to as a strain-equalizing ring) in Patent Document 1 has two problems.

[0007] The first issue is that the equalizing ring is designed with notches on the side of the plate-shaped vanes and is equipped with a large-diameter equalizing ring and a small-diameter equalizing ring that are joined together to alternately short-circuit the plate-shaped vanes, but with this structure, the fundamental microwaves can flow through the vacuum tube to the coil side, causing the coil to burn out.

[0008] The second problem is that the effect of unnecessary radiation on the fundamental wave cannot be completely suppressed, which may cause abnormal oscillation.

[0009] The present invention has been made in consideration of the above-mentioned problems, and has an object to provide a magnetron that can prevent damage to the coil and suppresses oscillation halts due to the occurrence of abnormal oscillations. [Means for solving the problem]

[0010] In order to achieve the above object, the magnetron of the present invention is a high-power industrial magnetron, comprising an anode cylinder, a plurality of plate-shaped vanes, each having one end fixed to a plurality of different fixing portions on the inner wall surface of the anode cylinder and each having the other end extending from the fixing portion toward the central axis of the magnetron, and a predetermined number of equalizing rings arranged inside the anode cylinder, the plurality of plate-shaped vanes including a first plate-shaped vane group consisting of a set of the plate-shaped vanes arranged in a row in a clockwise or counterclockwise direction starting from a plate-shaped vane at a predetermined position, and a set of the plate-shaped vanes excluding the first plate-shaped vane group. and a second plate-shaped vane group consisting of a collection of vanes, wherein all of the plate-shaped vanes belonging to the first plate-shaped vane group and all of the plate-shaped vanes belonging to the second plate-shaped vane group have the same number of through holes, at least three or more, near their tips in the direction of the central axis, and the n-th through hole penetrates the n-th pressure equalizing ring so as to contact the n-th through hole of all of the plate-shaped vanes belonging to the first plate-shaped vane group, where n is an odd number starting with 1, and the n+1-th through hole penetrates the n-th pressure equalizing ring so as to contact the n+1-th through hole of all of the plate-shaped vanes belonging to the second plate-shaped vane group. Other aspects of the present invention will be described in the embodiments described later. Effect of the Invention

[0011] According to the present invention, damage to the coil can be prevented and oscillation stoppage due to the occurrence of abnormal oscillation can be suppressed. [Brief description of the drawings]

[0012] [Figure 1] FIG. 1 is a diagram showing the structure of a high-output industrial magnetron according to an embodiment of the present invention. [Figure 2A] FIG. 13 is a diagram showing an arrangement when the plate-shaped vane has three through holes. [Figure 2B] FIG. 13 is a diagram showing an arrangement of four through holes in a plate-shaped vane. [Figure 3A] FIG. 13 is a diagram showing another arrangement when the plate-shaped vane has three through holes. [Figure 3B] FIG. 13 is a diagram showing another arrangement when the plate-shaped vane has four through holes. [Figure 4] FIG. 2 is a diagram showing the arrangement of plate-shaped vanes on an anode cylinder. [Diagram 5] FIG. 13 is a diagram showing a method of arranging through holes and equalizing rings. [Figure 6] FIG. 13 is a diagram showing the correlation between a strap ratio and unwanted radiation. [Figure 7] FIG. 13 is a diagram showing the effect of three equalizing rings. [Figure 8] FIG. 4 is a diagram showing the connection between equalizing rings. [Figure 9] FIG. 2 is a diagram showing the detailed structure of a high-power industrial magnetron according to the present embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment for carrying out the present invention will be described in detail with reference to the accompanying drawings. 1 is a diagram (cross-sectional view) showing the structure of a high-power industrial magnetron 100 according to this embodiment. The high-power industrial magnetron 100 includes an anode cylinder 53, a plurality of plate-shaped vanes 52 each having one end fixed to a plurality of different fixing parts 52f (see FIG. 4) on the inner wall surface of the anode cylinder 53 and the other end extending from the fixing part 52f toward the central axis, a cathode filament 51 disposed in the center of the anode cylinder 53, and permanent magnets 54, 54a. A heater is wound around the cathode filament 51, and applying a predetermined current thereto causes the cathode filament 51 to emit thermoelectrons. The thermoelectrons are attracted to the anode cylinder 53, but are caused to rotate and circulate around the cathode by the magnetic field generated by the magnet, and are resonated in a resonant cavity (described later), which is a cavity formed by the inner wall surface of the anode cylinder 53 and the multiple plate-like vanes 52, and the energy is extracted as microwaves from the output section 69 (antenna). Details will be described later with reference to Figs. 2A to 5, but a through hole 52h (see Fig. 2A, for example) is provided at the end of the multiple plate-like vanes 52, and a structure is formed in which the pressure equalizing ring 64 is penetrated.

[0014] In addition, industrial magnetrons are generally considered to be low-output types when they are around 2 to 10 kW, and high-output types when they are over 10 kW. In addition, magnetrons at the level of household use and several kW are sometimes called low-output types, and magnetrons with an output of more than a few kW are sometimes called high-output types.

[0015] 9 is a diagram showing the details of the structure of a high-power industrial magnetron according to this embodiment. In the magnetron 100, 51 is a cathode filament (directly heated spiral cathode) that serves as a thermoelectron emission source, 52 is a plurality of plate-shaped vanes (anode vanes), and 53 is an anode cylinder.

[0016] Reference numerals 54 and 54a denote annular permanent magnets, 55 and 55a denote magnetic poles, and 56 and 56a denote yokes. Reference numeral 57 denotes an antenna lead, 58 denotes a cylindrical antenna block, 61 denotes output side ceramic (insulator), 63 denotes an action space, 64 denotes a pressure equalizing ring, 66 and 67 denote rod-shaped upper and lower sealing metals, 68 and 68a denote upper and lower anode plates, and 69 denotes an output section. This output section 69 is configured to include the antenna lead 57 and the antenna block 58. The antenna lead 57 and the antenna block 58 are joined by a method such as silver brazing or arc welding.

[0017] Numeral 70 denotes a magnetic circuit portion, which is configured to include permanent magnets 54, 54a and magnetic poles 55, 55a, which are magnetic generating sources, and yokes 56, 56a. Numeral 71 denotes an upper end shield (also called an output side end shield), 72 denotes a lower end shield (also called an input side end shield), 73 denotes a center lead of the cathode lead, and 74 denotes a side lead of the cathode lead.

[0018] Reference numeral 75 denotes an input side ceramic, and 78 denotes a cathode section. This cathode section 78 is composed of a cathode filament 51 serving as a thermoelectron emission source, an upper end shield 71, a lower end shield 72, and cathode leads 73, 74, etc. Reference numeral 79 denotes an anode section, and this anode section 79 is fixed to the multiple plate-like vanes 52 and the anode cylinder 53 by brazing or the like, or is integrally formed with the anode cylinder 53 by extrusion molding. Reference numeral 76 denotes a terminal plate, and 80 denotes an exhaust pipe.

[0019] In the magnetron 100 having such components, the yokes 56, 56a constitute the magnetic circuit section 70, but also serve as a housing for accommodating the permanent magnets 54, 54a, the magnetic poles 55, 55a, the antenna lead 57, the cathode section 78, and the anode section 79, and are disposed on the microwave output side and are also used as a coupling member for connecting to an external mechanism (not shown). The housing is configured such that one yoke 56 is box-shaped with an opening on the bottom, and the other yoke 56a is shaped like a lid that covers the opening. The yokes 56 and 56a are screwed together with screws 205, and the yoke 56 is further screwed to the cooling mechanism 77 with screws 205a.

[0020] Magnetic poles 55, 55a made of a ferromagnetic material such as soft iron and cylindrical permanent magnets 54, 54a are arranged above and below the anode cylinder 53. The magnetic flux generated from the permanent magnets 54, 54a passes through the magnetic poles 55, 55a and enters the interaction space 63 formed between the cathode filament 51 and the plate-shaped vanes 52, and applies a necessary DC magnetic field in the axial direction, which is the vertical direction of the magnetron 100.

[0021] This DC magnetic field exerts the following effect. In other words, when the magnetron 100 body axis is set perpendicular to the horizontal plane, and a magnetic flux is applied perpendicularly (in the axis direction) to electrons flying horizontally from the cathode filament 51 toward the plate-shaped vanes 52, a Lorentz force is applied to the electrons. This Lorentz force causes the electrons to fly while circling horizontally in a spiral, and a high-frequency electric field is formed in the plate-shaped vanes 52.

[0022] The cathode filament 51 emits electrons when a negative high voltage of 4 kV to 8 kV DC is applied, and these electrons undergo a spiral motion due to the action of the electric field and magnetic field as described above, forming a high-frequency electric field in each plate-like vane 52. This formed high-frequency electric field is output from the antenna block 58 through the antenna lead 57 to an external device (not shown).

[0023] In addition, taking into consideration the electron emission characteristics and workability, the cathode filament 51 is generally a tungsten wire containing about 1% thorium oxide (ThO2), and is supported by an upper end shield 71, a lower end shield 72, and cathode leads 73, 74. From the standpoint of heat resistance and workability, the cathode leads 73, 74 are generally made of molybdenum (Mo), and are connected to the choke coil 81 via a terminal plate 76 brazed to the upper surface of the input side ceramic 75 with silver solder or the like.

[0024] A filter structure 85 is attached to the bottom of the magnetron 100, and is made up of a filter case 83 that supports a choke coil 81 and a feedthrough capacitor 82, and a lid 84 that closes the filter case 83. The choke coil 81 connected to the terminal board 76 forms an LC filter together with the feedthrough capacitor 82, and suppresses low-frequency components transmitted from the cathode leads 73, 74. However, high-frequency components are shielded by the filter case 83 and its lid 84. The cooling mechanism 77 installed on the outer periphery of the anode cylinder 53 has a cooling water passage 77a through which cold water passes that runs around inside, and the cold water passing through the passage diffuses heat associated with the operation of the magnetron 100.

[0025] The exhaust pipe 80 is for removing gas from inside the main body of the magnetron vacuum tube 59 in which the cathode section 78, the anode section 79, and part of the output section 69 are enclosed. After the gas is removed to create a vacuum state, the tip of the exhaust pipe 80 is sealed.

[0026] In the high-output magnetron 100 described above, the first problem of coil damage and the second problem of suppressing the effect of unnecessary radiation on the fundamental wave are solved as follows.

[0027] (Regarding the first issue) The first problem is solved as follows. FIG. 2A is a diagram showing an arrangement in which the plate-shaped vane 52 has three through holes 52h. FIG. 2B is a diagram showing an arrangement in which the plate-shaped vane 52 has four through holes 52h. FIG. 2A and FIG. 2B show diagrams showing the placement of the through holes 52h of the plate-shaped vane 52. In order to solve the problem of coil burnout caused by the fundamental wave, the equalizing ring is not provided with a notch on the side of the plate-shaped vane 52, but rather has a through hole at the end of the plate-shaped vane 52, through which the equalizing ring 64 penetrates. The microwave is prevented from traveling through the lower part of the vacuum tube 59 body and flowing to the choke coil 81 side. The vacuum tube 59 body is a part that encloses the cathode part 78, the anode part 79, and a part of the output part 69.

[0028] The plate-shaped vanes 52 have the same number of through holes 52h vertically arranged near the end in the central axis direction. The hole diameter will be described later with reference to FIG.

[0029] In this embodiment, in the case of through hole 52hn, n is a numerical value indicating an odd number starting with 1, and increases as 1, 3, 5, .... Also, the n+1th is a numerical value indicating an even number, such as 2, 4, 6, ....

[0030] For example, in the case where there are three through holes as shown in FIG. 2A, when n=1, the through hole is 52h1 (first), the through hole is 52h2 (second), and when n=3, the through hole is 52h3 (third).

[0031] 2B, when n = 1, the through holes are 52h1 (first) and 52h2 (second), and when n = 3, the through holes are 52h3 (third) and 52h4 (fourth). Note that the arrangement of the through holes is not limited to this.

[0032] FIG. 3A is a diagram showing another arrangement when the plate-shaped vane 52 has three through holes. FIG. 3B is a diagram showing another arrangement when the plate-shaped vane has four through holes. As shown in FIG. 3A and FIG. 3B, the center points of the through holes do not necessarily need to be arranged on the same vertical line, and they may be arranged at positions shifted from the central axis direction, or may be arranged in two rows in the vertical line direction. However, in terms of processing, it is preferable to arrange them in the vertical line direction. Compared with FIG. 2 and FIG. 2B, FIG. 3A and FIG. 3B are effective when there is a limit in the height direction of the plate-shaped vane 52.

[0033] 4 is a diagram showing the arrangement of the plate-shaped vanes 52 on the anode cylinder 53. The plate-shaped vanes 52 are arranged radially around the central axis of the magnetron, with one end fixed to the inner wall surface of the anode cylinder 53 and the other end extending toward the central axis of the magnetron. The plurality of plate-shaped vanes 52 form a first plate-shaped vane group 52g1 (1 in the figure) consisting of a collection of plate-shaped vanes arranged in a row clockwise or counterclockwise starting from a plate-shaped vane at a predetermined position, and a second plate-shaped vane group 52g2 (2 in the figure) consisting of a collection of plate-shaped vanes excluding the first plate-shaped vane group 52g1.

[0034] Fig. 5 is a diagram showing a method of arranging the through holes 52h and the pressure equalizing ring 64. For convenience of explanation, in Fig. 5, the plate-like vanes 52 shown in Fig. 4 are drawn side-by-side.

[0035] In this embodiment, at least three or more equal number of through holes 52h are vertically arranged near the end in the central axis direction of each plate-shaped vane 52, and one equalizing ring 64 is passed through the first through hole 52h1, one through the second through hole 52h2, and one through the third through hole 52h3, so it is essential to provide three or more equalizing rings 64. Note that in this figure, an example in which the minimum configuration of three through holes 52h and three equalizing rings 64 are provided will be described.

[0036] All the plate-shaped vanes 52 belonging to the first plate-shaped vane group 52g1 have through holes of two different shapes, and through holes in the same order have the same shape. All the plate-shaped vanes 52 belonging to the second plate-shaped vane group 52g2 have through holes of two different shapes, and through holes in the same order have the same shape.

[0037] Furthermore, in all the plate-like vanes 52 belonging to the first plate-like vane group, the first and third through holes have different areas from the second through hole. Similarly, in all the plate-like vanes 52 belonging to the second plate-like vane group, the first and third through holes have different areas from the second through hole.

[0038] Specifically, as shown in FIG. 5, the size of the first through hole 52h1 in the first plate-shaped vane group 52g1 and the second plate-shaped vane group 52g2 is such that if the first through hole of a plate-shaped vane belonging to the first plate-shaped vane group 52g1 starts with a small diameter through hole, the first through hole of the next plate-shaped vane belonging to the second plate-shaped vane group 52g2 is arranged to have a large diameter through hole, and the first through hole of the next plate-shaped vane belonging to the first plate-shaped vane group 52g1 is arranged to have a small diameter through hole, and this is repeated alternately.

[0039] Similarly, the size of the second through hole in the first plate-shaped vane group 52g1 and the second plate-shaped vane group 52g2 is such that if the second through hole of a plate-shaped vane belonging to the first plate-shaped vane group starts with a large diameter through hole, the second through hole of the next plate-shaped vane belonging to the second plate-shaped vane group 52g2 is arranged to have a small diameter through hole, and the second through hole of the next plate-shaped vane belonging to the first plate-shaped vane group 52g1 is arranged to have a large diameter through hole, and this is repeated alternately.

[0040] The third through hole is the same as the first through hole. Each of the equalizing rings 64 contacts the plate-shaped vane in the through hole with a small area, and does not contact the plate-shaped vane in the through hole with a large area. Note that, although the shape of the through hole is described as being circular in the present invention, it is not necessary that it be circular.

[0041] (Regarding the second issue) In this embodiment, the second problem, i.e., suppressing the effect of unnecessary radiation on the fundamental wave, is solved by using three or more equalizing rings 64. The reason for using three or more equalizing rings 64 will be explained with reference to FIG. 6.

[0042] Fig. 6 is a diagram showing the correlation between the strap ratio and unwanted radiation. The purpose of the pressure equalizing ring 64 is to equalize the potential of the plate-shaped vanes 52 and to suppress the influence of unwanted radiation that becomes noise. Fig. 6 shows a plate-shaped vane arrangement 6A, an enlarged view 6B of part B of the plate-shaped vane arrangement 6A, a relational expression 6C of the strap ratio, and an example of a spectrum 6D.

[0043] The inventors have confirmed that the influence of unwanted radiation cannot be sufficiently suppressed with a configuration in which there are two equalizing rings 64 in the high-output magnetron 100. Therefore, in this embodiment, three or more equalizing rings are used.

[0044] In detail, the magnetron 100 resonates in the resonant cavity formed by the inner wall surface of the anode cylinder 53 and each of the plate-like vanes 52, and generates a fundamental wave having a resonant frequency. However, at the same time, unwanted radiation that adversely affects the fundamental wave is also generated. If the unwanted radiation is close to the oscillation frequency of the fundamental wave, the influence of the unwanted radiation on the fundamental wave cannot be suppressed completely, which may cause abnormal oscillation and cause the magnetron to stop oscillating.

[0045] To be more specific, in the case of a low-output magnetron with an output of about 2kW, such as a household magnetron or an industrial magnetron with an output of 2 to 10kW, even if unwanted radiation is emitted, the output is not large, so the likelihood of it causing abnormal emissions is quite low. However, in the case of a high-output magnetron of, for example, a 15kW class, the effects of unwanted radiation cannot be ignored.

[0046] In order to suppress unwanted radiation, it is necessary to reduce the influence of the unwanted radiation, which is in a frequency band close to the oscillation frequency of the fundamental wave, by separating it as greatly as possible from the oscillation frequency of the fundamental wave.

[0047] It is known that increasing the strap ratio is effective in dissociating unwanted radiation. Using the calculation formula for the strap ratio shown in Figure 6, the strap ratio can be increased by increasing the capacitance Cs formed by the gap between the equalizing ring and the vane where the equalizing ring is not in contact, as shown in the enlarged view of part B in Figure 6. In other words, the effect of unwanted radiation on the fundamental wave can be eliminated.

[0048] In order to suppress the influence of unwanted radiation on the fundamental wave in a high-output magnetron with an output of 15 kW or more, the inventors decided to increase the Cs content by using at least three or more pressure equalizing rings 64. Test operations are performed during the manufacturing stage of the magnetron, and the number of through holes and pressure equalizing rings is set to increase the separation between the oscillation frequency of the fundamental wave and the unwanted radiation so that the unwanted radiation does not affect the fundamental wave.

[0049] Fig. 7 is a diagram showing the effect of three equalizing rings 64. In order to confirm the effect of this embodiment, the inventors verified the generation state of unwanted radiation using a configuration with two equalizing rings 64 and a configuration with three equalizing rings 64. In Fig. 7, the result for the two equalizing rings 64 is R72, and the result for the three equalizing rings 64 is R73.

[0050] In the case of result R72, the fundamental wave is 2.46 GHz while the unwanted radiation is 3.16 GHz, and the frequency difference with the fundamental wave is 0.7 GHz. In contrast, in the case of result R73, the fundamental wave is 2.38 GHz while the unwanted radiation is 3.23 GHz, and the frequency difference with the fundamental wave is 0.85 GHz. In the case of result R73, compared to result R72, the unwanted radiation, which has a frequency close to the oscillation frequency of the fundamental wave, is moved as far away from the fundamental wave as possible, thereby suppressing the impact on communication equipment that uses the fundamental frequency.

[0051] As shown in the diagram of the effect of three equalizing rings in Figure 7, with two equalizing rings, unwanted radiation of large amplitude occurred around 3.2 GHz, causing the magnetron to stop oscillating. When the equalizing rings were configured with three rings, the unwanted radiation around 3.2 GHz was significantly reduced, and the effect on the fundamental wave was suppressed.

[0052] FIG. 8 is a diagram showing the connection between the strain equalizing rings. The connection between the strain equalizing rings will be explained using the diagram showing the connection between the strain equalizing rings in FIG. 8. By increasing the uniformity of the potential between the nth strain equalizing rings and the n+1th strain equalizing rings, it is possible to more effectively suppress the occurrence of abnormal oscillation. As shown in FIG. 8, it is preferable to connect the nth strain equalizing rings to each other at a predetermined position of the strain equalizing ring, and to connect the n+1th strain equalizing rings to each other at a predetermined position of the strain equalizing ring.

[0053] As described above, the magnetron 100 of this embodiment has the following features. (1) The magnetron 100 is a high-power industrial magnetron comprising an anode cylinder 53, a plurality of plate-shaped vanes 52, one end of which is fixed to a plurality of different fixing portions 52f on the inner wall surface of the anode cylinder 53 and the other end of which extends from the fixing portion 52f toward the central axis of the magnetron, and a predetermined number of pressure equalizing rings 64 arranged inside the anode cylinder 53. The plurality of plate-shaped vanes 52 form a first plate-shaped vane group 52g1 consisting of a collection of plate-shaped vanes spaced in a row clockwise or counterclockwise starting from a plate-shaped vane at a predetermined position, and a second plate-shaped vane group 52g2 consisting of a collection of plate-shaped vanes excluding the first plate-shaped vane group 52g1.

[0054] All the plate-shaped vanes 52 belonging to the first plate-shaped vane group 52g1 and all the plate-shaped vanes 52 belonging to the second plate-shaped vane group 52g2 have the same number of through holes 52h, at least three or more, near the tip in the direction of the central axis, and penetrate the nth pressure equalizing ring 64_n so as to contact the nth through hole 52hn of all the plate-shaped vanes belonging to the first plate-shaped vane group 52g1, and penetrate the n+1th pressure equalizing ring 64_n+1 so as to contact the n+1th through hole 52gn+1 of all the plate-shaped vanes belonging to the second plate-shaped vane group 52g2, where n is an odd number starting with 1. This prevents damage to the choke coil 81 and suppresses oscillation stop due to the occurrence of abnormal oscillation.

[0055] (2) In the magnetron 100 of (1) above, the nth through holes 52hn of all plate-shaped vanes belonging to the first plate-shaped vane group 52g1 have a congruent shape, the n+1th through holes 52hn+1 of all plate-shaped vanes belonging to the second plate-shaped vane group 52g2 have a congruent shape, and the nth through holes 52hn and the n+1th through holes 52hn+1 have different areas (see Figures 4 and 5).

[0056] (3) The magnetron 100 of (1) is characterized in that the nth stress equalizing ring 64_n does not contact the nth through hole 52hn of any of the plate-shaped vanes belonging to the second plate-shaped vane group 52g2, and the n+1th stress equalizing ring 64_n+1 does not contact the n+1th through hole 52hn+1 of any of the plate-shaped vanes belonging to the first plate-shaped vane group 52g1 (see Figure 5).

[0057] (4) The magnetron of (1) above, characterized in that the n-th stress equalizing rings 64_n are connected to each other at predetermined positions of the stress equalizing rings, and the n+1-th stress equalizing rings 64_n+1 are connected to each other at predetermined positions of the stress equalizing rings (see FIG. 8).

[0058] (5) The magnetron 100 of (1) is characterized in that a test operation is performed during the manufacturing stage of the magnetron, and the number of through holes 52h and pressure-equalizing rings 64 is set so as to widen the separation between the fundamental wave generated by resonance in the resonant cavity and the unwanted radiation (see FIG. 7). As described above, in FIG. 7, with the specification of two pressure-equalizing rings, unwanted radiation of large amplitude occurs near 3.2 GHz, and the magnetron stops oscillating. When the pressure-equalizing rings are configured with three, the unwanted radiation near 3.2 GHz is greatly reduced, and the effect on the fundamental wave is suppressed.

[0059] The present invention is not limited to the above-described embodiment, but includes various modified examples. The above-described embodiment has been described in detail to clearly explain the present invention, and the present invention is not necessarily limited to those including all of the configurations described. It is also possible to add, delete, or replace part of the configuration of each embodiment with other configurations. [Explanation of symbols]

[0060] 51 Cathode filament 52 Plate-shaped vein 52h through hole 52g1 First plate-shaped vein group 52g2 Second plate-shaped vein group 52f Fixed part 53 Anode Cylinder 54,54a Permanent magnet 55,55a magnetic pole 56,56a York 57 Antenna Lead 58 Antenna Block 59 Vacuum tube 61 Output side ceramic 63 Working space 64 Strap ring 66,67 Upper and lower sealing metal 68,68a Upper and lower anode plates 69 Output section 70 Magnetic circuit section 71 Upper end shield 72 Lower end shield 73 Cathode lead (center lead) 74 Cathode lead (side lead) 75 Input side ceramic 76 Terminal board 77 Cooling mechanism 77a Cooling water passage 78 Cathode 79 Anode 80 Exhaust pipe 81 Choke coil (coil) 82 Feedthrough capacitor 83 Filter Case 84 Lid 85 Filter Structure 100 Magnetron

Claims

1. A high-power industrial magnetron, an anode cylinder; a plurality of plate-shaped vanes each having one end fixed to a plurality of different fixing portions on the inner wall surface of the anode cylinder and having the other end extending from the fixing portion toward the central axis of the magnetron; A predetermined number of equalizing rings are disposed inside the anode cylindrical body, The plurality of plate-shaped vanes are arranged in a first plate-shaped vane group consisting of a set of the plate-shaped vanes arranged in a clockwise or counterclockwise direction starting from a plate-shaped vane at a predetermined position, and a second plate-shaped vane group consisting of a set of the plate-shaped vanes excluding the first plate-shaped vane group; All of the plate-like vanes belonging to the first plate-like vane group and all of the plate-like vanes belonging to the second plate-like vane group have an equal number of through holes, at least three or more, near their tips in the direction of the central axis, the n-th through hole of all the plate-shaped vanes belonging to the first plate-shaped vane group is penetrated through the n-th pressure equalizing ring so as to contact the n-th through hole of all the plate-shaped vanes belonging to the first plate-shaped vane group, The n+1-th pressure equalizing ring is penetrated so as to contact the n+1-th through hole of all the plate-shaped vanes belonging to the second plate-shaped vane group. A magnetron characterized by:

2. 2. The magnetron of claim 1, The n-th through holes of all the plate-shaped vanes belonging to the first plate-shaped vane group have a congruent shape, The (n+1)-th through holes of all the plate-shaped vanes belonging to the second plate-shaped vane group have a congruent shape, The n-th through hole and the n+1-th through hole have different areas. A magnetron characterized by:

3. 2. The magnetron of claim 1, the n-th pressure equalizing ring does not contact the n-th through hole of any of the plate-like vanes belonging to the second plate-like vane group; The (n+1)th pressure equalizing ring does not contact the (n+1)th through hole of any of the plate-shaped vanes belonging to the first plate-shaped vane group. A magnetron characterized by:

4. 2. The magnetron of claim 1, The n-th equalizing rings are connected to each other at predetermined positions of the equalizing rings, The (n+1)th equalizing rings are connected to each other at predetermined positions of the equalizing rings. A magnetron characterized by:

5. 2. The magnetron of claim 1, A magnetron characterized in that a test operation is performed during the manufacturing stage of the magnetron, and the number of the through holes and the equalizing rings is set so as to widen the separation between the fundamental wave generated by resonance in the resonant cavity and unnecessary radiation.

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