JPH11250818A - Magnetron - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress radiation of spurious waves in a low frequency range by constituting an output antenna with a plurality of antenna constituting parts divided and connecting the constituting parts through an insulator. SOLUTION: An insulator 21 is interposed between a first antenna constituting part 19 and a second antenna constituting part 20 for constituting an output antenna 18 to constitute a by-pass filter. Electric wave oscillated with a cavity resonator comprising adjacent vanes 2 and the inner surface of a positive electrode cylinder 1 between the vanes 2 is propagated to the first antenna- constituting part 19. The electric wave in a high frequency range containing the fundamental wave is passed through the insulator 21 without attenuation, passed through the second antenna-constituting part 20, then radiated, but the electric wave in the low frequency range lower than the fundamental wave is attenuated with the by-pass filter constituted of the insulator 21, and noise is substantially reduced. Since the first and second antenna constituting parts 19, 20 are handled as one component through the insulator 21, the alternation, in the assembling device is unnecessary.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a magnetron used for a microwave oven or the like.

[0002]

2. Description of the Related Art A magnetron of this kind is 2450 MHz.
However, unnecessary radio waves in a wide frequency band from low frequency band noise to harmonic noise are also radiated, and there is a possibility that communication equipment, broadcasting equipment and the like may be disturbed.

In order to suppress the emission of unnecessary radio waves, for example, as shown in Japanese Patent Publication No. 5-68823, a quarter of the frequency to be suppressed is formed coaxially with the output antenna.
Although a technique for providing a choke structure having a wavelength length has been proposed, it can cope with suppression of a high frequency band that can make the size of the choke structure relatively small, but in order to suppress unnecessary radio waves in a low frequency band. However, the size of the chalk structure was large and it was difficult to incorporate it into the magnetron.

[0004]

SUMMARY OF THE INVENTION The present invention has been made in consideration of the above problems, and has as its object to provide a magnetron capable of suppressing the emission of unnecessary radio waves in a low frequency band.

[0005]

A first means of the present invention is as follows.
An anode cylinder provided with a plurality of vanes toward the center, a cathode disposed at the center of the anode cylinder, and an output antenna connected to the vane and extending to an output portion, Dividing the output antenna into a plurality of antenna components,
The antenna components are connected via an insulator.

According to a second aspect of the present invention, there is provided an anode cylinder having a plurality of vanes disposed toward the center, a cathode disposed at the center of the anode cylinder, and an output section connected to the vane. And an output antenna extending to the, wherein the output antenna,
A first antenna component connected to the vane, and a second antenna component connected to the output portion, wherein the first antenna component and the second antenna component are connected via an insulator. And connected.

According to a third aspect of the present invention, there is provided an anode cylinder having a plurality of vanes disposed toward the center, a cathode disposed at the center of the anode cylinder, and an output section connected to the vane. And an output antenna extending to the, wherein the output antenna,
In addition to being divided into a plurality of antenna components, a flat plate is formed at a position opposite to the antenna component, and the flat plates are connected to each other via an insulator.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below in detail with reference to FIG.

Reference numeral 1 denotes an anode cylinder, and a plurality of vanes 2 are disposed toward the center. A pair of strap rings 3 and 4 are connected to the vanes 2 every other one. Reference numeral 5 denotes a cathode disposed in a working space surrounded by the center vane 2 of the anode cylinder 1, and end shields 6, 7 are fixed to upper and lower ends thereof. The end shields 6, 7 are supported by cathode supports 8, 9, respectively.
Are fixed to a cathode stem 17 described later.

Reference numeral 10 denotes an output pole piece disposed at the output end of the anode cylinder 1, and reference numeral 11 denotes an output fixed to the output end of the anode cylinder 1 so as to cover the output pole piece 10. A side sealing metal, 12 is an insulating cylinder fixed to the end of the output side sealing metal 11, and 13 is an exhaust pipe fixed to an end of the insulating cylinder 12, which is sealed off together with an output antenna 18 described later. Is done. Reference numeral 14 denotes a covering cylinder that covers the end of the exhaust pipe 13.

Reference numeral 15 denotes an input pole piece disposed at the input end of the anode cylinder 1, and 16 denotes an input fixed to the input end of the anode cylinder 1 so as to cover the input pole piece 15. A side sealing metal 17 is a cathode stem fixed to an end of the input side sealing metal 16 and supports a cathode support *.

An output antenna 18 has a first antenna component 19 having one end fixed to one of the vanes 2, a second antenna component 20 having one end sealed off together with the exhaust pipe 13, An insulator 21 disposed between the other end of the first antenna component 19 and the other end of the second antenna component 20 for connecting the first antenna component 19 and the second antenna component 20; And an insulator 2 between the first antenna component 19 and the second antenna component 20.
By interposing 1, a so-called high-pass filter is constituted by the insulator 21. The insulator 21
In this embodiment, alumina ceramics is used.

The radio wave oscillated by the cavity consisting of the adjacent vanes 2 and the inner surface of the anode cylinder 1 between them propagates to the first antenna component 19. Radio waves in the high frequency band including the fundamental wave pass through the insulator 21 without attenuation, and are radiated through the second antenna component 20. And the noise is greatly reduced.

Since the first antenna component 19 and the second antenna component 20 are connected via the insulator 21, they can be handled as one component as in the conventional case, and assembled in the conventional manner. Therefore, it is not necessary to change the assembling apparatus and the like.

FIG. 2 shows another embodiment of the present invention, in which an output antenna 22 includes three antenna components 23, 24,
25, and an insulator 26 interposed between the antenna components 23 and 24 and between the antenna components 24 and 25 to connect them.

FIG. 3 shows still another embodiment of the present invention, in which a disk-shaped first antenna component 28 and a second antenna component 29 constituting an output antenna 27 are respectively provided. The coupling portions 30 and 31 are formed, and an insulator 32 is interposed between the coupling portions 30 and 31.

The embodiment shown in FIGS. 2 and 3 can attenuate radio waves in a low frequency band and reduce noise as in the embodiment shown in FIG.

In the above embodiments, no measures are taken to reduce noise in the high frequency band. However, if necessary, conventional techniques can be used as needed to further reduce noise. Can be.

[0019]

As described above, according to the configuration of the first aspect of the present invention, it is possible to suppress the emission of unnecessary radio waves in the low frequency band without affecting the emission of the fundamental wave. Play.

According to the configuration of the second aspect of the present invention, it is possible to suppress the radiation of unnecessary radio waves in the low frequency band without affecting the radiation of the fundamental wave.

According to the configuration of the third aspect of the present invention, it is possible to suppress radiation of unnecessary radio waves in a low frequency band without affecting radiation of a fundamental wave.

[Brief description of the drawings]

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

FIG. 2 is a cross-sectional view of a main part showing another embodiment of the present invention.

FIG. 3 is a cross-sectional view of a main part showing still another embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Anode cylinder 2 Bain 5 Cathode 18 Output antenna 19 First antenna component 20 Second antenna component 21 Insulator 22 Output antenna 23 Antenna component 24 Antenna component 25 Antenna component 26 Insulator 27 Output antenna 28 Antenna component part 29 Antenna component part 30 Coupling part 31 Coupling part 32 Insulator

Claims (3)

[Claims] 1. An anode cylinder having a plurality of vanes disposed toward the center, a cathode disposed at the center of the anode cylinder, and an output antenna connected to the vanes and extending to an output section. Wherein the output antenna is divided into a plurality of antenna components, and the antenna components are connected via an insulator. 2. An anode cylinder having a plurality of vanes disposed toward the center, a cathode disposed at the center of the anode cylinder, and an output antenna connected to the vanes and extending to an output section. And wherein the output antenna comprises a first antenna component connected to a vane, and a second antenna component connected to an output unit, wherein the first antenna component and a second antenna A magnetron wherein an antenna component is connected via an insulator. 3. An anode cylinder having a plurality of vanes disposed toward the center, a cathode disposed at the center of the anode cylinder, and an output antenna connected to the vanes and extending to an output section. The output antenna is divided into a plurality of antenna components, and a flat plate portion is formed at a position opposite to the antenna component portion, and the flat plate portions are connected via an insulator. A featured magnetron.