KR920010656B1 - Magnetron having function of electromagnetic wave leakage - Google Patents

Abstract

No content.

Description

Magnetron with function to block leakage of electromagnetic waves

1 is a side sectional view showing a main part of a magnetron according to a first embodiment of the present invention;

2 is a perspective view showing a ring-shaped metal piece of the magnetron of FIG.

3 is a side sectional view showing a main part of a second embodiment of the present invention;

4 is a partial perspective view showing a part of a metal piece according to the third embodiment.

5 is a partial perspective view showing a part of a ring-shaped metal piece according to a third embodiment of the present invention.

* Explanation of symbols for the main parts of the drawings

1: anode cylinder 2: cathode

3: bipolar vane 4, 5: magnetic pole piece

6: exhaust pipe 7: insulated pipe

8, 14 metal tube 9: microwave induction conductor

12: metal plate 13a, 13b, 13c, 13d, 15a, 15b: slot

14a: metal plate

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetron used in microwave heating equipment such as a microwave oven, and more particularly to a magnetron having a function of blocking leakage of electromagnetic waves.

In general, a magnetron used in a microwave oven or the like is configured as shown in FIG. 6, and the cylindrical anode cylinder 1 includes a plurality of anodes which protrude toward the cathode 2 to form a resonant cavity. On the inner circumferential surface of the vane 3, first and second magnetic pole pieces 4 and 5 for magnetic field regeneration having funnel shapes are arranged so as to face each other at both open ends of the anode cylinder 1. have. And the flange part 8a of the eyelet-shaped metal pipe 8 sealed with the metal exhaust pipe 6 via the ceramic insulating pipe 7 covered the 1st magnetic pole piece 4 The microwave extraction conductor 9 extending from the anode vane 3 is sealed to the open end of the anode cylinder 1 and connected to the exhaust pipe 6. In addition, the exhaust pipe 6 is covered with a microwave output terminal 10 having a cap shape made of metal. Although not shown in the drawing, another eyelet-shaped metal tube 11 adhered to the other opening end of the anode cylinder 1 in a state where the second pole piece 5 is covered with a flange is omitted. The stem of the dragon is sealed.

The magnetron oscillates a microwave having a fundamental wave of 2450 MHz, and its output is drawn from the microwave output terminal 10. The microwave output includes a fundamental wave component and a harmonic component having a frequency of an integer multiple thereof. In particular, it is not easy to seal higher harmonic components, and leakage of such harmonic components to the outside of the apparatus may cause undesirable effects such as communication interference. Therefore, as disclosed in Japanese Patent Application Laid-Open No. 56-21215, a choke member for blocking harmonic components is provided in the microwave conductor.

However, when the cylindrical choke member is sealed in the pipe, a large space must be secured in the pipe, so that the magnetron cannot be formed in a simple structure.

The present invention, in order to solve the above-mentioned problems, the anode vane protruding toward the cathode from the inner circumferential surface of the anode cylinder by attaching and sealing a metal exhaust pipe through a metal tube and an insulated tube at one open end of the anode cylinder ( In a magnetron formed by connecting a microwave conducting conductor extending from vane) to the exhaust pipe, a ring-shaped metal plate portion surrounding the microwave conducting conductor is provided in the metal tube, and a part of the oscillating microwave A slot of an electric field corresponding to about one quarter wavelength or about one half wavelength of harmonic components of any order is formed.

In this configuration, since the choke of the micro strip line type is constituted by the metal plate part, the harmonic component radiated to the outside of the tube using the microwave conducting conductor as a propagation path is formed in the metal plate part. Since resonance is attenuated or reflected in the slot of, the amount of radiation leaking to the outside of the tube can be reduced.

Next, an embodiment of the present invention will be described in detail with reference to the drawings. The difference between the configuration according to the embodiment of the present invention shown in FIG. 1 and the conventional configuration shown in FIG. 6 is that the ring-shaped metal plate 12 surrounding the microwave conducting conductor 9 is in the eyelet shape. It is a point attached to the neck part of the metal plate 8, and except for this, all have the same structure. That is, as shown in FIG. 2, the metal plate 12 has four slots 13a, 13b, 13c, and 13d. For example, the slot 13a has a second shape. It has an electric field La corresponding to about one quarter wavelength of the harmonic component, and the slot 13b has an electric field Lb corresponding to one quarter wavelength of the third harmonic component, and in the same manner Each slot has an electric field that corresponds to about a quarter of the other harmonics. Although the electric field is slightly influenced by the central hole 13 of the metal plate 12, the electric field is formed in such a configuration, so that it is possible to include a plurality of microstrip line type chokes.

The metal plate 12 does not need to be formed of a single member. In the embodiment as shown in FIG. 3, the ring-shaped metal plate portion 14a is formed in the cross section itself of the small diameter of the eyelet-shaped metal tube 14, and the metal plate portion 14a as shown in FIG. ), A central hole 15 and a suitable number of slots 15a and 15b are formed.

In the embodiment as shown in FIG. 5, the tubular portion 14b is formed at the edges around the center hole of the metal plate portion 14a, and the tubular portion 14b is approximately approximately harmonics of any order. As a quarter wavelength electric field, the choke which cuts the radiation of the said harmonic is formed.

In the magnetron configured as described above, one or more kinds of harmonic components can be attenuated by about 40 dB by the metal plate portion 14a of the metal plate 12 or the metal tube 14, respectively. By arranging in, more harmonic components can be attenuated. Of course, you may form the electric field of each slot.

As described above, according to the present invention, by simply forming a ring-shaped metal plate portion on the output side of a conventional metal tube, the length of the axial direction can be shortened by producing a magnetron having a plurality of types of flat choke action portions. Can also reduce costs.

Claims (4)

A metal exhaust pipe 6 is sealed at one opening end of the anode cylinder 1 via a metal tube 8 and an insulated tube 7, and is moved from the inner circumferential surface of the anode cylinder 1 toward the cathode 2. In the magnetron formed by connecting a microwave-derived conductor 9 extending from the protruding anode vane 3 to the exhaust pipe 6, the microwave-conducting conductor 9 is attached to the metal tubes 8 and 14. Is formed in the shape of an arc along the periphery of the metal plates 12 and 14a, in which ring-shaped metal pieces 12 and 14a enclosing) are placed and resonate with harmonic components of any order of the oscillated microwave. To prevent leakage of electromagnetic waves by forming slots 13a, 13b, 13c, 13d, and 15a and 15b in a plane perpendicular to the observation of the metal pieces 12 and 14a. Branches magnetron. 2. A slot according to claim 1, wherein the slots (13a) (13b) (13c) (13d) and (15a) (15b) correspond to one-quarter or one-half wavelengths of the harmonic components of any order. Magnetron having the function of blocking the leakage of electromagnetic waves by forming an electric field. The magnetron according to claim 1, wherein the slots (13a) (13b) (13c) (13d) and (15a) (15b) have a function of blocking the leakage of electromagnetic waves by being made of a plurality of electric fields different from each other. 2. The magnetron according to claim 1, wherein the metal piece (14a) is formed in the same body as the ring-shaped metal pipe (14) to block leakage of electromagnetic waves.