KR19990012806A - Operation Method of Microwave Oscillator for Microwave Oven - Google Patents

Abstract

The present invention relates to a method of operating a microwave oven tube for microwave oven, the method comprising the steps of controlling and focusing the hot electrons emitted from the cathode to the bias voltage of the first grid, and the electron beam by the potential difference between the first grid and the second grid Accelerating, decelerating the electron beam between the second grid and the anode, inducing surface current in the output cavity to generate microwaves, feeding back a portion of the microwave to the input cavity, and outputting high frequency power It is characterized by consisting of the step of transmitting and radiating from the cavity to the antenna.

The microwave oven employing the ultra-high frequency oscillation tube according to the present invention is not only ensures stability against high pressures compared to conventional klystrons, but also requires no high voltage circuit portion compared to conventional magnetrons, thereby achieving light weight, and the first and the second. By using the grid to focus the electron beam, the magnet for external magnetic field becomes unnecessary, and the cathode, the first and the second grid, and the anode form a planar structure, which simplifies the structure and achieves light weight, and the auto bias of the first grid. The function eliminates the need for a separate bias power supply from the outside, making the product inexpensive.

Description

Operation Method of Microwave Oscillator for Microwave Oven

The present invention relates to an ultra-high frequency oscillation tube for a microwave oven, and more particularly, to a method of operating a microwave high-frequency oscillation tube that can achieve a weight reduction and a risk due to its simple structure.

As is well known, a microwave oven employs, for example, a magnetron driven at a high voltage of 4 KV as an ultra high frequency oscillation tube. Such a magnetron is a kind of two-pole vacuum tube that generates microwaves. As shown in FIG. 1, when electric power is applied to an input unit consisting of a condenser 11, a coil 12, and the like, hot electrons emitted from the filament of the cathode 1 are generated. The electric field is formed in the working space 4 between the ends of the plurality of vanes 3 and the filament extending on the inner wall of the cylindrical anode 2. In addition, a magnetic field is applied to the working space 4 by a magnetic circuit composed of a magnet 5 and a magnetic pole 6 so that hot electrons undergo a cycloid movement, and the energy of the movement is taken into the vane 3 and the strap 8. ) Is radiated to the cooking chamber through an antenna 7 connected to the vane 3, and an output portion composed of the A ceramic 9, the A seal 10, and the like.

2, when the magnetron emits hot electrons from the cathode 1, the electrons are accelerated under the influence of the electric field and the magnetic field, and move to the anode 2 while making the pivoting movement. A high frequency current is formed on the surface of 2), and the resonance frequency is determined by the L and C values acting between the vanes 3, so as to generate microwaves when a predetermined resonance condition is satisfied.

However, such a conventional magnetron for a microwave oven requires a high voltage transformer and a high pressure diode according to a high pressure driving, so there is a problem in safety, and a magnet is required because it adopts a resonance method by electromagnetic movement in an electromagnetic field. This was heavy and expensive to manufacture.

To solve this problem, FIG. 3 illustrates a Klystron employed as a microwave high frequency oscillation tube disclosed in US Pat. No. 5,541,391. As shown in the figure, the chrystron 40 includes an input terminal 42 for receiving power, a klystron body 41 for generating microwaves in response to the supply of power to the input terminal 42, and a klystron body. An antenna 32 for transmitting microwaves from the 41, a cooling unit 43 for dissipating heat generated in the chrysron body 41 to the outside, and an electron beam concentrator 49 provided to receive electrons. The cooling unit 43 supports the cooling fins 44 and the cooling fins 44 arranged to dissipate heat generated by the reception of electrons, and heat from the electron beam concentrator 49. It consists of a cooling rod 46 and a closing body 48 surrounding the cooling fin 44 arranged to deliver to the cooling fin 44.

The klystron 40 also receives a power supply via the input terminal 42, and a pair of electron guns 50, which generate electrons by the received power supply, and a pair of electron guns 50 and the electron beam concentrator 49, respectively. The magnet 52, the yoke 54 which acts as a guide | route which comprises the closed loop by this magnet 52, and the tube 56 interposed between the magnet 52 with the some cavity is included.

As shown in FIG. 4, the klystron is hot electrons emitted from the cathode 60 heated by the heater 58 and the potential difference between the cathode 60 and the anode 62 with the modulating member 70 interposed therebetween. Accelerated by a plurality of cavities 64, 66, 68, and induce surface currents in each cavity by electron beams passing through the cavities, and generate microwaves at resonance frequencies corresponding to the shapes of the cavities. After converting the kinetic energy of the electrons into microwave energy, high frequency power is transmitted from the final cavity 66 to the antenna 32.

However, microwave ovens employing Klystron still apply high voltage, so the input terminals must be insulated from the Klystron body with a separate insulation member, resulting in heavy product, complicated electronic motion, complicated cooling structure, and many It must be a structure having a cavity of, and a magnet is required because the electron beam focusing structure is required, and the structure has a disadvantage in that the structure is complicated.

Accordingly, the present invention is to provide a method of operating a microwave oven tube for microwave oven that is simple in structure and can eliminate the risk due to high voltage and achieve light weight.

As a means for achieving the above object, the operating method of the microwave microwave oscillation tube of the present invention comprises the steps of controlling and focusing the hot electrons emitted from the cathode to the bias voltage of the first grid, and the first grid and the second Accelerating the electron beam by the potential difference of the grid, decelerating the electron beam between the second grid and the anode and inducing a surface current in the output cavity to feed a microwave, and feeding back a portion of the microwave to the input cavity And supplying and radiating ultra-high frequency power from the output cavity to the antenna.

1 is a schematic cross-sectional view showing the structure of a magnetron used as a conventional microwave microwave tube.

Figure 2 is a schematic diagram showing the operation principle of the magnetron of Figure 1,

3 is a schematic cross-sectional view showing the structure of Klystron used as a conventional microwave microwave tube.

4 is a schematic diagram showing the operation principle of the klystron of FIG.

5 is a cross-sectional view showing the structure of the microwave oven for microwave oven of the present invention,

6 is a schematic diagram showing the operation principle of the ultra-high frequency oscillation tube of FIG.

Explanation of symbols on the main parts of the drawings

100: high frequency oscillation tube 102: bracket

104: filter box cover 110: power input unit

120: heater 130: input cavity

132: cathode 134: first grid

136: choke structure 140: output cavity

142: second grid 146: anode

148 cooling pin 150 antenna

152: coupling end 160: feedback rod

Hereinafter, with reference to the accompanying drawings will be described in detail the operation method of the microwave microwave oscillation tube for a preferred embodiment of the present invention.

Microwave oscillation tube for microwave oven of the present invention, as shown in Figure 5, the power input unit 110, the heater 120, the input cavity 130 in the filter box 105 is covered with a cover 104 in the lower portion ), An output cavity 140, and a feedback rod 160 are provided, and the antenna 150 in the anode 146 is installed in the bracket 102. The inside of the filter box 105 and the part of the antenna 150 of the anode 146 maintain a vacuum, and the input cavity 130 is a space surrounded by the cathode 132, the first grid 134, and the choke structure. The output cavity 140 is a space surrounded by the second grid 142 and the anode 146 in which the cooling fin 148 is installed, and the coupling end 152 is attached to the end of the antenna 150. Since the configuration is described in detail in Patent Application No. 97- filed as the same as the present application, it is omitted for convenience of description, and the operation method will be described in detail below with reference to FIG.

Operation of the microwave microwave tube 100 for the microwave according to the present invention first emits hot electrons by an indirect heating method of heating the cathode 132, which is an electron radiator, by the heat of the heater 120 composed of an annular filament. That is, when the cathode 132 mounted on the upper surface of the heater 120 is heated to about 600-1200 ° C. by the heat of the heater 120, the electrons are emitted.

Subsequently, when a bias voltage is applied to the first grid 134 arranged at predetermined intervals above the disk-shaped cathode 132, electrons emitted from the cathode 132 are controlled and focused on the input cavity 130.

When the electrons focused on the input cavity 130 are densely modulated by the automatic shielding function of the bias power supply of the first grid 132, the operating power is applied between the input / output cavities 130 and 140 insulated from each other. A potential difference is generated between the first and second grids 132 and 142 to accelerate the electron beam passing through the first grid 132.

Thereafter, the accelerated electron beam is decelerated between the second grid 142 and the anode 140, so that surface current is induced in the anode 146 of the output cavity 140, so that microwaves are generated in the output cavity 140. .

At this time, a part of the generated microwave is fed back to the input cavity 140 by the feedback rod 160 formed between the input and output cavities 130 and 140 to amplify and resonate the power of the microwave.

Finally, the ultra-high frequency power generated in the output cavity 140 is coupled to the coupling end 152 extending in the output cavity 140 and radiated through the antenna 150.

According to the present invention, compared to a conventional microwave oven, the structure is simple and the stability to high pressure is not only ensured, and since the high voltage circuit unit is not required compared to a conventional microwave oven using a conventional magnetron, weight reduction is achieved. And a second grid to focus the electron beam, thereby eliminating the need for an external magnetic field magnet, and forming a planar structure of the cathode, the first and second grids, and the anode, thereby simplifying the structure and reducing the weight. Auto bias function eliminates the need for a separate bias power supply from the outside, reducing the cost of the product.

Claims (5)

In the operation method of the microwave oven tube for microwave, Controlling and focusing the hot electrons emitted from the cathode to the bias voltage of the first grid, Accelerating the electron beam by the potential difference between the first grid and the second grid; Slowing the electron beam between the second grid and the anode and inducing a surface current in the output cavity to generate microwaves; Feeding back a portion of the microwave to an input cavity; A method of operating a microwave oven for microwave ovens, characterized in that the step consisting of transmitting the ultra-high frequency power from the output cavity to the antenna. 2. The method according to claim 1, wherein density modulating the electrons accumulated in the input cavity is performed by an automatic shielding function of the bias power supply of the first grid. The method of operating a microwave oven for microwave oven according to claim 1, wherein the inside of the microwave oven maintains a vacuum. The microwave oven according to claim 1, wherein the feedback means feeds back a portion of the microwaves formed in the output cavity to the input cavity using a feedback rod formed at the center of the cavities to amplify and resonate the power of the microwave. Operation method of high frequency oscillator tube. The method according to claim 1, wherein the input / output cavities are insulated from each other, and the distance therebetween maintains a distance of several tens to hundreds of microns.