KR100398966B1 - Ultra High Frequency Oscillator - Google Patents

Abstract

The present invention relates to an ultra-high frequency oscillation apparatus, and includes driving power generation means for outputting an input voltage at a voltage of a predetermined level, and a power input portion for receiving low voltage output power provided from the driving power generation means. The heat generating means generates heat by receiving power supplied from the power input unit. The input cavity is a space surrounded by cathodes sequentially installed on the heat generating means, a first grid provided at a predetermined interval on the cathode, and a choke structure for insulating the first grid and the cathode. Heated to a predetermined operating temperature by the heat of the heat generating means to emit hot electrons, the first grid is applied a bias voltage to control and focus the electrons emitted from the cathode, the choke structure is inside the input cavity The surface current forming the microwaves is energized, and the direct current between the cathode and the first grid is shielded. The output cavity is a space surrounded by a second grid arranged on top of the first grid and an anode formed on the second grid and formed corresponding to the cathode, wherein the anode includes a plurality of cooling fins to cool heat. The stacked array extinguishes the decelerated electron beam, and the second grid induces a surface current while electrons passing through the first grid of the input cavity pass, and densely modulates the electrons focused on the input cavity. Microwaves are formed by the surface current induced in the second grid and accelerated by the potential difference between the first grid and the second grid. Radiating means for radiating microwaves is formed in the output cavity. The feedback means is for feeding back a part of the microwaves formed in the output cavity from the output cavity into the input cavity, the directional coupler for separating a part of the output power generated from the output cavity, and a part of the separated output power. An attenuator for accurately reducing the amount of power required, a phase adjuster for precisely adjusting the phase of the power attenuated by the attenuator, and a position corresponding to the output cavity in the input cavity, A part of the output power radiated is composed of a feedback rod which is adjusted to the same phase as the output power and fed back.

Description

Ultra High Frequency Oscillator

The present invention relates to an ultra-high frequency oscillation apparatus, and more particularly to an ultra-high frequency oscillation apparatus having an external feedback structure.

In general, a heat transfer device using microwaves such as a microwave oven employs a magnetron driven at a high voltage of 4 kV as an ultra high frequency oscillation device. This magnetron is a kind of two-pole vacuum tube that generates microwaves, and as shown in FIG. 1, when electric power is applied to an input part composed of a capacitor 11, a coil 12, and the like, hot electrons emitted from the filament of the cathode 1 Is discharged into the working space 4 between the plurality of vanes 3 terminals and the filaments arranged radially on the inner wall of the cylindrical anode 2, which has a cathode 1 and an anode 2 in the working space 4. A high voltage of 4 kV is applied between the vanes 3 constituting the s) to form an electric field difference in the working space 4. 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 the hot electrons undergo a cycloid motion, and the energy of the motion is taken into the vane 3 and the strap ( 8), it was radiated to the cooking chamber through an output unit composed of an antenna 7 connected to the vane 3, an antenna ceramic 9, an antenna cap 10, and the like, thereby generating microwave energy.

As shown in FIG. 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. And a high frequency current is formed on the surface of the c), and the resonance frequency is determined by the "L" and "C" values acting between the vanes 3 to generate microwaves when a predetermined resonance condition is satisfied.

As the conventional magnetron is driven at a high voltage of about 4 kV, it requires expensive devices such as a high voltage transformer and a high voltage diode, and is driven at a high voltage, thereby causing a safety problem, and also caused by the movement of electrons in the electromagnetic field. Since the resonant method is adopted, a strong magnet is required, and thus, the weight is heavy and the manufacturing cost is high.

Meanwhile, US Pat. No. 5,541,391 discloses Klystron as an ultra-high frequency oscillating tube for a microwave oven. As shown, the klystron 40 includes an input terminal 42 for receiving power, a klystron body 41 for generating microwaves in response to the power supply of the input terminal 42, and the klystron body 41. And an antenna 32 for transmitting microwaves from the refrigerator, a cooling unit 43 for dissipating heat generated in the Klystron body 41 to the outside, and an electron beam concentrator 49 installed to receive electrons. 43 supports cooling fins 44 arranged to dissipate heat generated by the reception of electrons, to support cooling fins 44 and to transfer heat from the electron beam concentrator 49 to the cooling fins 44. It consists of an arrangement of cooling rods 46 and a closure surrounding the cooling fins 44.

The klystron 40 also includes an electron gun 50 that receives power through the input terminal 42 and generates electrons by the received power source, and a pair of magnets installed around the electron gun 50 and the electron beam concentrator 49. And a yoke 54 serving as a guide constituting the closed loop by the magnet 52, and a tube 56 sandwiched between the magnets 52 having a plurality of cavities.

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

However, since the Klystron as described above is still driven by high voltage, the input terminal must be insulated with a separate insulating member, a high voltage transformer is needed to boost the commercial voltage to high voltage, and a magnet is required for the concentration of the electron beam. There is a problem that this is expensive and the product becomes heavy. In addition, since the former motion is also complicated, excessive noise is generated, the cooling structure is complicated, and the cavity is formed to have a plurality of cavities.

The present invention has been made to solve the above problems, the technical problem of the present invention is to provide an ultra-high frequency oscillation device which is driven at low voltage and simple in structure and easy to manufacture.

Another technical problem of the present invention is to provide an ultra-high frequency oscillation apparatus having an improved performance of more precisely adjusting the amount and phase of the feedback energy by feeding back a portion of the generated ultra-high frequency energy by an external feedback method.

In order to achieve the above technical problem, the present invention provides a driving power generating means for outputting the input voltage to a voltage of a predetermined level;

A power input unit for receiving an output power of low voltage provided from the driving power generating means;

Heat generating means for generating heat by receiving power supplied from the power input unit;

An input cavity of a space surrounded by a cathode sequentially installed on the heat generating means, a first grid provided at a predetermined interval on the cathode, and a choke structure for insulating the first grid and the cathode, wherein the cathode Heated to a predetermined operating temperature by the heat of the heat generating means to emit hot electrons, the first grid is applied a bias voltage to control and focus the electrons emitted from the cathode, the choke structure is inside the input cavity An input cavity for energizing a surface current forming a microwave and shielding a direct current between the cathode and the first grid;

An output cavity of a space surrounded by a second grid aligned with an upper portion of the first grid and an anode disposed on the second grid and formed corresponding to the cathode, wherein the anode includes a plurality of cooling fins to cool heat. The stacked array extinguishes the decelerated electron beam, and the second grid induces a surface current while electrons passing through the first grid of the input cavity pass, and densely modulates the electrons focused on the input cavity. An output cavity that is accelerated by the potential difference between the first grid and the second grid and forms a microwave by the surface current induced in the second grid;

Radiating means for radiating microwaves formed in the output cavity;

A feedback means for feeding back a part of the microwaves formed in the output cavity from the output cavity into the input cavity, wherein the feedback means comprises a directional coupler for separating a part of the output power generated from the output cavity and a separate output; An attenuator for accurately reducing a part of the power to a required amount of power, a phase adjuster for accurately adjusting the phase of the power attenuated by the attenuator, and a position corresponding to the output cavity in the input cavity; Such feedback means constituted by a feedback rod whose part of the output power radiated from the output cavity is adjusted in phase with the output power and fed back;

It provides an ultra-high frequency generator composed of.

1 is a schematic cross-sectional view showing the structure of a magnetron used as a conventional ultra-high frequency oscillation 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 ultra-high frequency oscillation tube,

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

5 is a schematic cross-sectional view showing the structure of the ultra-high frequency oscillation apparatus of the present invention,

FIG. 6 is a schematic diagram illustrating an operating principle of the ultra-high frequency oscillation apparatus of FIG. 5.

<Explanation of symbols for main parts of drawing>

120: heater 130: input cavity

132: cathode 134: first grid

140: output cavity 142: second grid

146: anode 148: cooling fin

152: coupling end 160: feedback rod

210: directional coupler 220: attenuator

230: phase adjuster 260: choke structure

Hereinafter, a preferred embodiment of the ultra-high frequency oscillator of the present invention will be described in detail with reference to the accompanying drawings.

5 to 6, the ultra-high frequency oscillation apparatus 100 of the present invention is the power input unit 110, the heater 120, the input cavity in the shield case 105, the cover 104 is covered with a lower portion And a feedback rod 160 at the center lower portion of the input cavity 130, an output cavity 140, an anode 146 at the top of the output cavity 140, and an upper portion at the center of the output cavity 140. The end 152 and the antenna 150 of the anode 146 connected to the coupling end 152 are provided in the bracket 102. The installation space of the inside of the shield case 105 and the antenna 150 of the anode 146 maintains a vacuum. Bracket 102 is preferably the same as that used for conventional magnetrons for microwave ovens.

The ultra-high frequency oscillation tube 100 emits hot electrons by the cathode 132, which is an electron radiator, by an indirect heating method by heating of the heater 120 composed of an annular filament. That is, as shown in FIG. 6, when the cathode 132 placed on the upper surface of the heater 120 is heated to about 600 to 1200 ° C. by the heat generated by the heater 120, hot electrons are emitted.

The input cavity 130 is a space surrounded by the cathode 132, the first grid 134 provided at a predetermined interval on the cathode 132, and the choke structure 136 to insulate the cathode 132. 5 and 6, the cathode 132 is a ring-shaped disk or disc-shaped disk having a hole formed at the center thereof, and is heated to the operating temperature by the heating of the heater 120. Emits hot electrons. The first grid 134 provided at a predetermined interval on the cathode 132 has a bias voltage applied thereto to control and focus electrons emitted from the cathode 132 to the input cavity 130. At this time, in order to be electrically insulated between the first grid 134 and the cathode 132, more specifically, the direct current therebetween is shielded, and the surface current forming the microwaves in the input cavity 130 is energized. In order to achieve this, the choke structure 136 is installed between the cathode 132 and the first grid 134. The gap of the choke structure 260 is λ / 4.

The output cavity 140 arranged above the input cavity 130 includes a second grid 142 facing the first grid 134 of the input cavity 130 with a predetermined gap, and the cathode at the bottom surface thereof. A space surrounded by an anode 146 having protrusions projecting downward in a portion corresponding to 132, in which the electrons focused on the input cavity 130 are densely modulated with the first grid 134 and the second. Microwaves are formed by the surface current induced in the second grid 142, accelerated by the potential difference between the grids 142. The anode 146 which dissipates the decelerated electron beam is also stacked with a plurality of cooling fins 148 to radiate heat.

As shown in FIG. 6, the first and second grids 134 and 142 are metals, and have the same shape and material as the cathodes, and have a circumferential direction at a position corresponding to the cathode 132. Accordingly, slots or hole-shaped openings 170 and 180 are formed, and the electron beam emitted from the cathode 132 passes through the openings.

The electrons focused on the input cavity 130 are densely modulated by the shielding function of the bias power of the first grid 134 to pass through the first grid 134, and the input / output cavities 130 and 140 are insulated from each other. When a low operating voltage of approximately 500 to 700 VDC is applied therebetween, a potential difference therebetween is generated, and electrons passing through the first grid are accelerated to pass through the second grid 142, so that the output cavity 140 is in the output cavity 140. Surface currents are induced. As a result, microwaves are formed in the output cavity 140, and the formed microwaves penetrate through the center of the anode 146 and are radiated through the antenna 150 formed in the output cavity 140. To this end, the coupling end 152 of the antenna 150 is located in the output cavity 140. The antenna ceramic 154 and the antenna cap 156 connected to the center upper portion of the antenna 150 have the same structure as a conventional magnetron.

Meanwhile, a feedback means for feeding back a part of the microwaves formed in the output cavity 140 from the output cavity into the input cavity 130 is provided. The feedback means includes a directional coupler 210 for separating a part of the output power generated from the output cavity 140, and an attenuator 220 for accurately reducing the power to a part of the separated output power. And a phase adjuster 230 for accurately adjusting the phase of the power attenuated by the attenuator 220 and installed at a position corresponding to the output cavity 140 in the input cavity 130. A portion of the output power radiated from the) is adjusted to the same phase as the output power is composed of a feedback rod 160 to feed back into the input cavity (130).

In addition, since a high voltage of several hundreds to thousands of volts is applied to the cathode part including the heater 120 and the cathode 132, the choke structure 260 is installed on the input line to insulate it, thereby safely operating. The gap of the choke structure 260 is λ / 4.

As described above in detail, according to the ultra-high frequency oscillation apparatus of the present invention, not only the stability to high pressure is secured compared to the ultra-high frequency oscillation apparatus, but also the weight reduction is achieved because the high-voltage circuit portion is not required as compared to a conventional magnetron. The use of two grids to focus the electron beam eliminates the need for an external magnetic field magnet. This eliminates the need for a separate bias power supply from the outside, reducing the cost of the product.

When coupling part of the power in the space where the directional coupler is installed, the proper amount of power required for input is separated from the energy emitted through the antenna connected to the coupling end of the output cavity instead of feeding back to the center of the input cavity. The phase and energy amount of the feedback power can be further optimized by adjusting the phase accurately and feeding back to the feedback rod by accurately adjusting the phase compared to the output power in the output cavity through the phase adjuster.

Claims (4)

Drive power generation means for outputting an input voltage to a voltage having a predetermined level; A power input unit 110 for receiving an output power of low voltage provided from the driving power generating means; Heat generating means (120) for generating heat by receiving power supplied from the power input unit; A cathode 132 sequentially installed above the heat generating means to emit hot electrons, a first grid 134 installed at a predetermined interval on the cathode to control and focus electrons emitted from the cathode, and the first An input cavity 130 in a space surrounded by a choke structure 136 for insulating one grid and the cathode; The second grid 142 arranged at a predetermined interval on the upper portion of the first grid and a plurality of cooling fins arranged on the second grid in correspondence with the cathode and cooled in a plurality of layers to cool the heat. An output cavity 140 of a space surrounded by the anode 146 which extinguishes it; Radiating means (152) for radiating microwaves formed in the output cavity; A feedback means for feeding back a portion of the microwaves formed in the output cavity from the output cavity into the input cavity, wherein the feedback means comprises a directional coupler 210 for separating a part of the output power generated from the output cavity; An attenuator 220 for accurately reducing a portion of the separated output power to a required amount of power, a phase adjuster 230 for accurately adjusting the phase of the power attenuated by the attenuator, and the Such feedback means constituted by a feedback rod (160) installed at a position corresponding to the output cavity and configured to feed back a portion of the output power radiated from the output cavity in phase with the output power; Ultra-high frequency generator, characterized in that consisting of. The feedback input line of claim 1, wherein a portion formed of the heat generating means 120 and the cathode 132 of the input cavity 130 and the feedback means installed at the center lower portion of the input cavity are insulated from each other. The choke structure (260) is installed so that it is safely operated, and the gap of the choke structure (260) is characterized in that the λ / 4 so that the ultra-high frequency generator. The choke structure 136 for insulating the first grid 134 and the cathode 132 is formed such that the gap of the structure is λ / 4 so that the microwave inside the input cavity 130. Ultrasonic wave generator, characterized in that the conduction of the surface current to form a, direct current between the cathode (132) and the first grid (134) is shielded. The method of claim 1, wherein the first grid 134 and the second grid 142, slots or hole-shaped openings 170, 180 in the circumferential direction is formed at a position corresponding to the cathode 132, Ultra high frequency generator characterized in that the electron beam emitted from the cathode (132) through the opening (170, 180) is focused and passed through.