JP2008034166A - Microwave generation device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a microwave generating device in which a charging point of the microwave generating device is insulated against the ground potential and is constituted to supply electric power for which commercial power supply is rectified or rectified and smoothed. <P>SOLUTION: In an outer conductor 19b of a coaxial line 19, in the case an inner face part which goes along the outer periphery of an insulating member 38 and the inner face part which is fitted to the outer peripheral face of a metal tube 36 are formed and the coaxial line 19 is connected to the input end of an amplification part 13, the outer conductor 19b formed on the tip of the coaxial line 19 goes along the outer periphery of the insulating member 38, the center conductor 19a is inserted in a state of fitting into the conductor 27, and furthermore, the outer conductor 19b is inserted in a fitting state with the metal tube 36 having the conductor part in which the outer conductor 19b is arranged with a slit, thereby coaxial line connection having a prescribed insulating performance is completed. By this, this is equipped with a simple and highly economical electric power supply system without necessity of a circuit for which complicated and advanced stabilization technology is required, and mounting characteristics and safety applied with electric shock preventing measures in use are provided in combination. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a microwave generator configured using a semiconductor element used in a heating device using dielectric heating.

  Conventionally, this microwave generator has an oscillator using a semiconductor and a plurality of stages of power amplifiers that amplify the output of the oscillator, and generally includes a stabilized power supply circuit that supplies power to the oscillator and the plurality of stages of power amplifiers.

Some supply a voltage obtained by rectifying and smoothing a commercial power supply voltage (Patent Document 1).
Japanese Patent Laid-Open No. 53-1343

  However, in the conventional configuration, when the microwave generator is mounted on the heating device, the heating chamber for storing the object to be heated and the microwave generator are electrically connected to each other. Insulation structure was required.

  The present invention solves the above-described conventional problems, and is practical in which a charging point of a microwave generator configured to supply electric power obtained by rectifying a commercial power source or rectifying and smoothing a commercial power source is insulated from a ground potential. An object of the present invention is to provide a microwave generator that presents a configuration and is economical and easy to mount.

  In order to solve the above-described conventional problems, a microwave generation device of the present invention includes a microwave generation unit having an amplification unit configured using a semiconductor element, and a voltage obtained by rectifying a commercial power supply as a voltage applied to the amplification unit. Or, the commercial power supply is configured to apply a rectified and smoothed voltage, and the charging unit of the amplifying unit is insulated from the ground potential, thereby having a simple power supply system and preventing electric shock in use. It is possible to provide a microwave generator having both mountability and safety with countermeasures taken.

  The microwave generator of the present invention has a configuration in which a commercial power supply is rectified or rectified and smoothed, and a charging unit to which the voltage is applied is insulated from a ground potential, so that the complex and advanced stabilization is achieved. It is possible to provide a microwave generator that is economical and easy to mount without requiring power supply technology.

  According to a first aspect of the present invention, there is provided a configuration in which a microwave generating means having an amplifying unit configured using a semiconductor element and a voltage obtained by rectifying and smoothing a commercial power source are applied as a voltage applied to the amplifying unit. The charging unit of the amplifying unit is configured to be insulated from the ground potential, thereby having a simple and economical power supply system that does not require a complicated circuit requiring a high level of stabilization technology. It is possible to provide a microwave generator that has both mountability and safety that are provided with electric shock prevention measures in use.

The second invention has an oscillating unit for generating a microwave input to the amplifying unit of the first invention in particular, and the oscillating unit and the amplifying unit are insulated from each other. A stabilized power source can be used as the power source applied for driving, and the oscillation frequency can be stabilized or the frequency can be easily controlled.

  The third invention has an antenna part that radiates the microwave generated by the microwave generating means of the first invention in particular, and the antenna part and the amplifying part are insulated from each other. Since the ground part is insulated from the charging part, the antenna part can be mounted at an arbitrary place.

  According to a fourth aspect of the invention, in particular, the insulation configuration of any one of the first to third aspects of the invention is configured to be arranged on a coaxial line that transmits microwaves, and the oscillation unit, the amplification unit, and the antenna unit are coaxial lines. Each can be mounted and arranged freely.

  In the fifth aspect of the invention, in particular, the insulation configuration disposed on the coaxial line of the fourth aspect of the invention is a detachable configuration, and at least the outer conductors of both coaxial lines are fitted and assembled, thereby oscillating. Assembling of the unit, the amplifying unit, and the antenna unit is facilitated.

  According to the sixth aspect of the invention, in particular, the means for suppressing microwave leakage is arranged on the outer conductor to be fitted and assembled according to the fifth aspect of the invention, and microwave leakage from the insulating portion can be reliably suppressed.

  In the seventh aspect of the invention, in particular, the structure for suppressing the microwave leakage of the sixth aspect is a choke structure, and the conductor portion is provided with a slit periodically. Microwave leakage prevention performance can be maintained over a wide band, and microwave leakage prevention performance corresponding to variable frequency control of the oscillation unit can be achieved.

  The eighth invention has a structure in which the width of the conductor portion of the seventh invention is changed in at least two stages, thereby forming transmission lines with different characteristic impedances and compacting the microwave leakage prevention structure. Can be realized.

  In the ninth aspect of the invention, the central conductors of both the coaxial lines in the insulating configuration particularly arranged in the coaxial line of the fourth aspect of the invention are configured to be fitted and joined together with the external conductor of the fitting configuration. It is possible to steadily configure the insulation configuration, assuring insulation performance and suppressing microwave transmission loss.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the present invention is not limited to the embodiments.

(Embodiment 1)
FIG. 1 is a circuit diagram of a microwave generator according to a first embodiment of the present invention, FIG. 2 is a configuration diagram of an amplification unit of the microwave generator of FIG. 1, and FIG. 3 is an insulation in the coaxial line of FIG. FIG. 4 is an enlarged configuration diagram of the structure, and FIG. 4 is a configuration diagram of a metal tube provided with the slits of FIG.

  1-4, the microwave generator 10 includes an oscillating unit 11 configured using semiconductor elements, a first stage amplifier 12 that amplifies the output signal of the oscillating unit 11 by one stage, and a plurality of stages that further amplifies the output signal of the first stage amplifier 12. And an antenna unit 14 that radiates microwaves connected to the output of the amplifier unit 13. In this embodiment, the amplifying unit 13 includes amplifiers 13a and 13b having a two-stage amplification configuration.

Further, as a power supply system of the microwave generator 10, a voltage obtained by full-wave rectifying the commercial power supply 15 with the full-wave rectifier 16 is supplied to each amplifier of the amplifying unit 13. The commercial power supply 15 outputs a plurality of DC voltages via the stabilizing power supply 17 and outputs the output voltages to the oscillation unit 11 and the first stage amplifier 12.
To supply.

  The voltages supplied to the amplifiers 13a and 13b of the amplifying unit 13 are individually controlled in supply timing by interposing a switch 18.

  The output of the first stage amplifier 12 and the input of the amplification unit 13 are connected by a coaxial line 19, and the output of the amplification unit 13 and the antenna unit 14 are connected by a coaxial line 20.

  And the insulation parts 21 and 22 of a coaxial line structure are provided in the input end and output end of the amplification part 13, respectively.

  The amplifying unit 13 includes a planar circuit 24 formed on one side of a printed circuit board 23 made of a low dielectric loss material, and each semiconductor device 131a, 131b, which is an amplifying element of each amplifier 13a, 13b, operates properly. An input matching circuit and an output matching circuit composed of planar circuits are arranged for the elements. The printed circuit board 23 and the semiconductor elements 131a and 131b are joined and attached to the heat radiation means 26 via a copper plate 25 having high thermal conductivity.

  Next, a configuration related to the insulation connection between the coaxial line formed at the input end and the output end of the amplifying unit 13 will be described below.

  First, the configuration of the coaxial line arranged at the input end and the output end of the amplifying unit 13 will be described.

  The conductors 27 and 28 respectively connected to the input end and the output end of the planar circuit forming the amplifying unit 13 are substantially central portions of the cylindrical metal tubes 31 and 32 through spacers 29 and 30 made of a low dielectric loss material. It is supported by. Coaxial lines are formed using the conductors 27 and 28 as the central conductors and the cylindrical metal tubes 31 and 32 as the outer conductors, respectively.

  Insulating members 33 and 34 having a low dielectric loss and a predetermined dielectric constant are disposed on the outer circumferences of the cylindrical metal tubes 31 and 32, and these insulating members 33 and 34 are brazed to the metal tubes 31 and 32. . Further, metal pipes 36 and 37 having conductor portions with periodic slits (35 in FIGS. 3 and 4) are arranged on the outer periphery of the insulating members 33 and 34, and the metal pipes 36 and 37 and the insulating member are arranged. 33 and 34 are soldered to each other. Furthermore, insulating members 38 and 39 having a low dielectric loss and a predetermined relative dielectric constant are arranged on the outer circumferences of the metal tubes 36 and 37 having the conductor portions provided with slits, and these insulating members 38 and 39 are the metal tubes 36 and 37. Is joined to the solder.

  Next, configurations and connection forms of the coaxial lines 19 and 20 connected to the coaxial lines arranged at the input end and the output end of the amplifying unit 13 will be described. Since the coaxial lines 19 and 20 have the same configuration, in the following description, the coaxial line 19 extending from the output of the first stage amplifier 12 connected to the coaxial line at the input end of the amplifying unit 13 will be described as a representative.

  The coaxial line 19 extending from the output of the first stage amplifier 12 is constituted by a central conductor 19a, an outer conductor 19b, and a spacer 19c made of a low dielectric loss material that supports the central conductor 19a. The outer conductor 19b of the coaxial line 19 has a configuration in which an inner surface portion along the outer periphery of the insulating member 38 and an inner surface portion fitted to the outer peripheral surface of the metal tube 36 are formed at one end of the coaxial line. Thereby, when connecting the coaxial line 19 to the input end of the amplifying unit 13, the outer conductor 19 b formed at the tip of the coaxial line 19 is along the outer periphery of the insulating member 38 and the center conductor 19 a is fitted to the conductor 27. The coaxial line connection having a predetermined insulation performance is completed by inserting the outer conductor 19b in a fitted state with the metal pipe 36 having a conductor portion with slits.

  In FIG. 2, the charging points of the rectified voltage or rectified smoothing voltage of the commercial power supply are P1 and P3 for the semiconductor element 131a and P2 and P3 for the semiconductor element 131b.

  The outer periphery of the amplifying unit 13 is covered with an insulating case 39 made of an insulating member. The insulating case 39 is provided with holes for distributing cooling air to the heat radiating means 26.

  About the microwave generator comprised as mentioned above, the operation | movement and an effect | action are demonstrated below.

  Here, the insulating portion 21 of the insulating portions 21 and 22 will be described as a representative. In the insulating part 21, a metal tube 31 that is an outer conductor of a coaxial line provided at the input end of the amplifying part 13 is electrically connected to the outer case 40 of the amplifying part 13. A gap (indicated by G in FIG. 3) formed between the metal pipe 36 having the conductor portion provided with the slit is provided with an insulating member 33 having a predetermined length, for example, 2 mm. The insulation between the outer case 40 of the amplifying unit 13 which is one of the charging units and the metal tube 36 having the conductor portion provided with the slit is ensured. As a result, the outer conductor 19b of the coaxial line 19 joined to the metal pipe 36 having the conductor portion provided with the slit is insulated from the charging portion from the commercial power source and is electrically connected to the outer conductor 19b of the coaxial line 19. All the members can secure insulation against the charging part of the commercial power source.

  Further, the outer conductors 19b and 29 of the coaxial line in the insulating portion 21 are not electrically connected by the interposition of the insulating member 33, but the metal pipe 36 having a conductor portion provided with the outer conductor 29, the insulating member 33, and the slit 35, By forming a structure that suppresses microwave leakage by the insulating member 38 and the external conductor 19b, microwave leakage due to the interposition of the insulating member 33 is suppressed. The function of the structure for suppressing the microwave leakage is as follows.

  That is, a metal short-circuit surface (impedance is zero) formed at a junction point (indicated by C1 in FIG. 3) between the outer conductor 19b and the metal tube 36 having a conductor portion provided with a slit is used, and the insulating member 33 is a coaxial line. The impedance at the point facing the central conductor (C3 in FIG. 3) is substantially zero. In order to achieve this, the electrical length of the conductor portion provided with the slit of the metal tube 36 is substantially 90 ° with respect to the frequency band generated by the microwave generator 10.

  Further, the substantial length of the conductor portion is made compact by utilizing the wavelength compression action by the relative dielectric constant of the insulating members 33 and 38. As a result, the metal tube 36 and the outer conductor 19b form a choke structure, and the zero impedance at the point C1 in FIG. 3 becomes infinite at the point C2. Further, the metal tube 36 and the outer conductor 31 form a choke structure, and the infinite impedance at the point C2 is set to an extremely small value at the point C3. Thereby, microwave leakage through the insulating member 33 is suppressed.

  In addition, since the choke structure has a structure in which slits are periodically provided, the microwave leakage prevention performance can be maintained over a wide frequency band, and the variable frequency control of the oscillation unit is supported. Microwave leakage prevention performance can be achieved.

  In addition, the central conductor of both coaxial lines in the insulation configuration arranged on the coaxial line is configured to be mated and joined, so that the insulation configuration can be steadily configured integrally with the external conductor of the fitting configuration, and the insulation performance is guaranteed. At the same time, transmission loss of microwaves can be suppressed.

  With such a configuration and operation, it is easy to mount and secure with a simple and economical power supply system that does not require complicated and high-level stabilization technology circuits, and with measures to prevent electric shock during use. Can be provided.

  Further, since the oscillation unit is insulated from the amplification unit 13, a stabilized power source can be used as a power source applied to drive the oscillation unit, and the oscillation frequency can be stabilized or the frequency can be easily controlled. can do.

  Since the antenna unit is also insulated from the amplifier unit 13, the ground part of the antenna unit is insulated from the charging unit, so that the antenna unit can be mounted at an arbitrary place.

  In addition, since the insulating configuration is a configuration in which it is arranged on a coaxial line that transmits microwaves, the oscillating unit, the amplifying unit 13 and the antenna unit can be freely mounted and arranged via the coaxial line.

  In addition, the insulation configuration arranged on the coaxial line is a detachable configuration, and at least the outer conductors of both coaxial lines are fitted and assembled, so that the oscillation unit and the antenna unit can be assembled to the amplification unit 13. It becomes easy.

  Note that the drive power of the first-stage amplifier arranged in the first embodiment is supplied from a stabilized power supply. This is an amplifier that applies a voltage obtained by rectifying and smoothing a commercial power supply or a voltage obtained by rectifying and smoothing the commercial power supply. The amplifier unit 13 is configured to be different from the driving power source system, and the first stage amplifier may not be provided, or may be configured by a plurality of stages of amplifiers that receive power supply from the stabilized power source. Absent. Furthermore, the amplifying unit 13 may have a configuration in which an amplifier operating in parallel is arranged. In short, any amplifier that applies a voltage obtained by rectifying a commercial power supply or a voltage obtained by rectifying and smoothing a commercial power supply is mounted in the amplifying unit 13. Is.

(Embodiment 2)
FIG. 5 is an enlarged configuration diagram of an insulating structure in a coaxial line to be insulated and connected in the microwave generator according to the second embodiment of the present invention, and FIG. 6 is a configuration diagram of a metal tube provided with a slit of the coaxial line in FIG. Is shown.

  In the metal tube 50 with the slit according to the second embodiment, compared with the metal tube 36 with the slit according to the first embodiment, the width dimension of the conductor portions 51 arranged periodically by providing the slit is set. The configuration is changed to two stages. In the conductor portion 51, the width dimension on the front end side is increased. As a result, the characteristic impedance on the base side of the conductor part 51 in the choke structure is increased and the characteristic impedance on the tip side of the conductor part 51 is reduced, and the total length of the choke structure from C11 to C22 is reduced to the first embodiment. Compared to the same width dimension as shown in the form, it can be made more compact.

  On the other hand, the metal tube 50 provided with slits also for the choke structure extending from C22 to C33 acts as a transmission line, so the overall length of the choke structure is longer than that of the structure in the first embodiment. Thus, the impedance in the insulating portion G1 is formed to an extremely small value.

  As a result, the outer conductor 191b of the coaxial line has a portion with a different inner diameter compared to the first embodiment, and is inserted and assembled with two different cylindrical diameters on the outer surface of the metal pipe 50 provided with the slit. It is possible to form a coaxial connection more reliably. By forming transmission lines with different characteristic impedances in the choke structure, it is possible to realize a coaxial line structure having a myo-wave leakage prevention structure with a wide transmission suppression frequency and having an insulation performance.

As described above, the microwave generator according to the present invention is practical in which the charging point of the microwave generator configured to supply the electric power obtained by rectifying or smoothing the commercial power supply is insulated from the ground potential. Since it is possible to provide a microwave generator that is economical and easy to mount by presenting the configuration, it is possible to provide a heating device, a garbage disposal machine, or a semiconductor manufacturing device that uses dielectric heating as represented by a microwave oven. It can also be applied to applications such as a microwave power source for a plasma power source.

Circuit diagram of microwave generator according to Embodiment 1 of the present invention Configuration diagram of the amplifying unit of the microwave generator of FIG. 1 is an enlarged configuration diagram of an insulating structure in the coaxial line of FIG. Configuration diagram of a metal tube provided with slits of the coaxial line in FIG. The expanded block diagram of the insulation structure in the coaxial line of the microwave generator in Embodiment 2 of this invention Configuration diagram of metal pipe with slits of coaxial line in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Microwave generator 11 Oscillating part 13 Amplifying part 14 Antenna part 15 Commercial power supply 16 Full wave rectifier 19, 20 Coaxial line 19a Center conductor 19b, 191b Outer conductor 21, 22 Insulating part 131a, 131b of coaxial line structure Semiconductor element 27, 28 Center conductor 31, 32 Metal tube (outer conductor)
33, 34, 38, 39, 331, 381 Insulating member 35 Slit 36, 50 Metal pipe with slit 51 Conductor part (change in width dimension in two steps)

Claims (9)

A microwave generation unit having an amplification unit configured using a semiconductor element, and a configuration in which a voltage obtained by rectifying a commercial power supply or a voltage obtained by rectifying and smoothing a commercial power supply is applied as a voltage to be applied to the amplification unit, and charging of the amplification unit A microwave generator having a configuration in which a part is insulated from a ground potential. The microwave generator according to claim 1, further comprising an oscillating unit that generates a microwave input to the amplifying unit, wherein the oscillating unit and the amplifying unit are insulated from each other. The microwave generator according to claim 1, further comprising an antenna unit that radiates microwaves generated by the microwave generation unit, wherein the antenna unit and the amplification unit are insulated. The microwave generator according to any one of claims 1 to 3, wherein the insulating configuration is a configuration in which the insulating configuration is arranged on a coaxial line that transmits microwaves. The microwave generator according to claim 4, wherein the insulating configuration disposed on the coaxial line is a detachable configuration, and at least an external conductor of both the coaxial lines is fitted and assembled. 6. The microwave generator according to claim 5, wherein means for suppressing microwave leakage is arranged on the external conductor to be fitted and assembled. The microwave generator according to claim 6, wherein the structure for suppressing the microwave leakage is a choke structure, and the conductor portion is provided with slits periodically. The microwave generator according to claim 7, wherein the width of the conductor portion is changed in at least two stages. The microwave generator according to claim 4, wherein the central conductors of both coaxial lines in the insulating configuration arranged on the coaxial line are configured to be fitted and joined.

Images