JP2008091258A - Microwave generating device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a microwave generating device equipped with a phase variation means capable of continuously changing phases between a plurality of outputs of the device as a freely detachable structure. <P>SOLUTION: A phase variation means 21 connected to both end parts (point A and point B) of a microwave transmission path 14a connecting a distribution part 12 and an initial step amplification part 13a of the microwave generating device 10 is provided with a zigzag-shaped microwave transmission path 24 connecting an input part 22 and an output part 23, and a semi-circle dielectric plate 28 covering a given area of the microwave transmission path 24, and the dielectric plate 28 is made to slide and rotate along the microwave transmission path 24 and delays phases of microwaves transmitted along the microwave transmission path 24. Then, a continuous change of phase delay volumes at the phase variation means 21 is reflected on a phase difference of two outputs of the microwave generating device 10, and, by applying two microwave signals with changing phase differences like this, uniformalizing of heating of various heated objects can be promoted. <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 type of microwave generator includes a semiconductor oscillation unit, a distribution unit that divides the output of the oscillation unit into a plurality of components, a plurality of amplification units that amplify the distributed outputs, and a synthesis that combines the outputs of the amplification units. And a phase shifter is provided between the distribution unit and the amplification unit (for example, Patent Document 1).

The phase shifter is configured to switch the microwave pass line length according to the on / off characteristics of the diode. In addition, the synthesis unit can use two 90 ° and 180 ° hybrids, so that the output of the synthesis unit can be made two. By controlling the phase shifter, the power ratio of the two outputs can be changed, or the phase between the two outputs can be changed. Can be in phase or out of phase.
JP 56-132793 A

  However, in the conventional configuration, even if a synthesizing unit that generates two outputs is used, the phase difference between the two outputs takes only a discrete value. It has been difficult to promote uniform heating.

  The present invention solves the above-mentioned conventional problems, presents a phase variable means capable of continuously changing the phase between a plurality of outputs of a microwave generator as a detachable structure, and can be used in various applications. An object of the present invention is to provide a microwave generator that can be realized.

  In order to solve the above-described conventional problems, a microwave generator according to the present invention is a microwave generator having a plurality of outputs configured using semiconductor elements, and a phase variable means for changing a phase difference between the plurality of outputs. Can be detachably attached to the microwave generator, thereby making it possible to easily realize high functionality of the microwave generator, and therefore, it is possible to provide microwave generators according to various uses.

  The microwave generator according to the present invention can provide a microwave generator that can be easily developed by using a detachable structure of phase variable means for changing the phase difference between a plurality of outputs.

  According to a first aspect of the present invention, in the microwave generator having a plurality of outputs configured using a semiconductor element, phase variable means for changing the phase difference between the plurality of outputs is detachably disposed in the microwave generator. Therefore, the microwave generator can be easily enhanced in functionality, and therefore, a microwave generator suitable for various purposes can be provided.

In the second invention, in particular, the phase varying means of the first invention has dielectric means having a shape covering a predetermined region of the microwave transmission path in the microwave generator, and the dielectric means is the microwave. Consists of a structure that varies the area covering the transmission line, which can continuously change the phase between multiple outputs, and when applied to a dielectric heating device, the heating is uniform for various objects to be heated. Can be promoted.

  According to a third invention, in particular, the phase varying means of the first invention has an input section, an output section, and a phase varying section provided between the input section and the output section, and before the phase varying means is mounted. The input unit and the output unit are connected to both ends of the microwave transmission path of the microwave generation apparatus of the above-mentioned microwave in radio waves, and the center of the microwave transmission path is grounded so that the phase variable means generates the microwave. It is configured to be mounted on the apparatus, and by making the phase variable means incorporating the phase variable unit detachable, the phase variable unit can be uniquely configured and the size can be reduced.

  In the fourth aspect of the invention, in particular, the microwave transmission line of the third aspect of the invention is (1/2 + (n-1)) with respect to the effective transmission wavelength of microwaves in the median frequency band generated by the microwave generator. × Effective transmission wavelength; n is a natural number, and has an effective length, which suppresses microwave transmission to the target microwave transmission line in the microwave generator, reduces transmission loss, and matches. The phase variable means can be implemented while maintaining the conditions.

  According to a fifth aspect of the invention, in particular, the phase variable section of the third aspect of the invention has dielectric means having a shape that covers a predetermined region of a microwave transmission path that connects the input section and the output section of the phase variable section, Since the dielectric means is configured to vary the region covering the microwave transmission path, the phase variable unit acts on the microwave transmission path independent of the circuit configuration of the mounted microwave generator. This makes it easy to check and guarantee the characteristics and performance.

  According to a sixth aspect of the invention, the dielectric means of the second or fifth aspect of the invention is a disk-like shape, and is configured to continuously vary the phase by being driven to rotate. Variable means can be provided.

  According to a seventh aspect of the present invention, in the microwave generator according to any one of the first to third aspects, an oscillation unit configured using a semiconductor element, a distribution unit that divides the output of the oscillation unit into a plurality, An amplification unit configured by using a semiconductor element that amplifies the output of each of the distribution units, and a configuration in which phase variable means is applied to a microwave transmission path between the distribution unit and the amplification unit; Therefore, by acting on a transmission line with low transmission power, heat generation of the dielectric means can be suppressed and reliability can be ensured.

  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 configuration diagram of a source circuit before mounting the phase varying means of the microwave generator according to the first embodiment of the present invention, and FIG. 2 is a circuit after mounting the phase varying means of the microwave generating apparatus. It is a block diagram.

  In FIG. 1, a microwave generator 10 includes an oscillating unit 11 configured using semiconductor elements, a distributing unit 12 that distributes the output signal of the oscillating unit 11, and outputs from the distributing unit 12 using subsequent semiconductor elements. Main amplifiers 15a, 15b, main amplifier 15a configured using semiconductor elements that further amplify the outputs of the microwave transmission paths 14a, 14b and the first amplifiers 13a, 13b leading to the configured first amplifiers 13a, 13b. , 15b and microwave transmission paths 17a, 17b for guiding the outputs of the microwave generator 10 to the output units 16a, 16b of the microwave generator 10.

The first stage amplifying units 13a and 13b and the main amplifying units 15a and 15b constitute a circuit with a conductor pattern formed on one side of a dielectric substrate made of a low dielectric loss material, and are semiconductor elements that are amplifying elements of the amplifying units. Matching circuits are arranged on the input side and the output side of each semiconductor element in order to operate the semiconductor device satisfactorily.

  The microwave transmission paths 14 a, 14 b, 17 a, and 17 b form a transmission circuit having a characteristic impedance of 50Ω by a conductor pattern provided on one side of the dielectric substrate 18. The microwave transmission path 14a has a zigzag transmission path configuration as shown in the figure, and a plurality of discontinuous conductor patterns 19a and 19b are disposed in the vicinity of the points A and B. The length of the microwave transmission path 14a between the point A and the point B is (1/1 /) of the effective transmission wavelength with respect to the center frequency of the microwave frequency band generated by the oscillation unit 11 of the microwave generator 10. 2+ (n-1)) times, where n is a natural number. A conductor pattern 20 that forms a ground potential connected to the back surface of the dielectric substrate 18 through a through hole is disposed in the vicinity of the center (point C) of the microwave transmission path 14a.

  FIG. 2 shows a configuration in which the phase varying means 21 is attached to the source configuration of the microwave generator 10 having the above-described configuration.

  In FIG. 2, the phase varying means 21 includes an input unit 22, an output unit 23, and a zigzag microwave transmission path 24 that connects the input unit 22 and the output unit 23. The microwave transmission path 24 forms a transmission circuit having a characteristic impedance of 50Ω by a conductor pattern provided on one surface of the dielectric substrate 25. The input unit 22 and the output unit 23 are connected by soldering to points A and B of the microwave transmission path 14a in the source circuit configuration of the microwave generator 10, respectively. In this connection, the coaxial lines 26 and 27 having a characteristic impedance of 50Ω and the discontinuous conductor patterns 19a and 19b are continuously connected by radio waves. The center (point C) of the microwave transmission path 14 a is electrically connected to the conductor pattern 20. The coaxial lines 26 and 27 are mounted and connected to the source circuit through a through hole provided in the outer case of the microwave generator.

  Further, a semicircular dielectric plate 28 is provided which is a dielectric means that covers a predetermined region of the microwave transmission path 24 of the phase varying means 21. The dielectric plate 28 is driven to rotate around the point D while sliding on the microwave transmission path 24. A rotating shaft 29 of the dielectric plate 28 is rotatably supported by an outer case of the phase varying means 21. The rotating shaft 29 is connected to an output shaft 31 of a drive motor 30 provided outside the phase varying means 21 by a belt 32. By operating the drive motor 30, the dielectric plate 28 rotates, and the area of the meat portion of the dielectric plate 28 that covers a predetermined region of the microwave transmission path 24 changes.

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

  By attaching the phase varying means 21 to the source circuit configuration of the microwave generator 10, the microwave transmission path 14a of the source circuit configuration has a transmission path length from point A to point C and a transmission path from point B to point C. Both lengths are (1/4 + (n-1) / 2) times the effective transmission wavelength, and n is a natural number. By connecting the point C to the conductor pattern 20 having the ground potential, the impedance viewed from the point A to the point C side and from the point B to the point C side becomes infinite, and the microwave flowing through the microwave transmission path 14a is Suppressed and transmitted microwaves are transmitted from the point A to the input unit 22 of the phase varying means 21. Further, the microwave transmitted from the output section 23 of the phase varying means 21 to the point B is efficiently transmitted to the first stage amplifying section 13a ignoring the presence of the microwave transmission path 14a.

Therefore, it is possible to suppress the microwave transmission to the target microwave transmission path 14a in the microwave generator 10, reduce the transmission loss, and maintain the matching condition and implement the phase variable means.

  Next, the operation of the dielectric plate 28 will be described. Microwaves that are input into the phase varying means 21 and transmitted through the microwave transmission path 24 are subjected to wavelength compression due to the presence of the dielectric plate 28. For this reason, the radio wave effective length of the microwave transmission path 24 is increased, and the phase until reaching the output unit 23 is delayed.

  Here, the phase delay amount will be described below. As an example of the effective relative permittivity of the dielectric plate 28 in the frequency band of microwaves to be transmitted, when PPS (polyphenylene sulfide) is used for the dielectric plate 28, the relative permittivity in the 2.45 GHz band is about 3.5. Yes, wavelength compression works with the reciprocal of the square root of the relative dielectric constant, so it simply undergoes about 45% wavelength compression. When the conductor treatment is not performed on the opposite surface of the dielectric plate 28 that slides on the microwave transmission path 24, an air layer is interposed between the outer case of the phase varying means 21 and the dielectric plate 28. When the air layer is connected in parallel to the body plate 28 and the thickness of the air layer increases, the effective relative dielectric constant decreases and the degree of wavelength compression also decreases. When the air layer is formed so that the wavelength compression is about 33%, the microwave transmission path 24 is not covered by the dielectric plate 28 as the electrical length of the microwave transmission path 24 that the dielectric plate 28 covers the maximum. In the case of 360 ° (one effective wavelength), covering the maximum region with the dielectric plate 28 results in an electrical length of about 540 ° and a phase delay of 180 ° at the maximum.

  Then, by making the dielectric plate 28 act on the microwave transmission path 24 independent of the source circuit configuration of the microwave generator, confirmation and guarantee of the microwave characteristics and performance can be facilitated.

  In addition, by making the phase variable means incorporating the phase variable unit detachable, the phase variable unit can be uniquely configured and the size can be reduced.

  In addition, the dielectric means has a disk shape and is configured to continuously change the phase by being rotationally driven, and a phase variable means having a compact structure can be provided.

  Then, the continuous change in the phase delay amount in the phase varying means 21 is reflected in the phase difference between the two outputs of the microwave generator 10, and two microwave signals with such a change in phase difference are applied to the dielectric heating device. By doing so, it is possible to promote uniform heating of various objects to be heated.

(Embodiment 2)
FIG. 3 is a circuit configuration diagram of the microwave generator according to the second embodiment of the present invention.

  The difference between the second embodiment and the first embodiment is that the dielectric plate 51, which is a component of the phase varying means 50, is directly applied to the source circuit configuration of the microwave generator 10. .

  That is, the dielectric plate 51 is mounted so as to cover a predetermined region of the zigzag microwave transmission path 52a that connects the output of the distribution unit 12 and the input unit of the first stage amplification unit 13a.

The dielectric plate 51 has a configuration in which the dielectric body 51a and the openings 51b are periodically arranged at a pitch of about 90 °. This is because the dielectric plate 51 is compared with the case where the dielectric plate 28 is made to act on the microwave transmission path 24 designed exclusively for the first embodiment, which is different from the source circuit configuration of the microwave generator. Therefore, it is made to correspond to using the drive motor 53 with a large output torque and a small number of rotations. Dielectric body 51a and opening 51b are
By arranging the periods at a pitch of 0 °, the phase variable period can be advanced even if the rotational speed is small.

  The outer case of the phase varying means is screw-assembled on the side wall surface, etc., which is the outer case of the microwave generator, so as to form an integral structure with the microwave generator. Also, unnecessary countermeasures against noise are avoided by electrically connecting the outer case of the microwave generator and the outer case of the phase varying means and assembling them at the same potential.

  According to the present invention described above, the microwave generators have the same configuration, and the phase variable function can be added based on the source circuit configuration, so that the microwave generators according to various applications can be easily provided. Can be configured and provided.

  In addition, since the dielectric plate, which is a dielectric means, is configured to vary the region covering one microwave transmission path separated from the distributor, the phase between a plurality of outputs can be continuously changed, When this microwave generator is applied to a dielectric heating device, uniform heating of various objects to be heated can be promoted.

  As described above, the microwave generator according to the present invention provides a microwave generator that can be easily developed by using a detachable structure as a phase variable unit that changes a phase difference between a plurality of outputs. Therefore, the present invention can be applied to uses such as a heating device using a dielectric heating as typified by a microwave oven, a garbage disposal machine, or a microwave power source of a plasma power source as a semiconductor manufacturing apparatus.

The circuit block diagram before the mounting of the phase variable means of the microwave generator in Embodiment 1 of this invention The circuit block diagram after mounting the phase variable means of the microwave generator in Embodiment 1 of this invention The circuit block diagram of the microwave generator in Embodiment 2 of this invention

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Microwave generator 11 Oscillator 12 Distribution part 13a, 13b, 15a, 15b Amplifier 14a, 52a Microwave transmission path 16a, 16b in microwave generator Multiple output part 21, 50 Phase variable means 22 Phase variable means Input part 23 Output part of phase variable means 24 Microwave transmission path 28, 51 in phase variable means Dielectric plate (dielectric means)
30, 53 Drive motor Point A, Point B Both ends of microwave transmission line Point C Center of microwave transmission line

Claims (7)

A microwave generator having a plurality of outputs constituted by using a semiconductor element, wherein a phase variable means for changing a phase difference between the plurality of outputs is detachably disposed on the microwave generator. The phase varying means includes dielectric means having a shape covering a predetermined area of the microwave transmission path in the microwave generator, and the dielectric means is configured to vary the area covering the microwave transmission path. Item 2. The microwave generator according to Item 1. The phase varying means includes an input section, an output section, and a phase varying section provided between the input section and the output section. 2. The structure according to claim 1, wherein the input unit and the output unit are connected to both ends by radio waves, and the phase variable means is attached to the microwave generator by grounding the center of the microwave transmission path. The microwave generator of description. The microwave transmission path is (1/2 + (n−1)) × effective transmission wavelength; n is an effective length of a natural number with respect to the effective transmission wavelength of the microwave of the median frequency band generated by the microwave generator. The microwave generator according to claim 3, wherein the microwave generator has a length. The phase variable section has dielectric means having a shape covering a predetermined area of the microwave transmission path connecting the input section and the output section of the phase variable means, and the dielectric means covers the microwave transmission path. The microwave generator according to claim 3, wherein the microwave generator is configured to be variable. The microwave generator according to claim 2 or 5, wherein the dielectric means has a disk shape and is configured to continuously change the phase by being rotationally driven. The microwave generator includes an oscillation unit configured using a semiconductor element, a distribution unit that divides the output of the oscillation unit into a plurality of units, and an amplification unit configured using a semiconductor element that amplifies the output of the distribution unit, respectively. The microwave generator according to any one of claims 1 to 3, wherein phase varying means is applied to a microwave transmission path between the distribution unit and the amplification unit.

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