JP2000306519A - Microwave/dc power converter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable an eletromagnetic wave in a microwave band including a millimeter wave band, in particular, an eletromagnetic wave having large electric power to be converted into DC power with high efficiency. SOLUTION: In a microwave/DC power converter 1, a magnetostatic field is applied to an interacting portion 14 of a waveguide by a magnetic field coil 30, and an electron beam 100 is accelerated by always subjecting the electron beam 100 generated by an electron gun 12 to electron cyclotron automatic resonance with a microwave 102 introduced form the outside. Consequently, electric power of the microwave is converted into electric power of the electron beam. Furthermore, the electron beam is electrostatically decelerated by a DC voltage generated by a load resistance 40, whereby the DC power is taken out to the outside.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a microwave / DC power converter for converting microwave power into DC power. By using this microwave / DC power converter as a DC power source, it can be used as a remote energy transmission system via microwaves, a power recovery system for unnecessary microwaves generated in high power microwave systems, and the like. .

[0002]

2. Description of the Related Art As a conventional power converter for directly converting microwaves to DC power, a converter using a semiconductor such as a diode called a rectenna has been put to practical use.

[0003]

However, this rectenna is unsuitable for application to a high power system because there is a problem in that the rectenna is damaged when used for microwaves with high power density. Further, application to a microwave having a short wavelength, such as a millimeter wave band, has not been realized from the viewpoint of power resistance characteristics and power conversion efficiency of an element such as a diode.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention has been made in view of the above circumstances, and in order to solve the conventional drawbacks, an electromagnetic wave of a microwave band including a millimeter wave band, in particular, a high-power electromagnetic wave is highly efficiently converted to a direct current. An object of the present invention is to provide a power converter suitable for converting power.

[0005]

An object of the present invention is to provide an electron gun having a cathode, a waveguide for guiding an electron beam generated by the electron gun, and a collector for collecting the electron beam guided by the waveguide. And an electron tube whose inside is substantially maintained in a vacuum, and wherein the microwave is introduced into the waveguide so that the electron beam in the waveguide is accelerated to an electron cyclotron automatic resonance state. Magnetic field applying means for applying a magnetic field in the waveguide, wherein the electron beam accelerated in the waveguide is decelerated by a DC voltage generated by a load connected between the collector and the waveguide or the cathode. The DC / DC power converter according to the present invention is characterized in that the DC / DC power is extracted.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a preferred embodiment of the present invention will be described in detail with reference to the drawings. FIG. 1 (A) schematically shows a preferred embodiment of a microwave / DC power converter of the present invention and a power supply configuration related thereto, and FIG. 1 (B) shows an operation corresponding to (A). Are schematically shown. As shown in FIG. 1A, the microwave / DC power converter 1 has an electron tube 10, which has an electron gun 12 for generating an electron beam 100,
It includes a cylindrical waveguide 14 for guiding the electron beam generated by the electron gun 12 and a collector 16 for collecting the electron beam guided by the waveguide 14 so that the inside is maintained at a high vacuum. It has an airtight structure. An electron gun power supply 22 of a DC power supply for generating an electron beam and guiding the electron beam to the waveguide 14 between the cathode 20 of the electron gun 12 and the waveguide 14.
Are connected with the polarities as shown. Microwave /
The DC power converter 1 also has a magnetic field coil 30 provided to surround the waveguide 14 along the longitudinal direction of the waveguide 14 for applying a magnetic field to the waveguide 14. FIG.
Numeral 40 indicates a load resistance R which is a load means of an external circuit connected between the collector 16 and the waveguide 14 of the microwave / DC power converter 1. The load means may include a reactance component instead of a pure resistance as long as it generates a DC voltage necessary for decelerating the electron beam as described later. The electron tube 10 is also provided with a ceramic vacuum window 34 for introducing a microwave (RF) 102 into the waveguide 14 at the center of the bowl-shaped cathode 20. Therefore, the cathode 20 has a ring shape with a bowl-shaped central portion missing. Incident mirror 42
Changes the direction of incidence of the microwaves and condenses them to form a vacuum window 3
4 to allow the light to enter the waveguide 14.
The incident mirror 42 may be any type as long as it can guide the microwave to the waveguide 14, and may not be used if it can directly guide the microwave.

Next, the operation of the microwave / DC power converter 1 shown in FIG. Inside the waveguide 14, the electron beam 100 and the incident microwave 102
Interact with each other as described later, so that the waveguide 14
Is hereinafter also referred to as an interaction unit as appropriate. Interaction part (waveguide)
A static magnetic field excited by an external magnetic field coil 30 is applied in the axial direction of 14. Specifically, by applying a static magnetic field having a strength corresponding to the frequency of the microwave from the external magnetic field coil 30 to satisfy the principle of the electron cyclotron automatic resonance, all the electrons always resonate with the microwave. Accelerated by microwave power. That is, the axial distribution of the static magnetic field strength is adjusted by the external magnetic field coil 30 so as to satisfy the electron cyclotron automatic resonance condition in which electrons resonate with the microwave and are accelerated by the power of the microwave. At this time, by optimizing the conditions, microwave power can be converted to electron beam power with an efficiency close to 100%. An electron beam is generated by the electron gun 12, accelerated, and driven into the interaction section 14 along the magnetic field. In the embodiment shown in FIG.
The microwave (RF) to be incident uses a short-wavelength microwave such as a millimeter wave. In order to introduce the short-wavelength microwave quasi-optically into the interaction unit 14,
As described above, the vacuum window 34 which is a microwave entrance is provided at the center of the cathode 20 of the electron gun 12, and as a result, a hollow electron beam is employed. That is, as shown, an electron beam having a hollow inside, that is, a cylindrical electron beam is used. In addition,
For example, a case of a microwave having a long wavelength such as 2 GHz will be described later. The microwave is focused on the waveguide 14 using the incident mirror 42 and propagates through the interaction unit 14.
The vacuum in the interaction section 14 is maintained by a vacuum window 34 made of ceramic. In the interaction section 14, the electron beam 100
Pass through a portion that is strongly coupled to the microwave 102.
That is, the power density of the microwave in the cross section perpendicular to the axial direction of the interaction unit 14 is variously distributed, for example, from the center of the cross section to the outer circumference by a microwave used such as a Gaussian distribution.
The electron beam 100 passes through the high density portion. Here, the applied magnetic field by the external magnetic field coil 30 is adjusted so that electrons are always accelerated by the microwave 102.
That is, by satisfying the electron cyclotron automatic resonance condition, the electron beam 100 continues to obtain energy from the microwave 102 while traveling in the axial direction of the waveguide 14, and the energy of the microwave 102 at the end of the interaction unit 14. Can be obtained in a state where the light beam has almost been transferred to the electron beam.

[0008] The principle of the electron cyclotron automatic resonance includes:
The energies of the individual electron beams to be accelerated have a property of being basically uniform with each other. Therefore, by applying a DC voltage corresponding to this energy to the electron beam, almost all of the electron beams are accelerated. The power can be electrostatically deprived, and can be taken out as DC power to an external circuit, that is, the load resistor 40. Specifically, as a feature of the electron cyclotron automatic resonance, the energies of the electrons in the electron beam have substantially the same value. That is, individual electron beams existing in a certain cross section perpendicular to the axial direction in the interaction section 14 have the same energy value. Here, the electron energy is Vo electron volts, and the current is Io
1 between the collector 16 and the interaction unit 14
The electric field of RIo is generated in the direction of arrow 44 shown in FIG. This becomes a deceleration electric field for the electron beam 100 and can take power from the electron beam 100. Where Io
Alternatively, the energy of the electron beam can be substantially recovered by adjusting Vo. Specifically, the magnitude of Io can be adjusted by changing the heating temperature of the cathode 20 and the power supply voltage of the electron gun power supply 22, and the magnitude of Vo can be adjusted by changing the power of the incident microwave. it can. The electron beam 100 is absorbed by the collector 16,
The energy consumption here is small because almost all energy is lost. The power of the lost electron beam 100 will be consumed by the external load 40. That is, the microwave / DC power converter 1 can be used as a DC power source for the current Io. FIG. 1B shows an electron beam 100.
7 shows how the power of the microwave and the power of the microwave 102 change with respect to the axial distance in the interaction section 14. FIG. 1B shows that as the microwave 102 travels in the axial direction, its power decreases, while the electron beam 100 increases with it. In this way, as the power of the microwave 102 travels in the axial direction, it is converted to the power of the electron beam 100.

FIG. 2 shows, for example, 2G as an incident microwave.
1 schematically shows a preferred embodiment of a microwave / DC power converter of the present invention when a microwave having a long wavelength such as Hz is used, and a power supply configuration related thereto. In FIG. 2, components indicated by the same or similar reference numerals as those shown in FIG. 1A indicate the same or similar components, and the different points will be described below without repeating the description. . The feature of the configuration shown in FIG. 2 lies in the waveguide type coupling system provided at the entrance of the interaction section 14a. Specifically, a microwave incident waveguide unit 50 is provided at the entrance of the waveguide 14a of the interaction unit, which is coupled at right angles to the waveguide 14a. A so-called waveguide E-bend is formed between the entrance of the waveguide 14a and the microwave incident waveguide portion 50, and a cut surface indicated by reference numeral 52 functions as a cut surface of the E-bend. Therefore, the microwave of, for example, 2 GHz incident from the microwave incident waveguide unit 50 is 9 GHz at the coupling portion between the microwave incident waveguide unit 50 and the waveguide 14a.
The collector 1 is bent at 0 degrees along the axial direction of the waveguide 14a.
Propagation in the direction of 6. A vacuum window 34a is provided at the entrance of the microwave incidence waveguide section 50 where the microwave enters to keep the inside of the waveguide 14a in a vacuum. Cathode 20
Since a does not need to pass microwaves, there is a central portion from which the electron beam 100 is emitted. Therefore, the emitted electron beam 100 has a solid shape without missing the center. The end of the waveguide 14a on the cathode 20a side is connected to the electron beam 10 emitted from the cathode 20a.
A hole 54 is provided to allow 0 to enter the waveguide 14a. The power conversion by the interaction between the electron beam 100 and the microwave 102 in the interaction section 14a is exactly the same as in the embodiment of FIG.

In the embodiment shown in FIGS. 1 and 2, one end of the load resistor 40 is connected to the waveguides 14 and 14a. However, the present invention is not limited to this, and may be connected to the cathodes 20 and 20a. Further, the shape of the waveguide is circular, but is not limited to this, and may be rectangular, elliptical, or the like.

[0011]

As described above, according to the present invention, input microwave power can be converted to DC power with an efficiency close to 100%, and this can be further functioned as a highly efficient DC power supply. be able to.

Further, since the present invention uses an electron tube without using a component such as a semiconductor, it can be used for high power microwaves. For example, a microwave generated by a high-power electron tube different from the electron tube used in the present invention is spatially transmitted as an electromagnetic beam, received and received as a DC power supply through the microwave / DC power converter of the present invention. A so-called high power energy space transmission system to be used can be realized. This can be applied to outer space using a satellite or a space station or between space and earth.

Further, it can be used as a high-efficiency recovery system for unnecessary microwaves generated in a high-power microwave system.

[Brief description of the drawings]

1 (A) schematically shows a preferred embodiment of the microwave / DC power converter of the present invention and a power supply configuration related thereto, and FIG. 1 (B) corresponds to FIG. Some are shown schematically.

FIG. 2 schematically shows a preferred embodiment of a microwave / DC power converter according to the present invention when a microwave having a long wavelength such as 2 GHz is used as an incident microwave, and a power supply configuration related thereto. .

[Explanation of symbols]

 1, 1a Microwave / DC power converter 10, 10a Electron tube 12, 12a Electron gun 14, 14a Waveguide (interaction part) 16 Collector 20 Cathode 22 Electron gun power supply 30 Magnetic field coil 34, 34a Vacuum window 40 Load resistance 42 Incident mirror 50 Microwave incident waveguide 100 Electron beam 102 Microwave

Claims (1)

[Claims] 1. An electron gun having a cathode, a waveguide for guiding an electron beam generated by the electron gun, and a collector for collecting the electron beam guided by the waveguide, and having a substantially internal structure. An electron tube held in a vacuum, and a magnetic field for applying a magnetic field in the waveguide to accelerate the electron beam in the waveguide in an electron cyclotron automatic resonance state by using a microwave introduced into the waveguide. Application means, and taking out DC power by decelerating the electron beam accelerated in the waveguide by a DC voltage generated by a load means connected between the collector and the waveguide or the cathode. Features microwave / DC power converter.