JPH0711938B2 - Microwave tube - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a collector of a microwave tube such as a klystron or a traveling wave tube, and more particularly to a microwave whose efficiency is improved by lowering the collector voltage below the potential of a high frequency circuit. Regarding the collector structure of the tube.

[Conventional technology]

In the microwave tube generally used for the transmitter of the microwave radio communication line relay station, satellite communication ground station, etc.,
Low power consumption, that is, high efficiency is required in terms of device design and economy. As a means for improving efficiency, a potential-decreased collector in which collector power is reduced by lowering the collector potential below the high-frequency circuit potential is widely used.

When the electron beam interacts with the high-frequency circuit, the coupling states thereof are different from each other and the velocity is modulated, so that the kinetic energy of the electron beam after the interaction causes velocity dispersion.
Therefore, the potential can be lowered to a potential at which the slowest electron beam group can be captured. However, if the potential is further reduced to further improve the efficiency, a part of the primary electron beam group that does not have a sufficient velocity to be trapped by the collector and the secondary electrons generated from the inner surface of the collector are more likely to be emitted. It goes back to the high-potential high-frequency circuit section and acts on the high-frequency circuit, adversely affecting the transmission characteristics such as amplitude distortion and phase distortion, and causing abnormal oscillation, unstable operation, etc. This hinders efficiency improvement. Therefore, in order to prevent retrograde electrons, a deflection magnet is attached to the outside of the collector to apply a magnetic field to the surface inside the collector perpendicular to the tube axis, and the Lorentzker that acts on the electrons bends the electron trajectory to prevent retrograde to the high frequency circuit. Measures are being taken to do so.

[Problems to be solved by the invention]

However, in the case of a forced air-cooled microwave tube, since the radiator blades made of copper with good thermal conductivity are brazed to the outer circumference of the collector core in a radial fashion, the deflection magnet is placed near the collector core. Cannot be installed on. Therefore, the deflection magnet is attached to the outside of the radiator blade, but since the deflection magnet is separated from the collector core, the magnetic field applied inside the collector core weakens in inverse proportion to the square of the distance and acts on electrons. The Lorentzka becomes extremely weak and the effect of preventing retrograde electrons becomes small. As a result, the conventional forced air cooling type microwave tube has a drawback that the collector potential cannot be sufficiently lowered with respect to the high frequency circuit potential, so that the efficiency improvement is limited.

[Differences from the Prior Art of the Invention]

In contrast to the conventional forced-air cooling type microwave tube collector structure described above, the present invention is arranged such that a ferromagnetic material such as iron is arranged point-symmetrically with respect to the tube axis at the collector inlet portion, and a strong material such as iron is arranged around the heat dissipation blade. Applying a sufficiently strong deflection magnetic field to the inside of the collector core without weakening the deflection magnetic field by arranging a magnetic material and constructing a magnetic feedback circuit in the collector core section with a deflection magnet attached to the outside of the radiator blade. It has the original content that you can do it.

[Means for solving problems]

The forced air-cooled microwave tube according to the present invention includes an electron gun portion that radiates and forms an electron beam, a high frequency circuit portion that performs high frequency amplification by interaction with the electron beam, and a focusing magnetic field device that focuses the electron beam in the high frequency circuit. Part and a collector part for trapping the electron beam that contributed to amplification by the interaction with the high-frequency circuit. The collector part is made of non-oxygen-free oxygen-free copper and has a ferromagnetic core such as iron at the inlet part of the collector core. The material is arranged point-symmetrically with respect to the tube axis, a deflection magnet is attached to the outside of the collector in the vicinity of the material, and a ferromagnetic material such as iron is arranged around the heat dissipation blade.

〔Example〕

 Next, the present invention will be described with reference to the drawings.

FIG. 1 is a vertical sectional view of an embodiment of the present invention, and FIG.
The sectional view on the AA of the collector part of a figure is shown.

The microwave tube is composed of an electron gun section 1, a high frequency circuit section 2, a focusing magnetic field device section 3 and a collector section 4, and the collector section 4 includes a collector core 5 and a radiating blade 6 and a collector fixed to the outer periphery thereof by brazing. It is composed of a deflection magnet 7 attached to the outside.

The collector core 5 is made of non-magnetic oxygen-free copper having a high thermal conductivity, and a ferromagnetic material 8 such as iron is brazed to a part of the material of the inlet portion at a position symmetrical with respect to the tube axis. Etc., and a ferromagnetic material 9 such as iron is fixed to the outer peripheral portion of the radiator blade 6.

The deflection magnet 7 is attached to the vicinity of the ferromagnetic material 8 outside the collector, and is attached so that the magnetic field is directed toward the center of the collector core 5, so that the deflection magnet 7 is arranged at the inlet of the collector core 5 as shown in FIG. By forming a magnetic feedback circuit in which magnetic lines of force pass through the ferromagnetic material 8 and return to the ferromagnetic material 9 outside the heat radiating blade 6, a sufficiently strong magnetic field is generated in a plane perpendicular to the tube axis at the inlet of the collector core 5. be able to.

〔The invention's effect〕

As described above, according to the present invention, a ferromagnetic material such as iron is placed in a part of the material of the inlet portion of the non-magnetic oxygen-free copper collector core in a point-symmetrical position with respect to the tube axis, and in the vicinity of this. By attaching a deflection magnet to the outside of the collector and arranging a ferromagnetic material such as iron so as to cover the outer circumference of the radiator blade, a magnetic feedback circuit was formed at the collector inlet, and a magnetic feedback circuit was formed perpendicular to the collector inlet tube axis. Since a sufficiently strong magnetic field can be generated on the surface, it acts on return electrons and secondary electrons to bend their orbits and effectively prevent backflow to the high frequency circuit.

Therefore, the collector potential can be drastically reduced, and the efficiency can be improved.

[Brief description of drawings]

FIG. 1 is a longitudinal sectional view of an embodiment of the present invention, and FIG. 2 is a sectional view taken along the line AA of the collector section in FIG. 1 ... Electron gun section, 2 ... High frequency circuit section, 3 ... For focusing Magnetic field device section, 4 ... Collector section, 5 ... Collector core, 6
...... Radiating blades, 7 ...... Deflection magnets, 8, 9 ...... Ferromagnetic materials, 10 ...... Insulating stones.

Claims (1)

[Claims] 1. An electron gun section for radiating and forming an electron beam, a high frequency circuit section for high frequency amplification by interaction with the electron beam, a focusing magnetic field device section for focusing the electron beam in the high frequency circuit, and a high frequency circuit. In a microwave tube composed of a collector section that captures an electron beam that has contributed to amplification by the interaction of, the collector section has a ferromagnetic material such as iron at its entrance and is arranged point-symmetrically with respect to the tube axis. A microwave tube characterized in that a deflection magnet is attached to the collector side in the vicinity of the ferromagnetic material, and further the ferromagnetic material is arranged so as to cover the outer peripheral portion of the collector at the inlet of the collector core.