JP3036006B2 - Traveling wave tube - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a traveling wave tube, and more particularly, to a heat radiation structure of a high-frequency circuit section.

2. Description of the Related Art A traveling wave tube includes an electron gun for emitting an electron beam, a high frequency circuit for amplifying a high frequency by an interaction between the electron beam and a high frequency, a collector for capturing the electron beam after the interaction, and an electron. It comprises a periodic magnetic field focusing device for focusing the beam.

The high-frequency circuit is heated by the heat due to the collision of the electron beam, which is out of the ordinary orbit, and the heat due to the high-frequency loss accompanying the propagation of the high-frequency.

This will be described with reference to the cross-sectional view of the conventional high-frequency circuit shown in FIG. The figure is a cross-sectional view of the high-frequency circuit of the helical traveling wave tube. In this case, the heat dissipation path includes a helix 1 and a plurality of dielectric supports 2 and a helix shell. (Not shown in the drawing), the pole piece 3, the toroidal magnet 4, the support 5 closely contacting the lower half of the periodic magnetic field concentrator, and the case substrate 6. The shape of the support 5 may be a block shape as shown in FIG. 3 (b) or a plate-like shape as shown in FIG. 3 (c).

In the case where the heat generated in the high-frequency circuit is large, the heat dissipation efficiency is improved by fixing the heat dissipation cover 11 to the support 5 with screws 12 or the like as shown in FIG.

[Problems to be solved by the invention]

However, the conventional structure has a drawback that heat generated in the high-frequency seaway flows to the lower part where the pole piece and the annular magnet are in close contact with the support, the heat flux becomes large, and the heat radiation efficiency is poor.

Further, since the magnet has a temperature coefficient of about -0.04% / ° C., if heat escapes to only one side, a polarized magnetic field is generated, which deteriorates the temperature characteristics of the traveling wave tube. Due to this magnetization, the trajectory of the electron beam passing through the high-frequency circuit is disturbed, so that the amount of electrons colliding with the high-frequency circuit increases, and the amount of heat generated in the high-frequency circuit increases. Further, since the high-frequency loss due to the propagation of the high-frequency wave is equivalent to about 20% of the output power and is proportional to the output power, improvement measures such as mounting a heat dissipation cover have been implemented with the increase in the power of the traveling-wave tube. However, the effect is small. Another problem is that fine adjustment of the magnetic field of the periodic magnetic field focusing device is usually performed by attaching an iron piece to a pole piece or an annular magnet. There were drawbacks of not sticking and little effect.

[Means for solving the problem]

The traveling wave tube of the present invention is a pair of a metal made of a metal having a high thermal conductivity such as copper or aluminum so as to be sandwiched from both sides around the outer periphery that is not in close contact with the support of the periodic magnetic field focusing device including the pole piece and the annular magnet. A heat radiating component is attached to radiate heat to a relatively low temperature portion where the support of the case substrate is not fixed, and further to a case cover.
A plurality of pairs of the heat dissipating parts are attached at intervals.
As a result, the heat dissipation efficiency is improved, and a polarized magnetic field generated in the annular magnet can be prevented.

〔Example〕

Hereinafter, the present invention will be described with reference to the drawings. FIG. 1 (a) is a cross-sectional view of a high-frequency circuit portion of a helical traveling-wave tube according to a first embodiment of the present invention, FIG. 1 (b) is a perspective view showing a heat dissipating component, and FIG. ) Is A- in FIG. 1 (a).
The view from the arrow A 'is shown. The heat generated in the helix 1 is radiated to the pole pieces 3 and the annular magnets 4 arranged alternately in the axial direction through a plurality of dielectric columns due to the high frequency loss caused by the collision of the electron beam and the propagation of the high frequency. The heat is radiated from the pole piece 3 and the toroidal magnet 4 to the case substrate 6 through the support member 5 which is in close contact with the lower portion, and to the case substrate 6 through the heat dissipating component 10 which is in close contact with the side surface and the upper portion.

FIG. 2A is a cross-sectional view of a second embodiment of the present invention, and FIG. 2B is a perspective view of a heat dissipation component. In this embodiment, the heat dissipation component 10 is connected to the case cover 7 to further improve the heat dissipation efficiency.

〔The invention's effect〕

As described above, according to the present invention, a pair of heat radiating components made of metal having high thermal conductivity such as copper and aluminum are sandwiched between portions of the pole piece and the support of the toroidal magnet that are not closely contacted so as to be sandwiched from both sides. It is possible to improve the heat radiation efficiency of the high frequency circuit because it is possible to dissipate heat over a wide area to the part where the support of the case board is not connected. it can.

Further, even when the ring-shaped magnet is viewed alone, heat is radiated from the entire outer periphery, so that a temperature difference is unlikely to occur. In other words, there is an effect that a magnetic field is hardly generated.

Furthermore, the heat dissipating parts can be attached after fixing the support and the high frequency circuit to the case substrate, and the number and location of the heat dissipating parts can be adjusted according to the heat generation amount and the heat distribution for each tube. The increase in weight due to the mounting of parts can be minimized as necessary.

Also, fine adjustment of the magnetic field, which is performed by attaching iron pieces, can be easily adjusted because the surface is sufficiently exposed.

[Brief description of the drawings]

FIG. 1A is a cross-sectional view of a first embodiment of the present invention.
FIG. 1 (b) is a perspective view of the heat dissipating component, FIG. 1 (c) is a view taken along the line AA 'of FIG. 1 (a), and FIG.
2 (b) is a perspective view of a heat radiating component, FIG. 3 (a) is a cross-sectional view of a conventional high-frequency circuit, and FIG.
(B) and (c) are perspective views showing an example of a support, and FIG. 4 is a cross-sectional view of another example of a conventional high-frequency circuit. DESCRIPTION OF SYMBOLS 1 ... Helix, 2 ... Dielectric support, 3 ... Pole piece, 4 ... Annular magnet, 5 ... Support, 6 ... Case board, 7 ... Case cover, 10 ... Heat dissipating component, 11 … Heat dissipation cover, 12 screws, 13 iron pieces.

Claims (1)

(57) [Claims] 1. A periodic magnetic field concentrator having a plurality of annular permanent magnets and pole pieces alternately and coaxially arranged on the outer periphery of a high frequency circuit, and closely contacted with and supported by a lower half outer periphery of the periodic magnetic field concentrator. In a traveling wave tube having a support to be fixed and a case substrate to which the support is fixed, the traveling substrate is closely contacted with the outer periphery of the periodic magnetic field focusing device that does not contact the support so as to be sandwiched from both sides, and the case substrate A traveling wave tube comprising a plurality of sets of a pair of heat dissipating parts joined to each other at intervals.