JPH0310241B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a non-reflection termination used for the purpose of absorbing the large power of microwaves of tens of watts or more propagating through a coaxial line.

[Conventional technology]

An example of a conventional device of this kind is one shown in the Shimada Rikasha Catalog 1982-1983 edition P85, and the outline drawing of this device is shown in FIG.

Its side cross-sectional shape is as shown in FIG. 5 or 6. In the figure, 1 is a coaxial plug, 2
is an outer wall, 3 is a heat dissipation fin provided on the outer wall 2,
4 is an inner conductor, 5 is a dielectric, and 6 and 7 are radio wave absorbers. 7 and 8 are external views of the radio wave absorbers 6 and 7.

Next, the operation will be explained. Radio waves incident from the input end of the coaxial plug 1 propagate in the direction of the arrow, but when they reach the area where the radio wave absorber (6 or 7) exists between the inner conductor 4 and the outer wall 5, part of the electromagnetic energy is lost. As it propagates, it is converted into thermal energy. That is, a radio wave attenuation phenomenon occurs. When the input radio waves have a large power level of several tens of watts or more, the amount of heat generated as the radio waves attenuate is also large, but by radiating this into the space via the heat dissipation fins 3 attached to the outer wall 2, the radio wave absorber 6.7 prevents heat rise. In addition, in order to suppress reflection when radio waves are incident on the radio wave absorbers 6 and 7, and to generate heat as evenly as possible, the shape of the radio wave absorbers is made into a conical taper shape as shown in Fig. 7 or 8. be.

[Problem that the invention seeks to solve]

Conventional non-reflective terminations are configured to dissipate heat by radiation from the heat dissipation fins as described above, so when used for high power applications, the heat dissipation fins become larger and the overall scale of the non-reflection termination increases. Furthermore, because of the coaxial shape, there were problems in the workability of forming the radio wave absorber into a conical taper shape, which led to problems such as a lack of mass production.

This invention was made in order to solve the above-mentioned problems, and is a highly mass-producible non-reflective material that can efficiently dissipate heat without using parts with complicated shapes or increasing the overall scale. The purpose is to obtain termination.

[Means for solving problems]

The non-reflection termination according to the present invention converts a coaxial line into a microstrip line even when the transmission line on the radio wave incidence side is a coaxial line. One side of the radio wave absorber, which had been processed into a tapered shape and placed in close contact with the microstrip line, is now in close contact with the microstrip line.
This eliminates the need for heat dissipation fins by replacing it with a plate-shaped radio wave absorber that is in close contact with a metal lid whose other side has surface contact with another metal body.

[Effect]

One side of the plate-shaped radio wave absorber in this invention is integrated with a metal body with good thermal conductivity through a lid, so the heat generated by absorbing radio waves on the microstrip line is transferred by conduction. It is possible to efficiently release it to the metal body, and the temperature rise is small.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a component configuration diagram, FIG. 2 is a side sectional view (cross section AA), and FIG. 3 is a sectional view (cross section BB).
In the figure, 8 is a coaxial-microstrip line conversion connector, 9 is a microstrip line board, 1
0 is the mounting base of the microstrip line board,
Reference numeral 11 denotes a plate-shaped radio wave absorber placed on the top of the microstrip line board in close contact with the microstrip line board;
2 is a metal lid, and these are the mounting brackets 13
It is attached by screws 14 so as to be in surface contact with the metal body 15.

Next, the operation will be explained.

After passing through the conversion plug 8, the incident radio wave propagates through the microstrip line board 9 in the TEM mode, but when it reaches a region where the radio wave absorber 11 is present, it gradually begins to attenuate. The radio wave absorber 11 has a tapered shape, and the attenuation constant for radio waves propagating on the substrate 9 tends to gradually increase in the direction of propagation of the radio waves. Therefore, heat generation due to absorption of radio waves is uniform. Furthermore, since the radio wave absorber 11 is a flat plate, and one side is in contact with the substrate 9 and the other side is in surface contact with the metal body 15 via the metal lid 12, the generated heat is efficiently dissipated by conduction. It ends up escaping into the metal body 15,
It is possible to prevent the temperature rise of the radio wave absorber 11 and the resulting temperature rise of the substrate 9.

In the above example, the case where the incident radio wave from the coaxial line is converted into the microstrip line mode and then absorbed is explained, but it is also possible to convert it into the balanced strip line (triplate line) mode using a similar shape. A similar effect can be obtained.

Furthermore, if the line on the radio wave incidence side is a microstrip line or a balanced strip line, the structure becomes much simpler because the radio waves can be guided directly to the configuration of the above embodiment without going through a mode conversion plug. .

The radio wave absorber, the mounting base, and the shape A of the lid in FIG. 1 are shown as an example, and the same effects as the above embodiments may be obtained even if the present invention is not limited thereto. In order to reduce the thermal resistance and improve heat dissipation at the contact points between the base board, radio wave absorber, lid, and metal body, it is also more effective to use thermally conductive adhesives, etc. on these contact surfaces. There is a possibility that it will work.

〔Effect of the invention〕

As described above, according to the present invention, the part of the non-reflection termination that functions to absorb radio waves is constructed of a strip line, and the plate-shaped radio wave absorber is closely attached to the metal plate, and heat is radiated by the heat radiation fin. Since the conduction is carried out through both contacts rather than through a single contact, it is possible to achieve a smaller size, lighter weight, and simpler structure, which has the effect of providing an inexpensive product that is suitable for mass production.

[Brief explanation of the drawing]

FIG. 1 is a component configuration diagram of a non-reflection termination according to an embodiment of the present invention, FIG. 2 is a side sectional view of FIG. 1, and FIG.
The figure is a longitudinal sectional view of Fig. 1, Fig. 4 is an external view of a conventional non-reflection termination, Fig. 5, Fig. 6 is a side sectional view of a conventional non-reflection termination, and Figs. 7 and 8 are conventional non-reflection termination. FIG. 3 is an outline diagram of a radio wave absorber used for non-reflection termination. In the figure, 1 is a coaxial connector, 2 is an outer wall, 3 is a heat dissipation fin, 4 is an inner conductor, 5 is a dielectric, 6 and 7 are radio wave absorbers, 8 is a conversion connector, 9 is a board, and 10 is a mounting base. , 11 is a radio wave absorber, 12 is a lid, 13 is a mounting bracket, 14 is a screw, and 15 is a metal body. The same reference numerals in each figure indicate the same or corresponding parts.

Claims (1)

[Claims] 1 The transmission line section is composed of a strip line board,
A plate-shaped radio wave absorber is attached closely to the top so that the amount of radio wave attenuation increases with the distance from the input end, and is further contacted with an external metal body through the metal plate on top of the plate. A non-reflection termination device for microwave high power, featuring: