JPS6087501A - Waveguide type terminator - Google Patents

Abstract

PURPOSE:To press and fix a radio wave absorbing body in a waveguide under a proper pressure by pressing and fixing the radio wave absorbing body to the wall of the waveguide through the use of a spring washer and a screw whose head shape is coincident with the shape of the surface of said radio wave absorbing body. CONSTITUTION:The radio wave absorbing body 3 in the waveguide 1 is pressed and fixed to the inner wall of the waveguide 1 by the head of the screw 5 whose head tip is tapered so as to be mated to the slope of said radio absorbing body 3. The screw 5 is tightened from the outer part of the waveguide 1 by using the spring washer 6 and a nut 7 so that the radio wave absorbing body 3 is pressed and fixed to the inner wall of the waveguide 1 at a proper pressure. In the radio wave absorbing body 3, the head of the screw 5 is allowed to contact closely and fixed to the radio wave absorbing body 3 at a proper pressure through the elasticity of the spring washer 6 at all times.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field to Which the Invention Pertains] The present invention relates to an improvement in a waveguide type terminator used at extremely low temperatures, where the temperature of the atmosphere in which it is placed changes significantly, for example.

(Description of the prior art) In a waveguide type terminator used in an environment where the temperature of the atmosphere changes significantly, the radio wave absorber inside the waveguide moves or comes off, causing high frequency It is desirable to reliably support and fix the radio wave absorber to the waveguide wall so as not to cause deterioration of characteristics.

In conventional waveguide type terminators, the radio wave absorber is attached to the waveguide wall with adhesive, or a hole is made in a part of the radio wave absorber and screwed to the waveguide wall. This supports and fixes the radio wave absorber within the waveguide. However, in environments where the temperature of the atmosphere changes significantly, when using a conventional waveguide type terminator, the coefficient of thermal expansion of each material that makes up the waveguide type terminator Due to these differences, it is possible to prevent peeling between the waveguide wall and the adhesive, or between the adhesive and the radio wave absorber, and to ensure that the radio wave absorber is supported and fixed within the waveguide. Can not.

In addition, in a waveguide type terminator that has a structure in which a hole is drilled in the radio wave absorber and screwed to the waveguide wall, the radio wave absorber has a different coefficient of thermal expansion than the screw part, so the radio wave absorber and the screw part have different coefficients of thermal expansion. This has the disadvantage that a gap is created between the device and the screw, causing the screw to become loose, causing the radio wave absorber to shift, resulting in a change in high frequency characteristics.

[Purpose of abolishing Ming]

The present invention solves the above-mentioned drawbacks, and provides a waveguide that can reliably support and fix a radio wave absorber within a waveguide even if the temperature of the atmosphere in which it is placed changes significantly, and that does not cause deterioration of high frequency characteristics. The purpose is to provide a tube-type terminator.

[Features of the invention]

A radio wave absorber placed in a waveguide whose one end is electrically short-circuited is screwed so that the shape of the tip of the rabbit expands to match the shape of the surface of the radio wave absorber, or the external dimensions of both ends are It is characterized by being crimped and fixed to the waveguide wall using NANDs with different numbers and a spring washer used in combination with the NANDs.

[Explanation based on examples] The invention will be explained by way of example in the accompanying drawings.

FIG. 1 is a sectional view showing the structure of a first embodiment of the present invention. The radio wave absorber 3 in the waveguide 1 is crimped to the inner wall of the waveguide 1 by the head of a screw 5 whose tip has a widened head along the slope of the radio wave absorber 3. This screw 5 is used to press the radio wave absorber 3 onto the inner wall of the waveguide 1 with appropriate pressure.
For fixing, a spring washer 6 and a nut 7 are tightened from the outside of the waveguide 1. In this waveguide type terminator, even if the temperature of the atmosphere in which it is placed changes significantly and the radio wave absorber 3 contracts or expands, the spring property of the spring washer 6 allows the head of the screw 5 to remain fixed. Always adhere to the radio wave absorber 3 with appropriate pressure.

FIG. 2 is a sectional view showing the structure of a second embodiment of the present invention.

In this structure, the radio wave absorber 3 is similarly crimped and fixed inside the waveguide 1 with one screw 5, a leaf spring (spring washer) 6, and a nut 7, but the head of the screw 5 is attached to the waveguide. Touches the wall of 1.

FIG. 3 is a sectional view showing the structure of a third embodiment of the present invention.

This example has a structure in which a radio wave absorber 3 is crimped and fixed inside a waveguide 1 using a nut 7 having different outer dimensions at both ends, a spring washer 6, and a screw 5.

〔Effect of the invention〕

As explained above, even if the temperature of the atmosphere in which it is placed changes significantly due to extremely low temperatures, etc., the radio wave absorber is always guided at an appropriate pressure due to the spring properties of the spring washer and the screw heads or NANDs with different external dimensions at both ends. It can be crimped and fixed inside the wave tube. Furthermore, this structure has the advantage of 'A' in that it is not necessary to make a hole in the radio wave absorber, so there is no acid leakage of the radio wave absorber when making the hole, and there is no need for drilling work.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of a waveguide type terminator according to a first embodiment of the present invention. FIG. 2 is a cross-sectional view of a waveguide type terminator according to a second embodiment of the present invention. FIG. 3 is a cross-sectional view of a waveguide type terminator according to a third embodiment of the present invention. 1... Waveguide, 3... Radio wave absorber, 4... Screw,
5...Screw with a widened head end, 6...Spring washer, 7...Nand, 8...Nand with different external dimensions at both ends. Patent applicant NEC Corporation,. Agent: Patent Attorney Naotaka Ide, Shoulder: 1, Figure: 2, Mouth: 3:

Claims (1)

[Claims] +11 In a waveguide type terminator in which a radio wave absorber having a surface inclined with respect to the wall surface of the waveguide is disposed inside a waveguide, the surface in contact with the radio wave absorber is A screw or nut formed in an inclined shape that matches the slope of the surface of the radio wave absorber, and a spring washer through which the screw or the screw screwed into the nut slides through, allow the radio wave absorber to be attached to the waveguide. A waveguide type terminator characterized by being crimped onto the wall surface.