JPS604302A - Expansible waveguide - Google Patents

Abstract

PURPOSE:To prevent the leak of radio waves and to reduce the variation of electric characteristics for sliding by providing an element, which has a filtering characteristic, on the outside wall of the front end, which is inserted into an outside waveguide, of an inside waveguide. CONSTITUTION:A fin-type resonance element 4 is provided as the element having a filtering characteristic on the outside wall of the end part, which is inserted into an outside waveguide, of an inside waveguide 2, and one of long sides facing each other and one of short sides facing each other of the inside waveguide are cut in positions, which are a 1/4 of the transmission wavelength in the waveguide distant from the front end of the waveguide, to constitute an equivalent 1/4-wavelength transformer. By this element having a filtering characteristic, the leak of radio waves is prevented, and impedance matching is attained by the 1/4- wavelength transformer. Thus, the variation of electric characteristics at the time, when the waveguide is slid, is suppressed. A corrugated filter element or a waffle-type filter element may be used as the element having a filtering characteristic.

Description

DETAILED DESCRIPTION OF THE INVENTION This invention is intended to alleviate the tensile stress or compressive stress in the waveguide axis direction caused by thermal expansion and contraction of an antenna feeding commercial waveguide system or earthquakes, or for measurements such as phase adjustment. The present invention relates to the structure of a telescopic waveguide used for commercial purposes.

A conventional auxiliary waveguide has a structure shown in FIG.

In Figure 1, (+1 is an external waveguide, (2) is an internal waveguide, and the internal waveguide (2) can be expanded and contracted by sliding the inner metal of the external waveguide (1). It has a structure.Also.

The thickness of the tip of the outer waveguide (11) of the inner waveguide (2) that is inserted into the outer waveguide (11) contains the radio wave propagating inside the outer waveguide (1) and the inner waveguide (2). The taber (3) is provided in consideration of impedance matching of radio waves propagating inside the metal and mode conversion characteristics.

However, in the above-mentioned conventional telescopic waveguide, the externally fitted waveguide (1
Radio waves may easily leak from the gap between the inner wall of the waveguide (1) and the outer wall of the inner waveguide (2), and the VSWR% and L'O8S characteristics may change due to changes in the wall contact condition during sliding. Especially when used on a large-capacity communication line, crosstalk to adjacent lines,
This had the drawback of leading to deterioration of line quality due to an increase in noise figure.

On the other hand, if the distance 1'J between the walls of the outer waveguide (11 and the inner waveguide (2) is made smaller in order to prevent the above-mentioned radio wave leakage, etc., There was a point in time when the sliding properties of the waveguide deteriorated and the expansion and contraction function was impaired, resulting in a loss of practicality.

This invention is a telescopic waveguide characterized by providing an element having a one-wave characteristic on the outer wall of the end of the inner waveguide on the side to be inserted into the outer waveguide, and the element has a fin shape. Resonant element, Waffle type e-wave element or corrugate (Oo
RW wave leakage is achieved by blocking the propagation of radio waves to the gap between the fitting part of the outer waveguide and the inner waveguide using a T4 wave element (rrugatθ) type T4 wave element.

This suppresses changes in VSWR characteristics and Loss% properties, and completely improves the above-mentioned drawbacks and separation points of conventional stretchable waveguides.

The present invention will be described in detail below based on FIG.

FIG. 2 is a diagram showing an embodiment of the present invention, in which an interpolated waveguide (2
) is a schematic structural diagram of fitting of a telescopic 11-wave groove in which a fin-shaped resonant element (4) is provided on the outer wall of the end portion.

FIG. 3 is an end structural diagram of an interpolated waveguide (2) provided with a fin-shaped resonant element (4) as an element having p-wave characteristics.

The fin-shaped resonant element provided on the outer wall of the end of the inner waveguide shown in FIGS. Fin-shaped resonant element (4)
Electrical intelligence effect is obtained at the position of , radio wave leakage, VSWR
Changes in characteristics and LosB characteristics are suppressed.

FIG. 4 shows another embodiment of the present invention, in which a Wuzzle-type f-wave element (5) is used in place of the fin-type resonant element (4) shown in FIG. 2 and the coffin 3.

The Watsufuru-shaped e-wave resistor (5) is dimensioned to have good band rejection characteristics and prevents radio wave propagation into the wall gap between the outer waveguide and the inner waveguide. The above effects suppress radio wave leakage, changes in VSWR characteristics and Loss characteristics, and improve the drawbacks and difficulties of conventional telescopic waveguides.

FIG. 5 shows still another embodiment of the present invention, in which a corrugated I-J wave element (6), which is a modification of the Watsuful F-wave element (5), is fully used as an element having P-wave characteristics. .

The effect of the corrugated r-wave element (6) is the Watsuful type shield.
It is exactly the same as the wave element (5).

As described above, the present invention provides a telescopic waveguide characterized in that the outer wall at the end of the interpolated waveguide is entirely provided with a resistor having P-wave characteristics. This completely prevents the propagation of radio waves into the wall gap between the outer waveguide and the inner waveguide by short-circuiting or blocking the radio waves. Therefore, the slidability of the inner waveguide with respect to the outer waveguide is not completely lost.

This is an extremely effective structure that can suppress radio wave leakage, VSWR characteristic changes during sliding, and Loss characteristic changes.

[Brief explanation of drawings]

FIG. 1 is a schematic structural diagram of a conventional telescopic waveguide, and FIG. 2 is a schematic structural diagram of a fitting part of a telescopic waveguide showing an embodiment of the present invention.
Figure 3 is a structural diagram of the end of an interpolated waveguide equipped with a fin-shaped resonant element, Figure 4 is a structural diagram of the end of an interpolated waveguide equipped with a Watsufuru-shaped P-wave element, and Figure 5 is a corrugated waveguide. It is an end structural diagram of an interpolated waveguide provided with a four-wave element (Kawama external fitting waveguide,
(2) is an interpolation waveguide, (3) is a Taber, (4) is a fin-type resonant element, (5) is a waffle-type f-wave element, and (6) is a corrugated-type p-wave element. Note that the same or corresponding parts in FIG. 9 are indicated by the same reference numerals.゛－－゛°－Acting agent Masuo Oiwa Figure 1 Figure 2! Figure 4 Figure 5

Claims (1)

[Claims] iii. In a telescopic waveguide configured by inserting an inner waveguide into an outer waveguide and capable of sliding in the tube axis direction, the inner waveguide on the side inserted into the outer waveguide is A telescopic waveguide characterized in that an element having f5 wave characteristics is provided on the outer wall of the tip end of the inserted waveguide. (21! Expandable waveguide according to claim 11 using a fin-shaped resonant element as an element having F-wave characteristics.
f', Le) type one-wave element
The telescopic waveguide according to item 1. (4) Corrugate (Oor
rugatθ) type one-wave element is used.
The telescopic waveguide according to item 11.