JP2537875Y2 - Stub structure of electric stub tuner - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to an improvement in a stub structure of an electric stub tuner used for a microwave circuit.

[Conventional technology]

FIG. 2 is a schematic view of a main part of a conventional stub tuner. In the figure, 1 is a waveguide for transmitting microwaves, 2 is a metal stub of a round bar having a rounded tip, and usually 1 to 4 are, for example, λg / 8 (λg: average tube diameter). (Wavelength) at a distance from the waveguide wall. Reference numerals 3 and 4 denote rotary linear motion converting mechanisms. Reference numeral 3 denotes a rack fixed to the stub 2. Reference numeral 4 denotes a pinion for interlocking the rack 3. Reference numeral 5 denotes a motor that applies a rotational force to the pinion 4. By letting
The stub 2 moves linearly and descends to the position shown by the dotted line in FIG.

Here, for example, when performing impedance matching manually, a forward or reverse rotation signal is given to the motor 5 so that the reflected power amount displayed on a power meter (not shown) is minimized, and the insertion depth of the stub 2 is reduced. I am adjusting. That is, impedance matching is performed by utilizing the change in the capacitance between the stub 2 and the waveguide 1.

On the other hand, as shown in FIG. 3, a stub tuner in which the rotary linear motion conversion mechanism is changed is considered. That is, instead of the rack and pinion, a ball screw nut (hereinafter simply referred to as a nut) 7 is attached to the opening of the cylindrical metal housing 6, and the ball screw screw shaft (hereinafter simply referred to as the screw shaft). ) 8 is screwed into the nut 7.

Reference numeral 9 denotes a joint for connecting the bottom of the housing 6 and a metal stub 12 of a round bar, reference numeral 10 denotes a rotation preventing rod vertically mounted on the waveguide 1, and reference numeral 11 denotes a rotation preventing prevention rod 10 which is inserted and fitted. The stopper is a stopper for preventing rotation and is fixed to a nut 7. The nut 7, the screw shaft 8, the rotation preventing rod 10, and the rotation preventing rod receiver 11 constitute a rotation linear motion conversion mechanism.

Reference numeral 5 denotes a motor, which is connected to the upper end of the screw shaft 8 as shown in the drawing. By rotating the motor 5, the position of the screw shaft 8 does not change, and the housing 6 and the stub 2 are prevented from rotating. It moves linearly along 10 and descends to the position shown by the dotted line in FIG.

[Problems to be solved by the invention]

Since the length of only the stub of the conventional stub tuner and the total length of the stub and the portion attached to the stub are required to be at least twice as long as the maximum stroke length L of the stub, the device becomes larger, Since the stub and the portion attached to the stub are made of metal such as copper or brass, the load on the drive system including the motor is increased, and there is a problem that their life is shortened. In addition, a driving motor needs to have a high output, and there is a problem that the cost is high.

[Means for solving the problem]

In order to solve the above problems, the present invention sets the stub length of an electric stub tuner used for a microwave circuit to a maximum stroke length necessary for impedance matching, and opens one end of the stub. A hollow portion is provided in the longitudinal direction to form a tube over the entire length of the stub, a nut is attached to the cylindrical opening, a screw having the same length as the stub is screwed to the nut, and the position of the screw is changed. By rotating the screw without changing it, the screw is housed in the hollow portion while the rotational movement of the screw advances and retreats the stub.

〔Example〕

FIG. 1 is a schematic view of a main part of the stub tuner of the present invention, and the same components as those in FIG. 3 are denoted by the same reference numerals. In the figure, reference numeral 22 denotes a stub, which is formed by cutting out a central portion of a round bar made of copper, brass, or the like having substantially the same length as its maximum stroke length L and forming it into a cylindrical shape having an appropriate thickness. Alternatively, it is manufactured by attaching a cap with a rounded tip to a pipe such as copper or brass. The nut 7 is attached to the opening of the stub 22 and the screw shaft 8 having substantially the same length as the maximum stroke length L of the stub is screwed to the nut 7.

A rotation-preventing rod receiver 11 inserted into a rotation-preventing rod 10 attached to the waveguide 1 is fixed to the nut 7 and rotates the motor 5 connected to the upper end of the screw shaft 8. As a result, the stub 22 linearly moves along the rotation preventing rod 10 without changing the position of the screw shaft 8, and
It descends to the position shown by the dotted line in the figure.

Instead of the ball screw, a normal moving screw such as a bolt or a nut can be used.

[Effect of the invention]

As described above, according to the present invention, since the stub is formed in a cylindrical shape and has a length substantially equal to the maximum stroke length of the stub, the size and weight of the device can be significantly reduced. Greatly reduces the load on the drive system,
Since the service life is prolonged, the number of parts can be reduced, and a motor having a smaller power can be employed. Therefore, the value in practical use is high, such as reduction in cost.

[Brief description of the drawings]

FIG. 1 is a schematic view of a main part of the stub tuner of the present invention, FIG.
FIG. 3 and FIG. 3 are schematic views of a main part of a conventional stub tuner. 1 ... waveguide, 5 ... motor, 22 ... stub.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Shinji Yamamoto 2-1-1-11 Tagawa, Yodogawa-ku, Osaka-shi, Osaka Daihen Co., Ltd. (56) References JP-A-61-1101 (JP, A) 59-175747 (JP, U)

Claims (1)

(57) [Scope of request for utility model registration] In a stub structure of an electric stub tuner used for a microwave circuit, one end of a stub is opened to provide a hollow portion in a longitudinal direction to form a tube, and a nut is attached to the cylindrical opening. By screwing a screw on the nut and rotating it without changing the position of the screw,
A stub structure of an electric stub tuner in which the screw is housed in the hollow portion while the rotational movement of the screw moves the stub forward and backward.