JPH06177614A - Impedance compensating circuit - Google Patents

Abstract

PURPOSE:To easily adjust an impedance of a coaxial feeder. CONSTITUTION:A compensating circuit 3 is in a ring shape and its outside comes into contact with the inside of the external conductor 1 of the coaxial feeder. The compensating circuit 3 are fixed to two mounts 4 and 5 with compensating circuit fixing screws 10 and 11 through a slit 1a formed in the coaxial feeder external conductor 1 so that the long axis is in the axial direction of the coaxial feeder external conductor 1. The mounts 4 and 5 are arranged outside the coaxial feeder external conductor 1 so as to cover slits 1a and 1b and fixed to the coaxial feeder external conductor 1 with bands 6 and 7 and fixing screws 8 and 9. When the mounts 4 and 5 are moved along the slits 1a and 1b, the compensating circuit 3 moves along the inside of the coaxial feeder external conductor 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an impedance compensation circuit, and more particularly to a UHF, VHF television broadcasting device and FM.
The present invention relates to an impedance compensation circuit for a coaxial feeder used in a radio broadcasting device.

[0002]

2. Description of the Related Art Conventionally, in an impedance compensation circuit for a coaxial feed line, as shown in FIGS. 3A to 3C, a coaxial feed line inner conductor 2 that constitutes a coaxial feed line with a coaxial feed line outer conductor 1 is used. Compensation circuit 12 with compensation circuit fixing screw 13,
It is attached with 14.

The compensating circuit 12 changes the capacitance of the coaxial feed line to achieve impedance matching. That is, in the coaxial feed line inner conductor 2, the compensation circuit 1
At the fixed position of 2, the distance from the outside of the compensation circuit 12 to the inside of the coaxial feed line outer conductor 1 is shorter than the distance from the outside of the coaxial feed line inner conductor 2 to the inside of the coaxial feed line outer conductor 1 at other positions. The capacitance of the impedance of the coaxial feed line transmission line changes, and impedance matching is achieved.

Therefore, the compensating circuit 12 is fixed at the optimum position where the impedance matching of the coaxial feed line inner conductor 2 can be obtained. The compensation circuit 12 is fixed to the coaxial feed line inner conductor 2 by the compensation circuit fixing screws 13 and 14 screwed into the compensation circuit fixing screw holes 12a and 12b of the compensation circuit 12, respectively.

[0005]

In this conventional impedance compensation circuit for a coaxial feed line, the coaxial feed line inner conductor 2 is removed from the coaxial feed line outer conductor 1 until the optimum position for impedance matching is determined. Since the fixed position of the compensation circuit 12 is changed and the coaxial feed line inner conductor 2 is inserted again into the coaxial feed line outer conductor 1, it is necessary to repeat the work while checking the characteristics of the coaxial feed line. There is a problem that it takes time.

Therefore, an object of the present invention is to provide an impedance compensating circuit capable of easily adjusting the impedance matching of the coaxial feeder line.

[0007]

An impedance compensating circuit according to the present invention is an impedance compensating circuit for a coaxial feed line composed of an outer conductor and an inner conductor, the impedance compensating circuit being provided in contact with the inner side of the outer conductor. It has a ring member for achieving impedance matching of the coaxial power supply line, and a mounting member for mounting the ring member on the outer conductor so as to be movable in the axial direction of the coaxial power supply line.

[0008]

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

FIG. 1A is a perspective view of an embodiment of the present invention, and FIG. 1B is a sectional view of an embodiment of the present invention.
2A is a perspective view of the coaxial feed line outer conductor 1 of FIG. 1, FIG. 2B is a perspective view of the compensation circuit 3 of FIG. 1, and FIG. It is a perspective view of the mount 4.

In these figures, the coaxial feed line outer conductor 1
The compensating circuit 3 for impedance matching in the coaxial feed line composed of the inner conductor 2 and the coaxial feed line inner conductor 2 has a ring shape, and its outer circumference is in contact with the inner side of the coaxial feed line outer conductor 1.

As a result, in the portion where the compensation circuit 3 is arranged in the coaxial feed line, the distance from the outside of the coaxial feed line inner conductor 1 to the inside of the compensation circuit 3 is the coaxial feed from the outside of the coaxial feed line inner conductor 2 at another position. Since the distance is shorter than the distance to the inside of the outer conductor 1 of the electric wire, the capacitance of the impedance of the coaxial feed line transmission line changes, and impedance matching is achieved.

The compensating circuit 3 has slits 1a, 1b (slit 1b not shown) provided in the coaxial feed line outer conductor 1 such that the major axis thereof is in the axial direction of the coaxial feed line outer conductor 1.
Via the compensation circuit fixing screws 10 and 11 to the two mounts 4 and 5. These mounts 4, 5
Is arranged outside the coaxial feed line outer conductor 1 so as to cover the slits 1a and 1b, and is fixed to the coaxial feed line outer conductor 1 by the bands 6 and 7 and the fixing screws 8 and 9.

Compensation circuit 3 and mounts 4 and 5 are provided with compensation circuit fixing screws 10 and 11 for fixing the compensation circuit 3 to the mounts 4 and 5, respectively.
a, 3b, 4a and 5a are provided respectively. These compensating circuit fixing screw holes 3a, 3b, 4a, 5a are each provided with a thread groove, and particularly, the compensating circuit fixing screw holes 3a, 3a.
b are opened at positions facing each other.

The compensation circuit 3 is fixed to the outer conductor 1 of the coaxial feed line in the following manner. First, the slits 1a, 1 are aligned with the compensation circuit fixing screw holes 3a, 3b of the compensating circuit 3 and the compensation circuit fixing screw holes 4a, 5a of the mounts 4, 5.
via b.

Thereafter, the compensation circuit fixing screws 10 and 11 are screwed into the compensation circuit fixing screw holes 4a and 5a of the mounts 4 and 5, and the compensation circuit fixing screws 10 and 11 are inserted into the compensation circuit fixing screw holes 4a and 5a and the slits. It is screwed into the compensation circuit fixing screw holes 3a and 3b of the compensation circuit 3 via 1a and 1b. As a result, the compensation circuit 3 is fixed to the mounts 4 and 5 by the compensation circuit fixing screws 10 and 11, and the compensation circuit 3 is fixed to the coaxial feed line outer conductor 1.

The slits 1a and 1b are for changing the position of the compensation circuit 3 from the outside. Since the compensating circuit 3 is fixed to the mounts 4 and 5, if the mounts 4 and 5 are moved along the slits 1a and 1b, the compensating circuit 3 moves along the inside of the coaxial feed line outer conductor 1. By setting the compensation circuit 3 from the outside, it is possible to easily determine the optimum position where impedance matching is achieved.

In this way, the compensation circuit 3 is provided with the slits 1a,
The fixing position of the compensation circuit 3 can be set from outside by fixing the coaxial feeding line outer conductor 1 through the mounts 4 and 5, the bands 6 and 7, and the compensation circuit fixing screws 10 and 11 through 1b. Therefore, it is not necessary to attach / detach the coaxial feed line inner conductor 2 to / from the coaxial feed line outer conductor 1 each time the compensation circuit is adjusted as in the conventional example. Therefore, the impedance matching of the coaxial feed line can be easily adjusted. You can

In one embodiment of the present invention, the compensating circuit 3 is mounted on the mounts 4, 5, the bands 6, 7 and the compensating circuit fixing screw 10,
It is fixed to the outer conductor 1 of the coaxial power supply line by 11,
The mounting member for fixing the compensation circuit 3 may be a cylindrical member that contacts the outer side of the coaxial feed line outer conductor 1, but is not limited thereto.

[0019]

As described above, according to the present invention, the ring member for contacting the impedance of the coaxial feed line is provided in contact with the inner side of the outer conductor, and the ring member is attached to the coaxial feed line in the axial direction. It is possible to easily adjust the impedance matching of the coaxial feed line by movably attaching the coaxial feed line to the outer conductor.

[Brief description of drawings]

1A is a perspective view of an embodiment of the present invention, and FIG. 1B is a sectional view of the embodiment of the present invention.

2 (a) is a perspective view of the outer conductor of the coaxial feeder line of FIG. 1,
(B) is a perspective view of the compensation circuit of FIG. 1, and (c) is a perspective view of the mount of FIG. 1.

3A is a perspective view of a conventional example, FIG. 3B is a sectional view of the conventional example, and FIG. 3C is a perspective view of a compensation circuit of the conventional example.

[Explanation of symbols]

 1 Coaxial feeding line outer conductor 1a Slit 2 Coaxial feeding line inner conductor 3 Compensation circuit 3a, 3b Compensation circuit fixing screw hole 4,5 Mount 4a, 5a Compensation circuit fixing screw hole 6,7 Band 10,11 Compensation circuit fixing screw

Claims (2)

[Claims] 1. An impedance compensating circuit for a coaxial power feed line composed of an outer conductor and an inner conductor, wherein the ring member is provided in contact with the inner side of the outer conductor and serves to achieve impedance matching of the coaxial power feed line. And an attachment member for attaching the ring member to the outer conductor so as to be movable in the axial direction of the coaxial power supply line. 2. The mounting member has first and second elongated holes provided in the outer conductor in parallel to each other with their major axes parallel to the axis of the coaxial feeder line and provided to face each other from the outside of the outer conductor. First and second mount members that cover, fixing members that fix the first and second mount members to the outer conductor, and screws that fix the ring member to the first and second mount members, respectively. The impedance compensation circuit according to claim 1, wherein the impedance compensation circuit comprises a member.