JPH09181507A - Bustrate type directivity coupler - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily adjust coupling impedance between connection lines by supporting a capacitive plate rotatably supported oppositely to the surface of a substrate so as to optionally adjust its height from the surface of the substrate in accordance with the rotation of the plate. SOLUTION: The capacitive plate 6 is arranged on the opposite side of the substrate 1 opposed to an earch face 5 and consists of a disk. A fixing male screw shaft 9 is arranged on the center of one face of the plate 6 which is the opposite side of a face opposed to the substrate 1 and engaged with a tap screw type through hole 8 formed on a U-shaped fixing board 7 fixed to the ground face 5 and both the screw parts are screwed up each other. The plate 6 is set up to the same potential as that of the ground face 5. The plate 6 acts as one of a pair of ground faces 5 and the substrate 1 is held between the earth face 5 and the plate 6. Thereby coupling impedance between the connection lines 2, 3 can be adjusted by changing the height of the capacitive plate 6.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a substrate type directional coupler, and more particularly to a substrate type directional coupler used in a low power stage driving an output stage of a transmitter.

[0002]

2. Description of the Related Art Output R of an ultra high frequency or ultra high frequency transmitter
A directional coupler is used to extract the monitor signal from the F signal. Generally, the transmission output of the last stage of this type of transmitter is extremely high, for example, 10 kW, the signal voltage is also extremely high, for example, 700 Vrms, and the signal current is also 1, for example.
5 Arms and this is also very large. Therefore, it is extremely difficult to provide the directional coupler for monitoring the transmission output on the printed circuit board even if the ceramic board is used.

A directional coupler for a signal of, for example, about 10 W, which precedes the transmission output stage, can be formed on a substrate by using a ceramic substrate.

An example of a conventional substrate type directional coupler is shown in FIG.
Shown in U-shaped coupling lines 2 and 3 are formed on the front surface and the back surface of the substrate 1, respectively, and the center (1/4) of each coupling line 2 and 3 is formed.
The linear portions of the wavelength (having a coil property) face each other with the substrate 1 interposed therebetween. The central straight line portions of the coupled lines 2 and 3 perform a coupling action due to mutual induction and mutual capacitance.

However, when transmitting electric power, the coupled line 2
The coupling between 3 and 3, including its impedance characteristics,
It must be balanced to prevent generation of reactive power. Since it is actually necessary to attach and fix the directional coupler to something, it is unavoidable that the ground plane exists relatively close to the coupled lines 2 and 3. This ground plane affects the coupling impedance of the coupling lines 2 and 3. However, using the effect of this ground surface in reverse,
The coupling impedance can be adjusted. As shown in FIG. 4, when the substrate 1 is sandwiched between the two ground planes 5, the coupling impedance can be adjusted by changing the height of the mounting spacer 4 of the substrate 1.

As a means for changing the coupling between the coupled lines, for example, in Japanese Unexamined Patent Publication No. 5-67904 or Japanese Utility Model Laid-Open No. 56-104204, the central portions of the two coupled lines are coupled with a capacitor to couple them. Although methods of changing the degree of coupling between lines have been suggested, all of these methods are used in a receiver and have the characteristic that they can be made small, but they cannot match the coupling impedance.

[0007]

In the conventional method for adjusting the coupling impedance between the coupling lines of the directional coupler shown in FIG. 4, the adjustment is performed while replacing the spacers 4 having different heights. Therefore, the adjustment is discontinuous. Time-consuming,
It was an uneconomical method.

An object of the present invention is to provide a directional coupler whose coupling impedance between coupling lines can be easily adjusted.

[0009]

SUMMARY OF THE INVENTION A substrate type directional coupler according to the present invention comprises a substrate arranged on a ground surface with a predetermined distance, and first and second substrates formed on the front and back surfaces of the substrate, respectively. A second coupling line, a rotatably-supported capacitance plate arranged facing the surface of the substrate, and a surface of the capacitance plate that supports the capacitance plate and rotates in response to the rotation of the capacitance plate. And a support means whose height is adjustable.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The operation of the present invention is as follows.
By making one of the ground planes sandwiching the pair of coupling lines formed on the front surface and the back surface of the substrate rotatable, the height can be easily adjusted.

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

FIG. 1 is a perspective view showing the construction of an embodiment of a directional coupler according to the present invention, FIG. 2 is a side view thereof, and FIG.
The same parts as 4 and 4 are indicated by the same reference numerals.

In FIG. 1, a substrate 1 is basically the same as that shown in FIG. 3, and U-shaped coupling lines 2 and 3 are provided on the front and back surfaces thereof. The substrate 1 is mounted on a ground plane 5 via a spacer 4 of fixed height.

As shown in FIG. 2, a capacitance plate 6 is provided on the opposite side of the ground plane 5 of the substrate 1. The capacitance plate 6 is a circular plate, and a mounting male screw shaft 9 is provided at the center of the surface opposite to the surface facing the substrate 1 to form a male screw, which is mounted on the ground surface 5. It is fitted in a tap screw type through hole 8 provided in the V-shaped mounting base 7, and the screw portions are screwed together. Therefore, the capacitance plate 6 has the same potential as the ground plane 5.

The capacitance plate 6 serves as one of the pair of ground planes in FIG. 4, and the substrate 1 is sandwiched between the ground plane 5 and the capacitance plate 6 in FIG. Therefore, by changing the height of the capacitance plate 6, the coupling impedance of the coupling lines 2 and 3 can be adjusted.

Since the capacity plate 6 is fitted in the tap hole 8 of the mounting base 7 by the male screw shaft 9 for mounting, the capacity plate 6 can be adjusted in its height infinitely finely by rotating it. Therefore, the coupling impedance of the coupling lines 2 and 3 can be easily and continuously adjusted.

When the adjustment is completed, another nut (not shown) can be inserted into the mounting male screw shaft 9 of the capacity plate 6 and fixed in the form of a double nut with the tap hole 8.

[0018]

As described above, according to the present invention, the coupling impedance between the coupling lines of the directional coupler can be easily and continuously adjusted by rotating the capacitance plate.

[Brief description of the drawings]

FIG. 1 is a perspective view of an embodiment of the present invention.

FIG. 2 is a side view of an embodiment of the present invention.

FIG. 3 is a top view of a substrate type directional coupler.

FIG. 4 is a side view of an example of a conventional directional coupler.

[Explanation of symbols]

 1 substrate 2, 3 coupling line 4 spacer 5 ground plane 6 capacitance plate 7 mounting base 8 tap hole 9 mounting male screw shaft

Claims (2)

[Claims] 1. A substrate arranged on the ground plane at a predetermined distance, first and second coupling lines formed on the front and back surfaces of the substrate, respectively, and facing the front surface of the substrate. A capacity plate disposed and rotatably supported; and a support means for supporting the capacity plate and adjusting the height of the capacity plate with respect to the surface of the substrate according to the rotation of the capacity plate. Substrate type directional coupler. 2. The supporting means has a through hole provided with a tap screw, and a male screw portion is provided on a central axis of the capacitance plate, and the tap screw of the through hole and the central axis of the through hole are provided. The substrate type directional coupler according to claim 1, wherein the male screw portion is screwed together.