JPH0729565Y2 - Electromagnetic coupler for high frequency amplifier - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention relates to an electromagnetic coupler for a high-frequency amplifier for supplying a high-frequency input signal to a high-frequency amplifier that supplies high-frequency power to a high-frequency quadrupole accelerator, for example. Is.

[Conventional technology]

To accelerate ions with a high-frequency quadrupole accelerator, high-frequency power of several KW is required. In order to obtain such a large high frequency power from the high frequency amplifier,
It is necessary to input a high frequency signal having a power of about 100W. Further, a high-frequency amplifier used for accelerating ions is required to have a high Q and a mechanically robust structure, and therefore a coaxial resonator (for example, a coaxial λ / 4 cavity) is generally adopted. Is.

A one-turn loop circuit, for example, is used as the configuration of the electromagnetic coupler for the high frequency amplifier for supplying an input signal from the high frequency signal source (not shown) to the high frequency amplifier having the coaxial resonator configuration. In order to efficiently supply the high frequency power from the high frequency signal source to the high frequency amplifier, it is necessary to perform impedance matching between the high frequency amplifier and the high frequency signal source. Therefore, a variable capacitor is provided in series in the loop circuit, and the capacitance of the variable capacitor is adjusted to change the magnitude of the coupling.

FIG. 2 is a schematic sectional view showing an example of the configuration of such a conventional high frequency amplifier.

In FIG. 2, 1 is a first cavity made of metal, and 2 is a second cavity made of metal provided coaxially with the first cavity 1.
3 is a metal partition plate for partitioning the first cavity 1 and the second cavity 2 and has an opening 3a coaxial with the first and second cavities 1 and 2.
have.

Reference numeral 4 denotes an anode made of a metal cap, which is arranged in the first cavity 1 coaxially with the first cavity 1 and has an opening desired in the opening 3a of the partition plate 3. 5 and 6 are
A first grid and a second grid each made of a metal ring are arranged coaxially with the first cavity 1 between the anode 4 and the partition plate 3 in the first cavity 1. Insulation rings 7 and 8 are arranged between the first grid 5 and the second grid 6 and between the second grid 6 and the anode 4, respectively, and insulate the first grid 5, the second grid 6 and the anode 4 from each other. is there.

Reference numeral 9 denotes a cathode made of a metal cylinder, which is the second cavity 2
Inside, it is provided coaxially with the second cavity 2 and one end is inserted into the inside of the anode 4 through the opening 3a of the partition plate 3. Reference numeral 10 denotes a filament inserted inside the cathode 9, one end of which is connected to one end of the cathode 9. Reference numeral 11 denotes a filament power supply connected between the other end of the cathode 9 and the other end of the filament 10, and causes the filament 10 to generate heat and generate thermoelectrons from the cathode 9.

Reference numeral 12 denotes a cylindrical extension of the anode 4, which extends the peripheral wall of the anode 4 in the direction opposite to the partition plate 3. Reference numeral 13 denotes a bottomed cylindrical center conductor arranged coaxially with the anode 4 in the first cavity 1. 14 is a donut-shaped metal plate provided at the opening edge of the central conductor 13, 15 is a donut-shaped metal plate provided at the end edge of the tubular extension 12, and both metal plates 14 and 15 face each other. Then, the cylindrical extension 12 and the central conductor 13 are capacitively coupled. The high voltage is applied to the cylindrical extension 12 as an anode voltage.

Reference numeral 16 is a capacitive coupling portion that capacitively couples the first grid 5 and the partition plate 3, and a high voltage high frequency capacitor is used. Reference numeral 17 is a capacitive coupling portion that capacitively couples the second grid 6 and the partition plate 3, and a high-voltage high-frequency capacitor is used as in the above.

Reference numeral 18 is a donut-shaped metal short plate that closes the first cavity 1, and the outer peripheral edge thereof is in sliding contact with the inner peripheral surface of the first cavity 1.
The inner peripheral edge is in sliding contact with the outer peripheral surface of the central conductor 13. 19 is a donut-shaped metal short plate that closes the second cavity 2,
The outer peripheral edge is in sliding contact with the inner peripheral surface of the second cavity 2, and the inner peripheral edge is in sliding contact with the outer peripheral surface of the cathode 9.

Reference numeral 20 denotes an electromagnetic coupler for inputting a high-frequency signal, which is provided on the peripheral wall of the second cavity 2, and the branch wall portion 21 communicating with the inner wall of the second cavity 2 is connected to the peripheral wall of the second cavity 2. And a cable 22 for signal input is inserted from the branch cylinder portion 21 into the inside of the second cavity 2, and a loop circuit 23 is formed in the second cavity 2 by the cable 22.
After forming the, the tip is branched via the variable capacitor 24
It is connected to the inner surface of 21.

Reference numeral 25 denotes an output electromagnetic coupler provided in the first cavity 1, and a branch cylinder portion 26 communicating with the inside of the first cavity 1 is provided on the peripheral wall of the first cavity 1 to branch the output. The output cable 27 is inserted into the inside of the first cavity 1 through the tubular portion 26, and the first cavity 1 is inserted.
Inside, a cable 27 constitutes a loop circuit 28.

In the high frequency amplifier described above, the high frequency input signal transmitted through the cable 22 is coupled from the loop circuit 23 into the second cavity 2. And the cathode 9, the first grid 5,
An amplified signal is generated in the first cavity 1 by the high frequency amplification effect of the second grid 6 and the anode 4, and this amplified high frequency energy is extracted through the loop circuit 28.

[Problems to be solved by the device]

In the high frequency amplifier as described above, if the frequency of the signal to be amplified is fixed, the variable capacitor 24 is adjusted to change the size of the coupling between the loop circuit 23 and the second cavity 2. Impedance matching between the signal source and the high frequency amplifier can be achieved. However, when the adjustment range of the coupling by the variable capacitor 24 is narrow and the variable range of the frequency of the high frequency amplifier is wide, the adjustment of the variable capacitor 24 alone cannot be sufficient, and some other coupling adjustment means is required. .

As described above, when the variable range of the frequency of the high-frequency amplifier is wide and the adjustment cannot be performed only by adjusting the variable capacitor 24, conventionally, the size of the loop circuit 23 is adjusted by cut-and-try. It was

However, adjusting the loop circuit 23 was extremely troublesome.

Therefore, an object of the present invention is to provide an electromagnetic coupler for a high frequency amplifier, which can have a wide impedance matching range and can easily adjust coupling for that purpose.

[Means for Solving the Problems]

The electromagnetic coupler for a high-frequency amplifier according to claim (1) is provided with a branch cylinder portion communicating with the inside of the cavity, which is provided on a peripheral wall of the cavity forming the outer conductor of the coaxial resonator, and electrically contacts the branch cylinder portion. With the above condition maintained, a metal pipe is inserted into the branch cylinder part so that the pipe can be moved back and forth so that the tip of the pipe faces the cavity.

Further, a hollow conductor having one end located at the base end of the pipe and the other end reaching the tip of the pipe is inserted into the pipe, and the center conductor is arranged inside the hollow conductor.

Further, one end of the loop circuit is connected to the central conductor at the other end of the hollow conductor, the variable capacitor is arranged in the pipe, and the operating portion is exposed to the outside of the pipe, and one end of the variable capacitor is connected to the other end of the loop circuit. In addition to the connection, the other end of the variable capacitor is connected to the pipe.

A coaxial connector is connected to the hollow conductor and the central conductor at the base end of the pipe.

In the electromagnetic coupler for a high-frequency amplifier according to claim (2), the pipe has a cylindrical shape, and the pipe is rotatably inserted into the cylindrical branch cylinder portion.

[Action]

According to the configuration of claim (1), when the pipe is moved back and forth with respect to the branch tube portion, the positional relationship in the cavity of the loop circuit located at the tip of the pipe is changed. As a result, the coupling of the loop circuit changes. Therefore, the change range of the coupling is expanded together with the coupling change due to the change of the capacitance value of the variable capacitor.

According to the structure of claim (2), the positional relationship of the loop circuit in the cavity is also changed by rotating the pipe. As a result, the coupling of the loop circuit changes as described above. Therefore, the change displacement of the coupling is further widened.

〔Example〕

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

FIG. 1 is a schematic cross-sectional view showing the structure of an electromagnetic coupler for a high frequency amplifier according to an embodiment of the present invention, showing the structure of a portion corresponding to the electromagnetic coupler 20 in FIG. The entire structure of the high-frequency amplifier other than the electromagnetic coupler is the same as that of the conventional example, and is not shown.

In FIG. 1, 2 is a second cavity, 3 is a partition plate, and 9 is a cathode, which are the same as in the conventional example and constitute a coaxial resonator.

On the peripheral wall of the second cavity 2 forming the coaxial resonator,
A cylindrical branch cylinder portion 31 communicating with the inside of the second cavity 2 is provided. A flange 31a is integrally formed at the tip of the branch tube portion 31.

Further, a metallic cylindrical extension tube portion 32 having flanges 32a and 32b integrally formed at both ends is connected to the tip of the branch tube portion 31. At this time, the extension tubular portion 32 and the branch tubular portion 31 are connected by, for example, screwing the flange 32a and the flange 31a together while facing each other.

The inner diameter of the extension tubular portion 32 is set to be slightly smaller than the inner diameter of the branch tubular portion 31, and the tip curved portion of the metal contact finger 33 having elasticity held between the flanges 32a and 31a has a branch tubular portion. It is configured so as to project inward from the inner surface of the extension tubular portion 32 within 31.

Then, a circular metal pipe 34 is inserted into the extension cylinder portion 32 and the branch cylinder portion 31 so as to be capable of advancing and retreating and being rotatable, so that the tip of the pipe 34 faces the second cavity 2. .

The outer diameter of the pipe 34 is set to be substantially the same as (slightly smaller than) the inner diameter of the extension cylindrical portion 32, so that the pipe 34 can be advanced and retracted and rotated smoothly without rattling. At this time, the contact finger 33 described above
The tip curved portion is elastically contacted with the outer surface of the pipe 34 inside the branch tube portion 31 to maintain the electrical connection between the branch tube portion 31 and the pipe 34.

In addition, a cylindrical hollow conductor 35 is embedded in the pipe 34, and a center conductor 36 is a hollow conductor inside the hollow conductor 35.
It is housed coaxially with the 35. The hollow conductor 35 has one end located at the base end of the pipe 34 and the other end reaching almost the tip of the pipe 34. At the tip of the hollow conductor 35, one end of the loop circuit 37 is connected to the central conductor 36, and the other end of the loop circuit 37 is connected to the pipe 34 via the variable capacitor 38.

The hollow conductor 35 and the center conductor 36 described above are fixed inside the insulating lid 39 that closes the base end portion of the pipe 34, and a signal is provided on the outside of the lid 39 just opposite to the hollow conductor 35 and the center conductor 36. The input coaxial connector 40 is fixed, and the coaxial connector 40, the hollow conductor 35, and the center conductor 36 are connected to each other.

Further, the variable capacitor 38 is fixed inside the pipe 34, and a rotary shaft 38a for adjusting the capacitance value projects to the outside through the peripheral wall of the pipe 34, and a knob 41 provided on the rotary shaft 38a.
The capacitance of the variable capacitor 38 can be adjusted by rotating the.

Further, a stopper 42 is provided on the outer surface of the pipe 34, and the stopper 42 abuts the flange 32b of the extension tubular portion 32 so that the loop circuit 37 contacts the cathode 9 which is the central conductor in the second cavity 2. It is configured to prevent this.

Further, the loop circuit 37 is configured such that the loop diameter is set to be smaller than the outer diameter of the pipe 34, and the pipe 34 is divided into the branch cylinder portion 31 and the extension cylinder portion.
It is designed so that it can be completely removed from 32.

According to the electromagnetic coupler for the high frequency amplifier of this embodiment, since the pipe 34 having the loop circuit 37 and the variable capacitor 38 is configured to be movable back and forth and rotatable with respect to the branch cylinder portion 31 and the extension cylinder portion 32, The positional relationship of the loop circuit 37 in the second cavity 2 can be changed with two degrees of freedom,
As a result, the coupling can be adjusted, and the adjustment range of the coupling can be widened together with the adjustment of the coupling by changing the capacitance value of the variable capacitor 38. Therefore, the impedance matching range can be widened.

Further, the coupling can be adjusted simply by moving the pipe 34 forward and backward, and the coupling can be easily adjusted.

Also, since the loop diameter of the loop circuit 37 is set smaller than the outer diameter of the pipe 34, the pipe 34 can be removed with the loop circuit 37, the variable capacitor 38, etc. all assembled, and parts replacement and repair are easy. Can be done. Also, when there is a large change in the frequency to be amplified,
The pipe 34, the loop circuit 37, the variable capacitor 38, and the like can be wholly replaced, and the specification change can be easily dealt with.

Since the stopper 42 is provided on the outer surface of the pipe 34, it is possible to prevent the loop circuit 37 from coming into contact with the cathode 9 which is the central conductor in the cavity 2, and thus prevent the failure of the signal source or the like. it can.

Although the pipe 34 is configured to be movable back and forth and rotatable in the above embodiment, it is not necessary to rotate the pipe 34. Also,
If it is not necessary to pull out the pipe 34, loop circuit 37
There is no restriction on the diameter of.

[Effect of device]

According to the electromagnetic coupler for a high frequency amplifier of claim (1), since the pipe having the loop circuit and the variable capacitor is configured to be movable back and forth with respect to the branch cylinder portion, the positional relationship of the loop circuit in the cavity is changed. Therefore, the coupling can be adjusted, and the adjustment range of the coupling can be expanded together with the adjustment of the coupling by changing the capacitance value of the variable capacitor, and thus the impedance matching range can be widened.

Further, the coupling can be adjusted simply by moving the pipe back and forth, and the coupling can be easily adjusted.

According to the electromagnetic coupler for a high frequency amplifier of claim (2), the positional relationship of the loop circuit in the cavity can be changed by rotating the pipe, and the coupling can be adjusted by this. Therefore, it is possible to increase the degree of freedom in coupling adjustment as compared with the first aspect.

[Brief description of drawings]

FIG. 1 is a schematic sectional view showing the construction of an embodiment of the present invention,
FIG. 2 is a schematic sectional view showing the configuration of an example of a conventional high frequency amplifier. 2 ... Cavity, 9 ... Cathode, 31 ... Branch barrel, 32 ...
Extension cylinder, 33 …… Contact finger, 34 …… Pipe,
35 …… Hollow conductor, 36 …… Central conductor, 37 …… Loop circuit,
38: Variable capacitor, 40: Coaxial connector

Claims (2)

[Scope of utility model registration request] 1. A branch cylinder portion provided on a peripheral wall of a cavity forming an outer conductor of a coaxial resonator and communicating with the inside of the cavity, and the branch cylinder portion in an electric contact state. A metal pipe that is inserted into the branching cylinder part so as to be able to move forward and backward and has a tip facing the inside of the cavity, and a hollow that is inserted into the pipe and has one end located at the base end of the pipe and the other end reaching the tip of the pipe A conductor, a center conductor arranged inside the hollow conductor, a loop circuit having one end connected to the center conductor at the other end of the hollow conductor, and a loop circuit arranged in the pipe and having one end connected to the other end of the loop circuit. For a high frequency amplifier including a variable capacitor connected to the pipe, the other end of which is exposed to the outside of the pipe, and a coaxial connector connected to the hollow conductor and the center conductor at the base end of the pipe. Electromagnetic coupler. 2. The electromagnetic coupler for a high frequency amplifier according to claim 1, wherein the pipe has a cylindrical shape and is rotatably inserted into the branch cylinder portion.