JPH04196712A - Pulse generator - Google Patents

Abstract

PURPOSE:To attain quick rise at a high voltage, to widen a pulse width and to attain excellent flatness by selecting the number of windings of a conductor per an axial unit length constituting a spiral line larger at an input terminal connected to a switching element and smaller toward an output terminal connected to a load. CONSTITUTION:A center conductor 73 and an intermediate conductor 72 in spiral wound on an insulator 4 are disposed in the inside of a conductor cylinder 71 to form a double spiral line. The number of windings per unit length of the spiral conductor is largest at the input terminal of the line connected to the switching element and smaller toward the load end. Thus, since the inductance of the input section of a bloom line is large, the high frequency component of a travelling wave propagated through the intermediate conductor 72 is reduced, and no overshoot appears in a step wave propagated through the bloom line. Thus, the flatness of the rectangular wave applied to a load 5 is improved.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Field of Industrial Application) The present invention relates to a pulse generator for supplying high-voltage rectangular wave pulses to an electron gun, klystron, or the like.

(Prior Art) Conventionally, as a circuit for generating high voltage pulses, a method of serializing pulse shaping circuits such as Blumlein type and stackline type is known.

FIG. 3 shows a rectangular wave pulse generator using a Blumlein 6, in which a thyratron 3 is used as a switching element. When such a Blumlein is used, the impedance between the first conductor 61 and the second conductor 62 is 21, the impedance between the second conductor 62 and the third conductor 63 is 22, and the load is If the impedance of the conductor 62 is R, then if R/2=Z,=22, a rectangular wave pulse of the same voltage as when the conductor 62 is charged using the charging power source 1 can be obtained at the output.

(Problem to be solved by the invention) By the way, in order to increase the efficiency of particle acceleration using a high-frequency amplifier tube such as a klystron, it is necessary to increase the voltage of the pulse to make the rise faster, and to improve the flatness of the rectangular wave. There is.

However, as mentioned above, by increasing the pulse generation voltage,
Furthermore, when a Blumlein type pulse forming line is used to shorten the rise time, the following problems arise. That is, in the conventional Blumlein type pulse forming line, the pulse width is determined by the round trip propagation time of the line, so in order to obtain a pulse with a wide pulse width of several hundred ns, for example, a Blumlein line with a line length of several tens of meters is required. A line is required. Furthermore, in order to match the impedance of the Blumlein line with a high impedance load such as a klystron, the width of the hollow portion of the Blumlein line must be made very large. For these reasons, in order to supply a wide pulse voltage to a high load impedance, a huge Blumlein line is required, which is extremely difficult to install in practice.

One method for solving this problem is to construct the Blumlein line with a conductor cylinder and a double spiral conductor installed inside the cylinder. When this method is used, the surge impedance of the line increases, and it is possible to match the load with a relatively small line.

However, this method had the following problems. That is, a switching element such as a thyratron has a stray capacitance relative to the ground depending on its shape. Therefore, when affected by this stray capacitance, the output waveform becomes distorted as shown in FIG. 4, and the flatness of the rectangular wave deteriorates.

The present invention was proposed to solve the above-mentioned problems, and its purpose is to quickly rise at high voltage,
Another object of the present invention is to provide a pulse generator capable of supplying a rectangular wave pulse with a wide pulse width and good flatness.

[Structure of the Invention] (Means for Solving the Problems) The present invention provides a pulse generator that generates a rectangular wave pulse using multiple spiral lines arranged in a conductive cylinder and a switching element, in which the spiral line is configured. The number of turns per unit length in the axial direction of the conductor is large at the human power end connected to the switching element, and becomes smaller toward the output end connected to the load.

(Function) In the pulse generator of the present invention, since the number of turns per unit length in the axial direction of the conductor constituting the spiral line is large at the input end connected to the switching element, the inductance of the human power section is large. Therefore, it is possible to reduce the high frequency component of the traveling wave propagating to the intermediate conductor when the switch is operated. As a result, overshoot occurring in the step wave can be prevented, and the flatness of the rectangular wave applied to the load can be improved.

(Example) Hereinafter, an example of the present invention will be specifically described with reference to FIGS. 1 and 2. Incidentally, the same members as those of the conventional type shown in FIG. 3 are given the same reference numerals, and the description thereof will be omitted.

In the present embodiment, as shown in FIG. A spiral track is formed. The number of turns per unit length of these spiral conductors is greatest at the input end of the line;
It is configured so that it decreases toward the load end.

The total lengths of the center conductor 73 and the intermediate conductor 72 along the spiral are substantially equal to each other.

The pulse generator of this embodiment having such a configuration operates as described below. That is, the intermediate conductor 72 charged through the resistor 2 by the charging power source 1 is grounded by closing the switch 8.

Then, a step wave having a rise time determined by the characteristics of the switch 8 is input to the distributed constant circuit composed of the conductor cylinder 71 and the intermediate conductor 72. At this time, high frequency resonance occurs between the capacitance that the switch 8 has with respect to the ground and the inductance of the lead wire connecting the switch 8 and the intermediate conductor 72, and a step wave is propagated to the intermediate conductor. overshoot occurs. If this oversinet propagates as it is to the Blumlein, similar open neatness will occur in the rectangular wave applied to the load 5, causing the rectangular wave applied to the load 5 to be distorted and its flatness to decrease.

However, in the pulse generator of this embodiment,
Since the inductance at the input part of the Blumlein line is large, the high frequency component of the traveling wave propagating to the intermediate conductor is reduced, and no overshoot is seen in the step wave propagating through the Blumlein line. As a result, as shown in FIG. 2, the flatness of the rectangular wave applied to the end of the load 5 is greatly improved.

In this way, according to this embodiment, by configuring the spiral line so that the number of turns per unit length in the axial direction of the conductor constituting the spiral line increases at the input end connected to the switching element, it is possible to reduce the number of turns applied to the load. The flatness of the rectangular wave generated can be greatly improved.

Note that the present invention is not limited to the embodiments described above, and the spiral conductor installed inside the conductor cylinder may not be double.

Effects of the Invention] As explained above, according to the present invention, the number of turns per unit length in the axial direction of the conductor constituting the spiral line is increased at the input end connected to the switching element, and the number of turns per unit length in the axial direction of the conductor constituting the spiral line is increased at the input end connected to the switching element. I decided to go to the output end. By configuring it so that it is small, the rise at high voltage is fast (
In addition, it is possible to provide a pulse generator that can supply a rectangular wave pulse with a wide pulse width and good flatness.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram showing an embodiment of the pulse generator of the present invention, FIG. 2 is a diagram showing the output waveform of the pulse generator of the present invention, and FIG. 3 is an example of a conventional pulse generator. The circuit diagram, FIG. 4, is a diagram showing an output waveform of a conventional pulse generator. DESCRIPTION OF SYMBOLS 1... Charging power supply, 2... Resistor, 3... Thyratron, 4... Insulator, 5... Load, 6... Blumlein, 71... Conductor cylinder, 72... intermediate conductor, 7
3...Center conductor, 8...Switch. /71 1 yen note '-1'-den 7'''' Figure 1 Time

Claims (1)

[Scope of Claim] A pulse generator that generates a rectangular wave pulse using a multiple spiral line and a switching element arranged in a conductor cylinder, wherein the number of turns per unit length in the axial direction of the conductor constituting the spiral line is A pulse generator characterized in that the pulse generator is large at an input end connected to a switching element and becomes smaller toward an output end connected to a load.