JPH03192918A - Pulse generator - Google Patents

Abstract

PURPOSE:To supply a high voltage rectangular wave pulse fast in rising with wide pulse width efficiently to a high impedance load by forming a bloom line of a multiple spiral winding arranged in a conductor cylinder, and employing a wide conductor as the conductor forming the multiple spiral winding. CONSTITUTION:A center conductor 10 and an intermediate conductor 11 forming a bloom line are formed in spiral and arranged in a conductor cylinder 12 to form a multiple spiral line 13. The width (w) of the center conductor 10 and the intermediate conductor 11 formed in spiral is formed sufficiently wider than the interval (g) of spiral turns, then a static capacitance C1 between the conductor cylinder 12 and the center conductor 10 becomes smaller and the thickness (d) between the center conductor 10 and the intermediate conductor 11 is formed sufficiently thin, then the static capacitance C2 at a high frequency band between the spiral turns is decreased. Thus, a rectangular wave pulse with a high voltage, fast rising and wide pulse width is supplied efficiently to a high impedance load.

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 pulses, a rectangular wave pulse generator that combines a capacitance element, an inductance element, and a thyratron has often been used. FIG. 7 shows an example of such a rectangular wave pulse generator. That is, the pulse forming line 2 is charged to a constant voltage by the charging power source 1, and then the thyratron 3 is turned on to generate a rectangular wave pulse in the load 5. The withstand voltage of this thyratron is normally several tens of kilovolts, and if a voltage higher than that is to be generated, a pulse transformer 4 is used to boost the voltage as shown in the figure.

Furthermore, when such a pulse forming line is used, the impedance of the line must be equal to the impedance of the load, and the output voltage will be 1/2 of the charging voltage on the primary side of the pulse transformer.

By the way, as a method for increasing the output voltage, in addition to using the above-mentioned pulse transformer, there is a method of serializing pulse forming circuits such as Blumlein type and stack line type. FIG. 8 shows a rectangular wave pulse generator using a Blumlein 6, and 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 5 is set to R/2-Z, -22, a rectangular wave pulse with a voltage equal to the charging voltage can be obtained at the output.

(Problem to be Solved by the Invention) Incidentally, 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 pulse voltage and shorten the rise and fall. Furthermore, if it is desired to further increase the output voltage, there is a limit to simply connecting the pulse forming lines in series, and a pulse transformer must be used. However, the method using a pulse transformer has the following problems. In other words, when applying a fast-rising pulse to a high-impedance load such as a klystron, the impedance of the stray capacitance of the pulse transformer cannot be ignored relative to the load impedance, and the impedance applied to the primary side of the transformer becomes It becomes extremely difficult to generate the waveform as it is on the secondary side.

Furthermore, when a Blumlein type pulse forming line is used to increase the pulse voltage and shorten the rise time without using a pulse transformer, 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 length of several tens of meters is required. A line will be 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, making practical installation extremely difficult.

The present invention was proposed to solve the above-mentioned problems, and its purpose is to efficiently supply a high-voltage, fast-rise, and wide-width rectangular wave pulse to a high impedance load. The object of the present invention is to provide a small-sized pulse generator that can perform the following functions.

[Structure of the Invention] (Means for Solving the Problem) The invention according to claim 1 provides a pulse generator that generates a rectangular wave pulse using a Blumlein and a switching element, in which the Blumlein is placed inside a conductive cylinder. The present invention is characterized in that it is composed of arranged multiple spiral windings, and that a wide conductor is used as a conductor constituting the multiple spiral windings.

Further, in the invention according to claim 2, the Blumlein is constituted by multiple spiral windings disposed within a conductor cylinder, and the winding pitch of the conductor constituting the multiple spiral windings becomes narrower at the end of the conductor cylinder. It is characterized by being configured as follows.

Furthermore, the invention according to claim 3 provides a Blumlein comprising multiple spiral windings disposed within a conductor cylinder, and a conductor disposed at the input and output ends of the Blumlein at an arbitrary angle with respect to the central axis of the conductor cylinder. This is characterized in that the conductor is drawn out from the conductor cylinder.

(Function) In the pulse generator according to the invention according to claim 1,
By configuring the conductor constituting the Blumlein in a cylindrical shape, the inductance tank per unit length in the direction of the central axis of the conductor cylinder increases, and the surge impedance of the Blumlein line increases. Furthermore, since the total line length along the spiral can be increased without increasing the length of the conductor cylinder, the pulse width determined by the round trip time of the total line length can be increased. Also, at this time, by using a wide and thin conductor as the conductor constituting the multiple spiral line, the leakage capacitance of the spiral conductor is reduced, and the line approaches the ideal Blumlein.

Further, according to the invention according to claim 2. (In the pulse generator, the winding pitch is changed between the ends and the middle part to reduce the end effect of the line, so the flat characteristics of the output waveform are improved.

Furthermore, in the l<lus generator according to the third aspect of the present invention, since the mounting angle of the conductor at the input/output end of the line can be changed arbitrarily, the arrangement of the entire apparatus can be made compact.

(Example) Hereinafter, an example of the present invention will be specifically described with reference to FIGS. 1 to 4. Incidentally, the same members as those of the conventional type shown in FIGS. 7 and 8 are given the same reference numerals, and the description thereof will be omitted.

In this embodiment, as shown in FIG. 1, the center conductor 10 and intermediate conductor 11 constituting the Blumlein are configured in a spiral shape and disposed within a conductor cylinder 12, forming a multiple spiral line 13. has been done. Note that the total lengths of the center conductor 10 and the intermediate conductor 11 along the spiral are substantially equal to each other. Further, the width W of the central conductor 10 and the intermediate conductor 110, which are configured in a spiral shape, is set to be wider by −1− than the interval g between the turns of the spiral, as shown in FIG. Therefore, as shown in FIG. 3, the capacitance C2 between the conductor cylinder 12 and the center conductor 10 is small.

Furthermore, since the thickness d of the center conductor 10 and the intermediate conductor 11 is configured to be sufficiently thin, the capacitance C2 in the high frequency region between the turns of the spiral is also small. Furthermore, as shown in FIG. 2, the widths of the central conductor 10 and the intermediate conductor 11, which are configured in a spiral shape, are configured to become narrower toward the ends at the ends A and 8 of the line, respectively. ing. In this case, the interval g between turns of the spiral is not narrow, and the winding pitch increases toward the ends. Further, the conductor at the input end 14 and output end 15 portion of the multiple spiral line 13 is connected to the conductor cylinder 1.
It is connected to the central axis 16 of No. 2 at a predetermined angle.

Further, the input terminal 14 is connected to the charging power source 1 of the line,
Output end 15 is connected to load 5. Further, a short circuit switch 17 is provided between the intermediate conductor 11 and the conductor cylinder 12.
is provided.

The pulse generator of this embodiment having such a configuration operates as described below. That is, the intermediate conductor 11 charged by the charging power source 1 is grounded by closing the switch 17. Then, a step wave having a rise time determined by the characteristics of the switch propagates through the distributed constant line composed of the conductor circle n12 and the intermediate conductor 11. At this time, since the capacitance C1 between the center conductor 10 and the conductor cylinder 12 is small, no voltage is generated in the distributed constant line composed of the center conductor 10 and the intermediate conductor 11. Furthermore, since the capacitance C2 between the turns of the spiral is also small, the step wave propagates along the spiral. When this step wave reaches the output end 15, a step voltage is applied to the load 5. Furthermore, this step wave is split into a distributed constant line made up of the center conductor 10 and the intermediate conductor 11 at the output end 15, and a distributed constant line made up of the intermediate conductor 11 and the conductor cylinder 12, and then again at the input end. It propagates to 14. Then, it is reflected once again at the input end 14 and reaches the output end 15. At this time, the voltage applied to the load 5 changes to OV. As a result, the voltage waveform applied to the load 5 becomes a rectangular wave having a pulse width equal to the round trip time along the spiral of the center conductor 10 and the intermediate conductor 11.

Incidentally, the flatness of the flat portion of the rectangular wave is generally distorted due to the effect of the end portion of the Blumlein line. That is, it is known that the spread of magnetic flux at the end of the line changes the characteristics of the distributed constant line, causing unevenness in the flat part of the output rectangular wave. However, in this example,
Center conductor 10 and intermediate conductor 1 configured in a spiral shape
By increasing the winding pitch of 1 at the ends of the line, it is possible to suppress the spread of magnetic flux at the ends. As a result, it is possible to reduce the influence of changes in the characteristics of the distributed constant line on the output waveform, and it is possible to obtain a flat rectangular wave with a flat portion.

In addition, in order to charge the Blumlein line or take out the output, it is necessary to connect it to external equipment via a conductor, but in this embodiment, the input/output conductor is located at the center of the conductor cylinder 12. Since it is arranged at a predetermined angle with respect to the axis 16, the conductor cylinder 12 can be arranged vertically.

As a result, space can be used effectively, and the entire device including the charging power source and the load device can be made compact.

In this way, according to this embodiment, the Blumlein line is configured using a spiral conductor, so when generating a rectangular wave with a wide pulse width, the pipe length is significantly shorter than that of the conventional one. Square wave pulses can be generated on the line. Further, by using a wide and thin conductor as the conductor constituting the multiple spiral line, the output waveform can be approximated to a precise rectangular wave. Furthermore, by changing the winding pitch of the spiral at the end of the line, it is possible to reduce distortion of the waveform due to the end effect of the line. In addition, since the input/output conductors can be attached to the multiple spiral line at a predetermined angle to the central axis of the spiral line, the device can be placed vertically.
The entire device can be made compact.

Note that the present invention is not limited to the embodiments described above, and as shown in FIG. It's okay. For example, in FIG. 5, the winding radius r2o at the end of the intermediate conductor 20 is the same as the winding radius r2o at the middle part.
It is configured narrower than 1. With this configuration, it is possible to correct the distortion in the characteristics of the distributed constant line due to the spread of magnetic flux at the end of the line, and it is possible to reduce distortion in the output waveform.

Further, as shown in FIG. 6, the multiple spiral line and the charging power source 1 may be housed in the same container 22. in this case,
The entire device becomes even more compact and space can be used more effectively.

[Effects of the Invention] As explained above, according to the present invention, the Blumlein is constructed from multiple spiral windings arranged within a conductor cylinder, and a wide conductor is used as the conductor constituting the multiple spiral windings. or by configuring the winding pitch of the conductor constituting the multiple spiral winding to be narrower at the end of the conductor cylinder, or by configuring the winding pitch of the conductor constituting the multiple spiral winding to become narrower at the end of the conductor cylinder, or by By configuring the conductor to be drawn out of the conductor cylinder at an arbitrary angle with respect to the center axis of the conductor cylinder, it is possible to efficiently supply a high voltage, fast rise, and wide pulse width rectangular wave pulse to a high impedance load. It is possible to provide a small-sized pulse generator that can perform the following functions.

[Brief explanation of drawings]

FIG. 1 is a schematic circuit diagram showing one embodiment of the pulse generator of the present invention, FIG. 2 is an exploded perspective view showing the main parts of FIG. 1, and FIG.
The figure is a perspective view showing the main part of FIG. 1, FIG. 4 is an enlarged perspective view showing the conductor part of FIG. 1, FIGS. 5 and 6 are schematic circuit diagrams showing other embodiments of the present invention, 7 and 8 are schematic circuit diagrams showing an example of a conventional pulse generator. 1... Charging power supply, 2... Pulse forming line, 3...
Thyratron, 4... Pulse transformer, 5... Load, 6... Blumlein, 10... Center conductor, 11
... intermediate conductor, 12 ... conductor cylinder, 13 ... multiple spiral line, 14 ... input end, 15 ... output end, 16 ... center axis, 17 ... switch, 20 ...・・・
Intermediate conductor, 21... Conductor cylinder, 22... Container. Fig. Fig. Fig. Fig. Fig. Fig. Fig. Fig. Fig. Fig.

Claims (3)

[Claims] (1) In a pulse generator that generates a rectangular wave pulse using a Blumlein and a switching element, the Blumlein is composed of multiple spiral windings arranged in a conductor cylinder, and the conductor constituting the multiple spiral windings A pulse generator characterized by using a wide conductor. (2) In a pulse generator that generates a rectangular wave pulse using a Blumlein and a switching element, the Blumlein is composed of multiple spiral windings arranged in a conductor cylinder, and the conductor constituting the multiple spiral windings 1. A pulse generator characterized in that the winding pitch of the conductor is narrower at an end of the conductor cylinder. (3) In a pulse generator that generates a rectangular wave pulse using a Blumlein and a switching element, the Blumlein is composed of multiple spiral windings arranged inside a conductive cylinder, and the Blumlein is arranged at the input and output ends of the multi-spiral winding. A pulse generator characterized in that a conductor is drawn out of the conductor cylinder at an arbitrary angle with respect to the central axis of the conductor cylinder.