JPS61163536A - Traveling-wave tube - Google Patents

Abstract

PURPOSE:To acquire a collector voltage operating efficiently, by furnishing an efficiency deciding device and a collector voltage deciding device with computers to calculate converting efficiency from the current through the delay circuit and the collector, and from the amplified high frequency power, to a high frequency wave. CONSTITUTION:An interaction of high frequency waves of electron beams from an electron gun of a traveling-wave tube is carried out in the delay circuit 5, and the electron beams are caught by the collector electrode 6. The current through the circuit 5 is detected by the delay circuit current detector 12, the current to the electrode 6 is detected by the collector current detector 13, and the detected current values are added to the efficiency deciding device 14. The amplified high frequency wave output from the output conductor 9 is also added to the efficiency deciding device 14. The device 14 decides the converting efficiency to a high frequency waves, and feeds the result to the voltage deciding device 15. The resultant collector voltage decided by the device 15 is delivered to the voltage control device 16, which controls the collector power source circuit 11, to output a collector voltage which operates most efficiently.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a traveling wave tube that can change the voltage of its collector electrode.

[Conventional technology]

In general, a traveling wave tube is an electron tube that has characteristics such as a wide band and a high amplification degree, and is widely used for amplifying high frequencies. and,
Efforts have been made to improve the conversion efficiency to high-frequency power in order to downsize power supplies and save energy.
This is explained in detail in the prior art section of Japanese Patent No.-86448. In the schematic diagram of the traveling wave tube in Figure 6, the electron gun (1
) is for forming an electron beam, and the cathode (2),
Consists of accelerating electrode (3), Wehnelt electrode If (4),
A slow-wave circuit (5) for interacting the electron beam formed by the electron gun (1) with a high-frequency signal, a first collector (5) for capturing the electron beam that has passed through the slow-wave circuit (Is); 6), a second collector (7), and an input conductor (8) and an output conductor (9) through which high-frequency waves are input and output.

Next, the operation will be explained. The slow wave circuit (5) has a cathode (2
), the electron beam is connected to the slow wave circuit (5) and the cathode (2).
It has a speed due to the potential difference between. Then, due to the interaction with the high frequency, the kinetic energy μ of the electrons in the electron beam is converted into high frequency energy μ, and the amplification of the high frequency proceeds. As a result, although the degree of deceleration of individual electrons forming the electron beam differs, the electron beam as a whole is decelerated. After amplifying the high frequency by interaction with the high frequency,
The electron beams are distributed and collected by the first collector (6) and the second collector (7) according to their respective velocities. Since the velocity of electrons never becomes 0, the potential Vc of the first collector (6) and the potential Vc of the second collector (7)
, can be operated at a potential lower than the potential Va of the slow wave circuit (5). Generally, when a traveling wave tube having multiple collectors is used, a higher potential is applied to the collector closer to the slow wave circuit (5).

As mentioned above, each electron in the electron beam after contributing to high-frequency amplification has a different degree of deceleration, so the velocity is distributed over a wide range, and the faster electrons move to the second collector (7), which has a lower potential. ) and are collected, and the slow electrons are collected by the first collector (6), which has a high potential. That is,
Fast-moving electrons go to the slow wave circuit (5) and the first collector (6)
, and reach the second collector (7) against the decelerating electric field of the second collector (7), but the slow electrons reach the second collector (7).
7) and is collected by the first collector (6).

Therefore, the potential Vc1 of the first collector (6) needs to be raised to a potential that allows even the slowest electrons to reach the first collector (6).

On the other hand, in the case of a traveling wave tube having only one collector, it is necessary to operate the collector at the highest collector potential in the case of having a plurality of collectors.

[Problem that the invention seeks to solve]

Conventional traveling wave tubes are configured as described above, so if there is only one collector, the conversion efficiency to high frequency is low, and if multiple collectors are used to improve conversion efficiency, the configuration becomes complicated. There were some problems, such as: Furthermore, if the operating conditions of the traveling wave tube change, it is impossible to maintain the optimum collector voltage at all times.This invention was made to solve the above problems. The aim is to follow the operating conditions of the traveling wave tube, generate the lowest collector voltage, and obtain a traveling wave tube with high conversion efficiency to high frequency.

[Means for solving problems]

The traveling wave tube according to the present invention includes a high-frequency circuit current detector that detects a current flowing through a high-frequency circuit section, a collector current detector that detects a current flowing through a collector electrode, and a detection signal of these current detectors and a high-frequency an efficiency determining means that takes an output as an input and determines the conversion efficiency to high frequency; a collector voltage determining means that determines a voltage to be applied to the collector electrode based on the output of the efficiency determining means; and a collector voltage determining means that determines a voltage to be applied to the collector electrode based on the output of the collector voltage determining means. and voltage control means for controlling the voltage of the collector electrode.

[Effect]

In this invention, the high frequency output, the detection signal and accelerating voltage from the slow wave circuit current detector, the detection signal from the collector current detector, and the quality of the conversion efficiency from the collector voltage to the high frequency are determined, and according to this determination, the collector voltage control.

[Embodiments of the invention]

FIG. 1 is an overall configuration diagram showing an embodiment of a traveling wave tube according to the present invention. In this embodiment, as is clear from FIG. 1, the electron gun (1) has a negative electrode 41 (2) and an accelerating electrode (3).

It consists of a Uninet electrode (4), a slow wave generator (5) that interacts the generated electron beam with a high-frequency signal, a collector electrode (6) that collects the beam after the interaction, and a human-powered conductor that manually generates the high-frequency signal. (8), an output conductor (9) that outputs an amplified high frequency wave, an accelerating electrode power supply circuit a01 that provides a potential to the accelerating current @ (3) and the slow wave circuit (6), and the collector voltage $1 (6); A collector power supply circuit Q power that provides a potential, a slow wave circuit current detector (2) that detects the current flowing in the slow wave circuit (6), and a collector current detector (2) that detects the current flowing in the collector electrode (6). ), the high frequency power of the traveling wave tube is generated from the slow wave circuit current detector (2), the collector current detector (to), and the high frequency power output from the output conductor (9) (the detector is not shown). Efficiency determining means α for calculating conversion efficiency to electric power and determining its acceptability, collector voltage determining means (to) determining a collector voltage from the output of said efficiency determining means α4, based on said collector voltage determining means (to); The voltage control means Qe controls the voltage of the collector power supply circuit ON.

FIG. 2 is a circuit diagram showing the main electrical connections of the embodiment of FIG. In the diagram, microcomputer sub is CPU (Foundation)
, a memory aS, an input circuit, and an output circuit (2), and an analog multi-preverter (support) to which the detection signals of the slow-wave circuit current detector side and the collector current detector (2) are manually input; An A/D converter (to) converts it into a digital μ, and its output is input to the input circuit (e). In addition, the output circuit (2) is a data latch
, a D/A converter (2) that converts the output to analog;
A collector power supply consisting of a step-up transformer (2) and a smoothing inductor (to) is connected to the voltage control means Q consisting of a comparator, a photocoupler, a resistor w, a 121° thyristor (7), and a gate power supply Ov. This is a configuration for controlling the circuit (b).

Next, the operation of the above embodiment will be explained with reference to FIGS. 8 and 4. FIG. 8 is a flowchart showing the operating program for the traveling wave tube stored in the memory Ql of the microcomputer Q. Figure 4 shows the microcomputer αη
FIG. 2 is an explanatory diagram of a collector voltage generated by a command.

During normal operation, the electron beam emitted from the electron gun (1) passes through the slow wave circuit (5) while passing through the input conductor (
8), and converts the kinetic energy of the electrons in the electron beam into high-frequency energy. That is, the high frequency signal is amplified and output from the output conductor (9). As a result, the degree of deceleration of the electrons forming the electron beam is different and the electron beam as a whole is decelerated because it is not subject to velocity modulation, and the collector electrode (
6) is collected.

Therefore, even if the operating conditions of the traveling wave tube change, the slow wave circuit current a and the collector current IC at that time are detected by the slow wave circuit current detector (2) and the collector current detector (2), and the analog multiplexer ( 2) t - a are alternately input to 4) a converter (to) and converted into a digital signal. Although omitted here, the high frequency output Prf is similarly converted into a digital μ signal. In step -, this information is taken into the input circuit in the microcomputer (incorporated), and the CPU Ql processes the following steps according to the procedure stored in the memo'J DI. In step -, efficiency is calculated using equation (1). (However, the heater power for heating 1 cathode (2) is ignored.) η=Prf/(Va・Ia+Vc4c)
(1) Next, in step -, compare the efficiency η' calculated last time, and if the efficiency η calculated this time is large, in step -, the previous collector voltage vC' and the current collector voltage v
Compare c. VC) V(', then add a predetermined ΔVc to the previous Vc in step Sequence; if VC<vC', subtract a predetermined ΔVc from the previous Vc in step Ill; and in step (B), add VC to the output circuit (2). ).On the other hand,
In step -, when η<η', in step -, the comparison between vc' and VC' is fullZ s Vc>Vc'Narahas? If it is [, V((VC'), step @phantom processing is performed in the same way, and the output is outputted from the output circuit (2) at step 142. Then, in the step circle, the end of the operation is determined and the end is completed. If not, return to step - and repeat the same process, and if it is determined that it is finished, the explanation of the operation by the CPU (to) of the microcomputer aη is completed, and then the subsequent electricity is output from the output circuit (2). The operation of the circuit will be explained.The data latch (2) holds the digital μ data, and the VM converter (2) converts it to analog.Then, this analog value and the step-up transformer (not shown in the figure) are ) is compared with the AC monitor voltage inserted on the next side, and if they are equal, it enters the input of the photocoupler (2) through a comparator that generates a pass μ and a resistor.
A thyristor member is driven through a resistor and a gate power supply, and a desired collector voltage VC is obtained using a step-up transformer and a smoothing inductor. As shown in FIG. 4, this collector voltage can be controlled by the firing timing of the thyristor.

In the above embodiment, when the DC voltage converted into analog by the D/A converter (2) and the AC voltage monitored at the negative side of the step-up transformer (to) are compared, when the absolute values of 1 become equal. An example of using a comparator (to) that generates a pulse to fire the thyristor (7) was shown in Figure 2, but the data latch (
Instead of the D/A converter (a) and comparator, a digital y value corresponding to the firing phase of the thyristor (7) is preset from the output circuit (2) to a presettable counter (not shown). However, it may be configured to count down the pulses of a reference pulse generator (not shown) and generate a pulse for firing the thyristor (1) when the value of the presettable counter reaches zero. Note that in this configuration, the presettable counter must be reset by the zero-cross signal of the step-up transformer (2).

Further, in the above embodiment, the case of a traveling wave tube has been described, but it can be used in any electron beam tube such as a klystron or a gyratron, and the same effects as in the above embodiment can be obtained.

〔Effect of the invention〕

As described above, according to the present invention, efficiency determining means calculates the conversion efficiency to high frequency from the current flowing in the slow wave circuit or the collector, the amplified high frequency power, etc., and obtains the collector voltage that operates most efficiently. Since the collector voltage determining means and the voltage controlling means are provided, the collector generates less heat, so cooling is easy and the source capacity is small.

[Brief explanation of drawings]

Fig. 1 is an overall configuration diagram showing an embodiment of a traveling wave tube according to the present invention, Fig. 2 is a circuit diagram showing its electrical connection, Fig. 8 is a flowchart showing its operation, and Fig. 4 is for explanation of its operation. FIG. 5 is an overall configuration diagram showing a conventional traveling wave tube. In the figure, (1) is an electron gun, (5) is a slow wave circuit, and (6) is an electron gun.
) is the collector electrode, @ is the slow wave circuit current detector, (2) is the collector current detector, α◆ is the efficiency determination means, (II9 is the collector voltage determination means, αQ is the voltage control means, and αη is the microcomputer. Note that the same reference numerals in each figure indicate the same or equivalent parts.

Claims (2)

[Claims] (1) An electron gun that generates an electron beam, a slow-wave circuit section in which high-frequency interaction occurs, a magnetic field focusing device for focusing the electron beam, a collector electrode for collecting the electron beam, and the slow-wave circuit section a slow wave circuit current detector that detects the current flowing through the collector electrode, a collector current detector that detects the current flowing through the collector electrode, and an efficiency determination that determines the conversion efficiency from the detection signals of these current detectors and high frequency output to high frequency. means, collector voltage determining means for determining the voltage applied to the collector electrode based on the output of the efficiency determining means, and voltage control means for controlling the voltage of the collector electrode based on the output of the collector voltage determining means. A traveling wave tube characterized by: (2) The traveling wave tube according to claim 1, wherein the efficiency determining means and the collector voltage determining means are realized by a microcomputer.