JPH0638365Y2 - Spiral voltage output circuit of traveling wave tube amplifier - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention relates to a spiral voltage output circuit having a monitoring voltage output circuit of a spiral current of a traveling wave tube among power supplies of a traveling wave tube amplifier, and particularly to erroneous monitoring. The present invention relates to a spiral voltage output circuit for a traveling-wave tube amplifier that does not output a voltage.

[Prior Art] Conventionally, a traveling-wave tube amplifier composed of a spiral traveling-wave tube and a power supply for supplying a voltage to the spiral traveling-wave tube has been known as an amplifier for high-gain microwaves. It is common practice in spiral tube amplifiers to monitor the spiral current. By monitoring the spiral current, it is possible to estimate the operating state and degree of deterioration of the traveling-wave tube. From the monitor information, you can adjust the operating conditions such as the input level voltage and determine when to replace the traveling-wave tube. You can judge. Therefore, it is important that the monitor output accurately represents the spiral current.

FIG. 5 shows a conventional example of a spiral voltage output circuit with a spiral current monitoring output circuit of a traveling-wave tube amplifier circuit, which constitutes a power supply whose size and weight are reduced and the circuit is simplified as much as possible. Reference numeral 1 is a traveling wave tube, and 2 is a spiral voltage output circuit.
The traveling wave tube 1 is composed of a spiral electrode 11 and a cathode 12, and a spiral voltage is applied from a spiral voltage output circuit 2. The spiral voltage output circuit 2 includes a high voltage generator 21 for generating a high voltage, a spiral voltage control circuit 22 for generating a control voltage, a bipolar transistor 23 for a high voltage regulator for generating a spiral voltage with the control voltage being a constant value, and a spiral. It consists of a current monitoring output terminal 24, resistors R ₁ , R ₂ , ..., R ₆ .

In the steady state of the above conventional example, when a part of the electron beam emitted from the cathode 12 of the traveling wave tube 1 hits the spiral electrode 11, it becomes a spiral current, and the cathode 12, the high voltage generation circuit 21, and the resistance.
A current flows in a loop circuit that connects R ₃ , the bipolar transistor 23 for high-voltage regulator, the resistor R ₅ , and the spiral electrode 11.
As a result, a voltage proportional to the spiral current is generated across the resistor R ₅ , and this voltage is taken out from the spiral current monitor output terminal through the resistor R ₆ and becomes the spiral current monitor output.

In order to operate the traveling wave tube, it is necessary to first turn on the heater of the cathode 12 and allow a sufficient time for the cathode temperature to reach a normal value, and then apply a high voltage. In the simplified conventional power supply, a low voltage for operating the spiral voltage control circuit 22 and the like is applied at the same time as the heater power supply is operated.

[Problems to be Solved by the Invention] However, in the spiral voltage output circuit in the above-mentioned conventional technique, an erroneous spiral current is generated during the cathode preheating period until the cathode heater is turned on and the cathode temperature reaches a normal value. Monitoring voltage is output, and preventing it is a problem to be solved. That is, in the conventional spiral voltage output circuit 2, the high voltage is detected in the spiral voltage control circuit 22 and a high voltage is generated because a general voltage stabilization control loop is formed so that this voltage becomes constant. In the state in which only the low voltage that operates the spiral voltage control circuit is not applied and the high voltage that is detected is sufficiently low, the control loop closes the high voltage regulator bipolar transistor 23 so that the output becomes high. The control voltage for driving up to is output from the spiral voltage control circuit 22. As a result, the resistance R _4, the base-emitter forward junction of the high-pressure regulator bipolar transistor 23, the number times larger current flows than in the steady state through the resistor R _5, the voltage drop across the resistor R ₅ Occurs, and a false voltage (false signal) that appears as if a spiral current is flowing is generated at the spiral current monitoring output terminal 24 even though no spiral current is flowing. In the steady state where a high voltage is applied, the bipolar transistor
Since the current flowing from the base of the bipolar transistor 23 is much smaller than the current corresponding to the spiral current flowing in 23, the influence on the monitor information can be ignored and no problem occurs.

Even if the above false false signal occurs, if you can retrieve a lot of monitor information with the traveling wave tube amplifier at hand,
Since the operating state of traveling wave tube 1 can be grasped by other information, there is no serious problem. However, when the traveling wave tube amplifier is installed in a remote place and the information to monitor it is limited,
There is the inconvenience that the operating state of the traveling wave tube may be erroneously determined.

The present invention was devised to solve the above-mentioned problems, and in a traveling-wave tube amplifier in which the circuit is simplified for downsizing and weight reduction, cathode preheating before applying a high voltage to the traveling-wave tube. An object of the present invention is to provide a spiral voltage output circuit of a traveling wave tube amplifier that prevents an unnecessary spurious signal from being generated at a spiral current monitoring output terminal during a period.

[Means for Solving the Problems] The configuration of the spiral voltage output circuit of the traveling-wave tube amplifier of the present invention for achieving the above object is a high voltage generating circuit for generating a high voltage and a constant high voltage output thereof. A control circuit that creates a control voltage to maintain the value,
A transistor proportional to the spiral current of the traveling-wave tube that is connected to this transistor and outputs a spiral voltage that is applied to the traveling-wave tube with this high-voltage output as a constant value when this control voltage is input. In a spiral voltage output circuit of a traveling-wave tube amplifier having a resistance that causes a drop, a control voltage input of the transistor and the resistance are applied during a period in which a regular voltage is not applied except for a heater electrode that heats the cathode of the traveling-wave tube. It is characterized in that a switch means for invalidating one or both of the voltage drop outputs of 1 is added, or a MOS FET is used for the transistor.

[Operation] The first means of the present invention is to input to the transistor that outputs a spiral voltage by the switch means that operates in synchronization with the preheating period (the period when the voltage is applied only to the heater electrode) of the cathode of the traveling wave tube. The control voltage to be applied is disabled to disable the monitor output generated in the resistor for monitoring the spiral current, or the monitor output is directly disabled to prevent the generation of the false signal during the above period.

In addition, the second means of the present invention uses a MOS FET as a transistor for outputting a spiral voltage, so that the insulation voltage between the gate and the source is used to control the current by a control voltage applied to the gate. The current is prevented from flowing through the resistor to prevent the generation of the false signal.

[Embodiment] An embodiment of the present invention will be described below in detail with reference to the drawings.

FIG. 1 is a circuit configuration diagram showing a first embodiment of the present invention. In this embodiment, a switch means is added to the resistor R5 for detecting the spiral current monitoring output in the conventional example shown in FIG. ₅ , and the output is invalidated during the preheating period of the heater of the traveling wave tube. In the present embodiment, the same members as those in the conventional example will be described with the same reference numerals as those in the conventional example. The traveling wave tube amplifier includes a traveling wave tube 1 and a spiral voltage output circuit 2.
The traveling wave tube 1 is composed of a spiral electrode 11 and a cathode 12, and a spiral voltage is applied from a spiral voltage output circuit 2. The spiral voltage output circuit 2 is a high voltage generation circuit 21 for generating a high voltage, and a control for detecting the high voltage output with resistors R ₁ and R ₂ and comparing it with a reference voltage to make the high voltage a constant value. A spiral voltage control circuit 22 that creates a voltage and the high voltage output that is supplied to the collector via a resistor R ₃ are controlled to a constant value by the control voltage input to the base via a resistor R ₄ to create a spiral voltage. The high-voltage regulator bipolar transistor 23, a resistor R ₅ that is connected between the emitter of the transistor 23 and the ground potential, and applies the above-mentioned helical voltage to the helical electrode 11 of the traveling wave tube 1, and a helix appearing in this resistor R _5. It is composed of a spiral current monitoring output terminal 24 and the like which outputs a voltage drop proportional to the current via a resistor R ₆ .

Or until a conventional example the same configuration, in the first embodiment adds transistor 25 to disable the short-circuit the voltage drop across the resistor R _5. A monitor output control input terminal 26 is provided at the base of the transistor 25 via a resistor R ₇ . To this input terminal 26, for example, a positive voltage generated in the cathode preheating period created by a timer or the like in the spiral voltage control circuit 22 is generated and applied, and the transistor 25 is made conductive by the base-emitter current flowing thereby.

With the above configuration, in the first embodiment, a positive voltage is applied from the control circuit 22 or the like to the monitor output control input terminal 26 during the cathode preheating period to saturate the transistor 25 and short-circuit both ends of the resistor R ₅ . This prevents an incorrect output voltage from appearing at the spiral current monitoring output terminal 24 during the cathode preheat period. When transitioning to normal operation (steady state) after the cathode preheating period, the transistor 25 is turned off by setting the voltage applied to the monitor output control input terminal 26 to 0V in synchronization with the control signal for turning on the high voltage, thereby turning off the resistor R. Release the short-circuit condition of ₅ . Therefore, a voltage drop occurs in the resistor R ₅ in proportion to the spiral current of the traveling wave tube 1, and the spiral current monitoring output can be taken out from the spiral current monitoring output terminal 24.

FIG. 2 is a circuit configuration diagram showing a second embodiment of the present invention. This embodiment has almost the same configuration as that of the first embodiment except that a transistor 25, a resistor R ₇ , a monitor output control input terminal 26
A switch means consisting of is added between the spiral current monitoring output terminal 24 and the ground potential, and the monitoring output which is erroneously output through the resistor R ₆ due to the voltage drop generated in the resistor R ₅ during the cathode preheating period is invalidated by the short circuit. To do. The operation of the transistor 25 is the same as that of the first embodiment, and during the cathode preheating period, the conduction of the transistor 25 keeps the spiral current monitoring output terminal 24 at the ground potential and prevents the output of the false signal, and the normal operation. Sometimes it is turned off so that the spiral current monitoring output can be taken out.

FIG. 3 is a circuit configuration diagram showing a third embodiment of the present invention. In this embodiment, the control voltage input to the base of the bipolar transistor 23 for a high voltage regulator of the conventional example shown in FIG. 5 is invalidated by a switch means including a transistor 27 and the bipolar transistor 23 is turned off, thereby making a cathode. The current is prevented from flowing through the resistor R ₅ during the preheating period to prevent generation of false monitoring output. Third
In the figure, the same members as those in the conventional example are designated by the same reference numerals,
The description thereof has been given in the first embodiment, and will be omitted. In the third embodiment, the transistor 27 is connected between the base of the high voltage regulator bipolar transistor 23 and the ground potential. The base of this transistor 27 has a resistor R ₈
A high-voltage output control input terminal 28 is provided via. A positive voltage is generated and applied to the input terminal 28 during a cathode preheating period created by a timer or the like in the control circuit 22, and the base-emitter current flowing thereby causes the transistor 27 to conduct.

With the above configuration, in the third embodiment, a positive voltage is applied from the spiral voltage control circuit 22 or the like to the high voltage output control input terminal 28 during the cathode preheating period to saturate the transistor 27 and set the base potential of the high voltage transistor 23. Keep it at ground potential and invalidate the control voltage input via resistor R ₄ . As a result, the high-voltage regulator bipolar transistor 23 is turned off, no current flows through the resistor R _5, and no monitoring output appears at the spiral current monitoring output terminal 24. When transitioning to normal operation after the cathode preheating period, the voltage applied to the high-voltage output control input terminal 28 should be 0 V in synchronization with the control signal for turning on the high-voltage.
By this, the transistor 27 is turned off, and the control voltage can be input from the spiral voltage output circuit 22 to the high-voltage regulator bipolar transistor 23. Therefore, a voltage drop occurs in the resistor R ₅ in proportion to the spiral current of the traveling wave tube 1, and the spiral current monitoring output can be taken out from the spiral current monitoring output terminal 24.

FIG. 4 is a circuit configuration diagram showing a fourth embodiment of the present invention. In this embodiment, a MOS FET (M
OS type field effect transistor) 29 is used.
Therefore, since the circuit configuration shown in FIG. 4 is almost the same as the conventional one, the same reference numerals are given to the equivalent members and the description thereof will be omitted.

In the steady state of the spiral voltage output circuit 1 having the above configuration,
The output voltage from the high voltage generation circuit 21 is divided by a voltage divider composed of resistors R ₁ and R ₂ and applied to the spiral voltage control circuit 22, where it is compared with the reference voltage and becomes a high voltage regulator MOS FET29. Generate a control voltage for controlling. In the traveling wave tube 1, when a part of the electron beam emitted / formed from the cathode 12 collides with the spiral electrode 11, the cathode 12, the high-voltage generating circuit 21, the resistor R ₃ , the MOS FET 29, the resistor R ₅ , the spiral electrode 11 A current (helical current) flows in the loop circuit connecting the two. As a result, a voltage proportional to the spiral current is generated across the resistor R ₅ , and the spiral current monitoring voltage is taken out from the spiral current monitoring output terminal 24 through the resistor R ₆ . On the other hand, during the cathode preheating period, a positive voltage is applied from the spiral voltage control circuit 22 to the gate of the MOS FET 29 as in the steady state.
FET 29 gate, between a source (resistor R _4, electrodes connected to R ₅ are each MOS FET 29 gate, source) because no current flows have been insulated, the voltage drop across the resistor R ₅ is not generated Therefore, there is no output from the spiral voltage monitoring output terminal 24, and the output of an incorrect monitoring voltage is prevented.

If the first or second embodiment is carried out together with the third embodiment, the reliability is further increased. As described above, the present invention is not limited to the above-described embodiments, and it is needless to say that the present invention can be variously applied and various embodiments can be taken in accordance with the gist thereof.

[Effect of Device] As is clear from the above description, the spiral voltage output circuit of the traveling wave tube amplifier of the present invention has the following effects.

(1) It is possible to prevent a false signal from appearing at the spiral current monitoring output terminal during the cathode preheating period of the traveling wave tube.

(2) Since the appearance of a false signal can be prevented, the operating state of the traveling wave tube can be accurately grasped from a remote point by monitoring only the spiral current.

(3) Also, without using the present invention, it is possible to avoid the complicated circuit configuration of the power supply, the increase in the weight of the power supply, and the increase in the size of the power supply, which are required to prevent the appearance of the false signal in the spiral current monitoring output. .

[Brief description of drawings]

FIG. 1 is a circuit configuration diagram showing a first embodiment of the present invention, and FIG.
FIG. 4 is a circuit configuration diagram showing a second embodiment of the present invention, FIG. 3 is a circuit configuration diagram showing a third embodiment of the present invention, and FIG. 4 is a circuit configuration showing a fourth embodiment of the present invention. FIG. 5 and FIG. 5 are circuit configuration diagrams of a conventional spiral voltage output circuit. 1 ... Traveling wave tube, 2 ... Helical voltage output circuit, 11 ... Cathode, 21 ... High voltage generator, 22 ... Helical voltage control circuit, 23 ... High voltage regulator bipolar transistor, 24 ... Helical current monitoring an output terminal, 25, 27 ...... transistor (switching means), 29 ...... MOS FET, R 5 ...... resistance.

Claims (2)

[Scope of utility model registration request] 1. A high voltage generating circuit for generating a high voltage,
A control circuit for generating a control voltage for maintaining the high voltage output at a constant value, a transistor for receiving the control voltage and outputting a spiral voltage to be applied to the traveling wave tube with the high voltage output as a constant value, and a transistor for this transistor. A spiral voltage output circuit of a traveling-wave tube amplifier having a resistor that generates a voltage drop proportional to the spiral current of the traveling-wave tube that is connected and flows by applying the spiral voltage, except for a heater electrode that heats the cathode of the traveling-wave tube. The spiral voltage of the traveling-wave tube amplifier is characterized by adding switch means for invalidating one or both of the control voltage input of the transistor and the voltage drop output of the resistor during the period when the regular voltage is not applied. Output circuit. 2. A high voltage generating circuit for generating a high voltage,
A control circuit for generating a control voltage for maintaining the high voltage output at a constant value, a transistor for receiving the control voltage and outputting a spiral voltage to be applied to the traveling wave tube with the high voltage output as a constant value, and a transistor for this transistor. A spiral voltage output circuit of a traveling-wave tube amplifier having a resistor that generates a voltage drop proportional to a spiral current of the traveling-wave tube that is connected and flows by applying the spiral voltage, characterized in that a MOS FET is used for the transistor. Voltage output circuit of traveling wave tube amplifier.