JP2012216461A - High-frequency circuit system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a high-frequency circuit system capable of suppressing phase fluctuation even when a phase of a high-frequency signal fluctuates at a high speed by load fluctuation of an electron tube such as a traveling-wave tube and the like.SOLUTION: A high-frequency circuit system having an electron tube and a power supply device supplying a predetermined DC voltage to the electron tube, has a phase comparator outputting a voltage corresponding to a phase difference between a first high-frequency signal to be inputted to the electron tube and a second high-frequency signal outputted from the electron tube. Based on an output voltage from the phase comparator, in the case that there is a phase change in the second high-frequency signal to the first high-frequency signal, the power supply device controls the DC voltage to be supplied to between a cathode electrode and a helix so that the phase of the first high-frequency signal and the phase of the second high-frequency signal are accorded with each other.

Description

  The present invention relates to an electron tube used for amplification and oscillation of a high-frequency signal and a high-frequency circuit system including a power supply device that supplies a predetermined DC voltage to each electrode of the electron tube.

  A traveling wave tube is an electron tube used for amplifying or oscillating a high frequency (microwave) signal by the interaction between an electron beam emitted from an electron gun and a high frequency circuit. The traveling wave tube 1 is, for example, as shown in FIG. 5, an electron gun 10 that emits an electron beam 50, and a high-frequency circuit that interacts a high-frequency (microwave) signal with the electron beam 50 emitted from the electron gun 10. A certain helix 20, a collector electrode 30 that captures the electron beam 50 output from the helix 20, and an anode that extracts electrons from the electron gun 10 and guides the electron beam 50 emitted from the electron gun 10 into the spiral helix 20. This is a configuration having an electrode 40. The electron gun 10 includes, for example, a cathode electrode 11 that emits thermoelectrons, a heater 12 that gives thermal energy to the cathode electrode 11 to emit thermoelectrons, and an electron beam 50 that focuses the electrons emitted from the cathode electrode 11. And Wehnelt electrode 13 for forming the.

  The electron beam 50 emitted from the electron gun 10 is accelerated by the potential difference between the cathode electrode 11 and the helix 20, introduced into the helix 20, and interacts with a high-frequency signal input from one end of the helix 20. Progress inside. The electron beam 50 that has passed through the inside of the helix 20 is captured by the collector electrode 30. At this time, a high frequency signal amplified by the interaction with the electron beam 50 is output from the other end of the helix 20.

  The power supply device 60 has a helix power supply 61 that supplies a negative DC voltage (helix voltage Ehel) with respect to the cathode electrode 11 based on the potential (HELIX) of the helix 20, and a potential (H / K) of the cathode electrode 11 as a reference. A collector power supply 62 that supplies a positive DC voltage (collector voltage Ecol) to the collector electrode 30 and a positive DC voltage (anode voltage Ea) to the anode electrode 40 with reference to the potential of the cathode electrode 11. The anode power supply 63 and a heater power supply 64 that supplies a heater voltage Eheat that is an AC voltage or a DC voltage to the heater 12 of the electron gun 10 with reference to the potential of the cathode electrode 11. The helix 20 is usually connected to the case of the traveling wave tube 1 and grounded.

  FIG. 5 shows a configuration example of the traveling wave tube 1 including one collector electrode 30, but the traveling wave tube 1 may include a plurality of collector electrodes 30. 5 shows a configuration example in which the anode voltage Ea is supplied to the anode electrode 40, but there is a configuration in which the anode electrode 40 is grounded by being connected to the helix 20.

  The helix voltage Ehel, the collector voltage Ecol, the anode voltage Ea, and the heater voltage Eheat are, for example, a transformer, a rectifier circuit that converts an AC voltage supplied from a commercial power source or the like into a DC voltage, and a DC voltage supplied from the rectifier circuit. Is generated using an inverter connected to the primary winding of the transformer, and a rectifier circuit that converts the AC voltage output from the secondary winding of the transformer into a DC voltage. . Usually, the helix voltage Ehel is set to a DC high voltage of about several hundred to several kV, and the collector voltage Ecol is set to a DC high voltage lower than the helix voltage Ehel. The anode voltage Ea is set within the range of 0V (potential of the cathode electrode 11) to the helix voltage Ehel, and the heater voltage Eheat is set to about several volts to several tens of volts.

  Incidentally, it is known that in the traveling wave tube 1, when the helix voltage Ehel varies, the phase of the high-frequency signal output from the traveling wave tube 1 also varies (see, for example, Patent Document 1). The fluctuation of the helix voltage Ehel occurs when the load due to the traveling wave tube 1 suddenly varies, such as when a high frequency signal is output from the traveling wave tube 1 in a burst form. In order to output a high frequency signal from the traveling wave tube 1 in a burst shape, a voltage may be applied to the anode electrode 40 in a pulse shape or a step shape.

  In recent wireless communication apparatuses, various phase shift keying (PSK) systems are employed in order to improve information transmission efficiency. When traveling wave tube 1 is used to amplify a radio frequency (RF) signal transmitted by such a wireless communication device, phase fluctuations in traveling wave tube 1 cause erroneous transmission of information.

  Therefore, in the power supply device 60 for the traveling wave tube 1 as shown in FIG. 5, it is desirable to suppress the fluctuation of the helix voltage Ehel due to the fluctuation of the load caused by the traveling wave tube 1.

  In order to suppress the fluctuation of the helix voltage Ehel, for example, as shown in FIG. 6, the total capacity of the helix power supply 61 is increased by increasing the number of rectifying capacitors C connected in parallel to the cathode electrode 11 and the helix 20. It is possible to consider a configuration that increases

  However, in such a configuration that increases the total capacity of the rectifying capacitor C, there is a problem that the number of components of the power supply device 60 increases. In general, the rectifying capacitor C having a relatively large capacity and a high withstand voltage has a large package size. Therefore, when the number of rectifying capacitors C increases, the power supply device 60 becomes large.

  Further, as another configuration for suppressing the fluctuation of the helix voltage Ehel, for example, as shown in FIG. 7, the helix voltage Ehel is divided using a resistor R or the like, and the divided helix voltage Ehel is converted into the primary of the transformer 200. A configuration in which the helix voltage Ehel output from the rectifier circuit 230 connected to the secondary winding of the transformer 200 is stabilized by feedback (negative feedback) to the inverter 220 connected to the winding is conceivable.

  However, in such a configuration, since the delay amount by the inverter 220, the transformer 200, the rectifier circuit 230, and the like provided in the feedback loop is large, it is difficult to follow when the helix voltage Ehel fluctuates at high speed. Therefore, when the helix voltage Ehel fluctuates at a high speed due to a sudden change in the load of the traveling wave tube 1, the configuration shown in FIG. 7 cannot suppress the fluctuation of the helix voltage Ehel.

  In Patent Document 1, a traveling wave tube is detected by detecting the phase of a high frequency signal output from the traveling wave tube and adjusting the phase of the high frequency signal input to the traveling wave tube based on the detected phase. Describes a technique for correcting the phase fluctuation of a high-frequency signal.

  Patent Document 2 discloses a transistor (charging bypass) that bypasses a series regulator connected to the output side of a rectifier circuit connected to a secondary winding of a transformer when a high-frequency signal is output from a traveling wave tube in a burst shape. The circuit is turned on and the charge is supplied from the rectifier circuit to the rectifier capacitor at a high speed to reduce the time required for the helix voltage Ehel, which has dropped due to load fluctuations, to stabilize at the original voltage. Yes.

Japanese Patent Laid-Open No. 6-61761 JP 2007-323915 A

  As described above, in the configuration in which the total capacity is increased by increasing the number of rectifying capacitors shown in FIG. 6, there is a problem that the power supply device becomes large. Further, in the configuration in which the negative feedback circuit shown in FIG. 7 is provided, it is difficult to follow when the helix voltage fluctuates at high speed.

  The technique described in Patent Document 2 can stabilize the helix voltage at high speed when supplying a pulse signal to the anode electrode, that is, when outputting a high-frequency signal from the traveling wave tube in a burst shape. However, since the power supply device described in Patent Document 2 is configured to control the charging bypass circuit in synchronization with a pulse signal supplied to the anode electrode, the load due to the traveling wave tube is suddenly increased for other reasons. When the helix voltage fluctuates and the phase changes, it cannot be dealt with.

  The present invention has been made to solve the problems of the background art as described above, and even when the phase of a high-frequency signal changes at a high speed due to a load fluctuation of an electron tube such as a traveling wave tube, the phase change is performed. An object is to provide a high-frequency circuit system that can be suppressed.

To achieve the above object, a high-frequency circuit system according to the present invention includes an electron tube including a cathode electrode and a helix,
A phase comparator that outputs a voltage corresponding to a phase difference between a first high-frequency signal input to the electron tube and a second high-frequency signal output from the electron tube;
Based on the output voltage of the phase comparator, when there is a phase change of the second high-frequency signal with respect to the first high-frequency signal, the phase of the first high-frequency signal and the phase of the second high-frequency signal are matched. A power supply device for controlling a DC voltage supplied between the cathode electrode and the helix;
Have

  According to the present invention, even when the phase of a high-frequency signal changes at high speed due to load fluctuation of an electron tube such as a traveling wave tube, the phase fluctuation can be suppressed.

It is a block diagram which shows the example of 1 structure of the high frequency circuit system of 1st Embodiment. It is a circuit diagram of the principal part of this embodiment which extracted and showed the regulator circuit from the high frequency circuit system shown in FIG. It is a schematic diagram which shows a mode that a helix voltage is stabilized by the regulator circuit shown in FIG. It is a block diagram which shows the example of 1 structure of the high frequency circuit system of 2nd Embodiment. It is a block diagram which shows the structure of the high frequency circuit system of background art. It is a circuit diagram which shows the structural example of the power supply device of background art. It is a circuit diagram which shows the other structural example of the power supply device of background art.

Next, the present invention will be described with reference to the drawings.
(First embodiment)
FIG. 1 is a block diagram illustrating a configuration example of the high-frequency circuit system according to the first embodiment.

  As shown in FIG. 1, the high-frequency circuit system according to the first embodiment includes a traveling wave tube (TWT) 1, a high-frequency signal (first high-frequency signal) input to the traveling-wave tube 1, and an output from the traveling-wave tube 1. The phase comparator 70 that outputs a voltage corresponding to the phase difference from the high-frequency signal (second high-frequency signal), and the phase of the first high-frequency signal input to the traveling wave tube 1 is advanced or delayed by a certain amount and output. When a predetermined DC voltage is supplied to each of the phase shifter 80 and each electrode of the traveling wave tube 1 and there is a phase change of the second high-frequency signal with respect to the first high-frequency signal based on the output voltage of the phase comparator 70, The power supply device 60 controls the helix voltage Ehel voltage supplied between the cathode electrode and the helix so that the phase of the first high-frequency signal and the phase of the second high-frequency signal coincide with each other.

  Note that the power supply device 60 shown in FIG. 1 shows only a circuit example of a helix power supply that generates the helix voltage Ehel. The power supply device 60 includes not only a helix power supply but also a collector power supply, an anode power supply, a heater power supply, etc. (not shown) as shown in FIG.

  The traveling wave tube 1 is, for example, a well-known electron tube shown in FIG. 5 that amplifies and outputs an input first high-frequency signal. The present invention can be applied not only to the traveling wave tube 1 but also to other electron tubes in which the phase of a high frequency (microwave) signal to be amplified is changed by the fluctuation of the helix voltage Ehel.

  A part of the first high-frequency signal input to the traveling wave tube 1 is demultiplexed and supplied to the phase shifter 80 using a directional coupler or the like. The phase shifter 80 advances or delays the phase of the input first high-frequency signal, so that the second high-frequency signal output from the traveling wave tube 1 during normal time (when there is no load fluctuation by the traveling wave tube 1) The first high-frequency signal having the same phase is output. The phase shifter 80 may have any known configuration as long as the phase of the input first high frequency signal can be electrically or mechanically changed.

  A part of the second high-frequency signal output from the traveling wave tube 1 is demultiplexed and supplied to the phase comparator 70 using a directional coupler or the like. The phase comparator 70 is supplied with the first high-frequency signal output from the phase shifter 80. The phase comparator 70 outputs a voltage that uniquely corresponds to the phase difference between the first high-frequency signal output from the phase shifter 80 and the second high-frequency signal output from the traveling wave tube 1. For example, by using the phase shifter 80, the phase comparator 70 outputs 0 [V] when the first high-frequency signal and the second high-frequency signal having the same phase are input, When the phase of the second high-frequency signal changes, a positive (or negative) DC voltage is output. The phase comparator 70 may have any configuration as long as it outputs a voltage corresponding to the phase difference between the two input signals. For example, the phase comparator 70 may output a DC voltage proportional to the phase difference or a DC voltage inversely proportional to the phase difference. May be output. For the phase comparator 70, a device applicable to the frequency of the high frequency signal to be amplified by the traveling wave tube 1 may be used. For example, it can be realized by a known mixer circuit.

  The power supply device 60 includes a transformer 100, a first rectifier circuit 110 that converts an AC voltage supplied from a commercial power source or the like into a DC voltage, and a DC voltage output from the first rectifier circuit 110 to an AC voltage having a predetermined frequency. The inverter 120 connected to the primary winding of the transformer 100 for conversion, the second rectifier circuit 130 for converting the AC voltage output from the secondary winding of the transformer 100 into a DC voltage, and the output of the second rectifier circuit 130 And a regulator circuit 140 that is inserted between the end and the helix of the traveling wave tube 1 and suppresses a phase change of the second high-frequency signal with respect to the first high-frequency signal.

  The regulator circuit 140 has a collector and an emitter connected in series between the output terminal of the second rectifier circuit 130 (the output terminal of the DC voltage supplied between the cathode electrode 11 and the helix 20) and the helix 20 of the traveling wave tube 1. A transistor Q1 connected, a Zener diode ZD1 connected in parallel with the collector / emitter of the transistor Q1, and a driver circuit 141 for driving (ON / OFF) the transistor Q1 based on the output voltage of the phase comparator 70 are provided. ing.

  For example, an element having a Zener voltage Vz of about 100 V is used for the Zener diode ZD1. The Zener voltage Vz may be determined in consideration of the amount of change in the helix voltage Ehel due to load variation and the withstand voltage between the collector and emitter of the transistor Q1.

  The transistor Q1 is normally turned off by the driver circuit 141, the helix voltage Ehel drops, the phase of the second high-frequency signal output from the traveling wave tube 1 changes, and two input signals are output from the phase comparator 70. When a voltage (direct current) corresponding to the phase difference is output, it is turned on. As the transistor Q1, a bipolar transistor may be used as shown in FIG. 1, or a field effect transistor (FET) may be used.

  Based on the output voltage of the phase comparator 70, the driver circuit 141 normally turns off the transistor Q1 and can turn on the transistor Q1 when the phase of the second high-frequency signal changes with respect to the first high-frequency signal. May be used.

  FIG. 1 shows a configuration example in which the power supply device 60 includes a circuit for stabilizing the helix voltage Ehel that divides the helix voltage Ehel using the resistor R and negatively feeds back to the inverter 120. Yes. Since such a circuit cannot follow when the helix voltage Ehel fluctuates rapidly as described above, it does not contribute to the effect of the present invention. However, in order to obtain a more stable helix voltage Ehel, it is desirable to provide a circuit for stabilizing the helix voltage Ehel by negatively feeding back the helix voltage Ehel to the inverter 120 as shown in FIG.

  Next, the operation of the high-frequency circuit system according to this embodiment will be described with reference to the drawings.

  FIG. 2 is a circuit diagram of the main part of the present embodiment shown by extracting the regulator circuit from the high-frequency circuit system shown in FIG. 1, and FIG. 3 shows how the helix voltage is stabilized by the regulator circuit shown in FIG. It is a schematic diagram shown. FIG. 3 schematically shows how the phase of the helix voltage Ehel and the high-frequency signal changes, and the voltage and phase values shown in FIG. 3 are merely examples. Further, “LO” of the anode voltage Ea shown in FIG. 3 indicates the same potential as the cathode electrode 11, and “HIGH” indicates a predetermined positive voltage with respect to the potential of the cathode electrode 11.

  As described above, the transistor Q1 included in the regulator circuit 140 is normally turned off because, for example, 0 V is output from the phase comparator 70. As shown in FIG. 2, since the Zener diode ZD1 is inserted between the second rectifier circuit 130 and the helix at this time, the second rectifier circuit 130 is interposed between the helix 20 of the traveling wave tube 1 and the cathode electrode 11. Is supplied with a helix voltage Ehel that is lowered by a Zener voltage Vz (for example, 100 V) of the Zener diode ZD1.

  Here, for example, as shown in FIG. 3A, when a predetermined positive voltage is applied to the anode electrode 40 of the traveling wave tube 1 in a step shape, the traveling wave tube 1 outputs a second high frequency signal in a step shape. As a result, the helix voltage Ehel drops due to a sudden decrease in the load (traveling wave tube 1), and the phase (RF phase) of the second high-frequency signal output from the traveling wave tube 1 changes.

  At this time, the phase comparator 70 outputs a voltage corresponding to the phase difference between the two input signals, that is, a voltage corresponding to the phase change of the second high-frequency signal with respect to the first high-frequency signal. Q1 is turned on. As a result, both ends of the Zener diode ZD1 are bypassed by the transistor Q1, and the output voltage of the second rectifier circuit 130 is output via the transistor Q1, so that the traveling wave tube 1 is connected to the traveling wave tube 1 as shown by the arrow in FIG. The supplied helix voltage Ehel increases. Further, as the helix voltage Ehel increases, the phase change of the high-frequency signal output from the traveling wave tube 1 is suppressed as shown by the arrow in FIG.

  When the transistor Q1 is turned on by the driver circuit 141, the traveling wave tube 1, the phase comparator 70, the driver circuit 141, and the transistor Q1 form a negative feedback loop. Therefore, the driver circuit 141 matches the phase of the second high-frequency signal output from the traveling wave tube 1 with the phase of the first high-frequency signal output from the phase shifter 80 so that the input voltage becomes 0V. Thus, the transistor Q1 is driven to adjust its output voltage.

  As shown in FIG. 1 and FIG. 2, the regulator circuit 140 has a simple configuration including only the driver circuit 141 and the transistor Q1 in the main signal path, and thus the phase change of the second high-frequency signal output from the traveling wave tube 1 The amount of delay of the negative feedback loop for correcting the error is small. Therefore, even when the phase of the second high-frequency signal output from the traveling wave tube 1 changes at high speed, the phase change is suppressed.

  The high-frequency circuit system of the present embodiment is configured to correct the helix voltage Ehel based on the phase change of the second high-frequency signal output from the traveling wave tube 1 with respect to the first high-frequency signal input to the traveling wave tube 1. As in Patent Document 2, the control is not performed in synchronization with the signal supplied to the anode electrode 40. Therefore, as shown in FIG. 3, the traveling wave tube 1 is applied not only when the stepped voltage is applied to the anode electrode 40 to output the second high-frequency signal from the traveling wave tube 1 in a burst shape, but also for other reasons. It is possible to cope with the case where the load due to the above changes rapidly and the phase of the second high-frequency signal changes.

Further, since the helix 20 of the traveling wave tube 1 is grounded as described above, the regulator circuit 140 shown in FIGS. 1 and 2 is a circuit element that operates with a relatively low DC voltage with respect to the ground potential. It can be realized using. Therefore, it is not necessary to use special circuit components that operate at a high voltage, and an increase in cost due to the provision of the regulator circuit 140 can be suppressed.
(Second Embodiment)
FIG. 4 is a block diagram illustrating a configuration example of the high-frequency circuit system according to the second embodiment.

  As shown in FIG. 4, the high frequency circuit system of the second embodiment demultiplexes the first high frequency signal input to the traveling wave tube 1 and directly supplies it to the phase comparator 70, and the input terminal of the regulator circuit 140. Is provided with a DC power supply 142 for applying a predetermined DC voltage. That is, the high-frequency circuit system of the second embodiment has a configuration that does not require the phase shifter 80 shown in FIG. Since other configurations are the same as those of the high-frequency circuit system according to the first embodiment, description thereof is omitted.

  In the high-frequency circuit system of the second embodiment shown in FIG. 4, the first high-frequency signal input to the traveling wave tube 1 and the second high-frequency signal output from the traveling wave tube 1 are normally output from the phase comparator 70. A DC voltage corresponding to the phase difference is output.

  The DC power supply 142 cancels the output voltage of the phase comparator 70 at the normal time (for example, the driver circuit 141) so that the transistor Q1 is turned off at the normal time and the transistor Q1 is turned on when the phase of the second high-frequency signal is changed. DC voltage is output (such that the voltage at the input terminal is 0V).

  Even in such a configuration, as in the high-frequency circuit system of the first embodiment shown in FIG. 1, since the transistor Q1 is normally turned off, the helix 20 and the cathode electrode 11 of the traveling wave tube 1 are turned off. In the meantime, a helix voltage Ehel that is lowered by a Zener voltage Vz (for example, 100 V) of the Zener diode ZD1 with respect to the output voltage of the second rectifier circuit 130 is supplied.

  Further, when the helix voltage Ehel falls due to a sudden decrease in the load (traveling wave tube 1) and the phase (RF phase) of the second high-frequency signal output from the traveling wave tube 1 changes, the phase comparator 70 A voltage corresponding to the phase change of the second high-frequency signal output from the traveling wave tube 1 is output, and the driver circuit 141 turns on the transistor Q1 to suppress the drop in the helix voltage Ehel and the phase change of the high-frequency signal. Is done.

  Therefore, the high-frequency circuit system of the second embodiment shown in FIG. 4 can also obtain the same effect as that of the first embodiment.

  Note that the DC power supply 142 shown in FIG. 4 can be provided in the regulator circuit 140 of the first embodiment shown in FIG. For example, when the phase of the first high-frequency signal output from the phase shifter 80 does not match the phase of the second high-frequency signal output from the traveling wave tube 1, the phase comparator 70 corresponds to the phase difference. DC voltage is output. Also in that case, the DC power supply 142 is configured to cancel the output voltage of the phase comparator 70 at the normal time so that the transistor Q1 is turned off at the normal time and the transistor Q1 is turned on at the time of the phase change of the second high-frequency signal. A voltage may be generated and supplied to the input terminal of the driver circuit 141.

DESCRIPTION OF SYMBOLS 1 Traveling wave tube 10 Electron gun 11 Cathode electrode 12 Heater 13 Wehnelt electrode 20 Helix 30 Collector electrode 40 Anode electrode 50 Electron beam 60 Power supply 61 Helix power supply 62 Collector power supply 63 Anode power supply 64 Heater power supply 70 Phase comparator 80 Phase shifter 100 Transformer 110 First rectifier circuit 120 Inverter 130 Second rectifier circuit 140 Regulator circuit 141 Driver circuit 142 DC power supply Q1 Transistor ZD1 Zener diode

Claims (5)

An electron tube with a cathode electrode and a helix;
A phase comparator that outputs a voltage corresponding to a phase difference between a first high-frequency signal input to the electron tube and a second high-frequency signal output from the electron tube;
Based on the output voltage of the phase comparator, when there is a phase change of the second high-frequency signal with respect to the first high-frequency signal, the phase of the first high-frequency signal and the phase of the second high-frequency signal are matched. A power supply device for controlling a DC voltage supplied between the cathode electrode and the helix;
A high frequency circuit system. A phase shifter that outputs the phase of the first high-frequency signal input to the electron tube after being advanced or delayed by a certain amount;
The phase comparator is
The high-frequency circuit system according to claim 1, wherein a voltage corresponding to a phase difference between the first high-frequency signal output from the phase shifter and the second high-frequency signal output from the electron tube is output. The power supply device
A transistor connected in series between an output terminal of a DC voltage supplied between the cathode electrode and the helix and the helix;
A Zener diode connected in parallel with the transistor;
A driver circuit for driving the transistor based on an output voltage of the phase comparator;
Having a regulator circuit with
The driver circuit is
Based on the output voltage of the phase comparator, when there is no phase change of the second high-frequency signal with respect to the first high-frequency signal, the Zener voltage of the Zener diode is dropped from a predetermined DC voltage between the cathode electrode and the helix. When the phase of the second high-frequency signal is changed with respect to the first high-frequency signal, the transistor is driven so that the phase of the first high-frequency signal matches the phase of the second high-frequency signal. The high-frequency circuit system according to claim 1. The regulator circuit is:
A DC power supply for generating a DC voltage for canceling a voltage output from the phase comparator when there is no phase change of the second high-frequency signal with respect to the first high-frequency signal, and supplying the DC voltage to the input terminal of the driver circuit; The high frequency circuit system according to claim 1, further comprising:   The high-frequency circuit system according to claim 1, wherein the helix is grounded.

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