JP2009277379A - Electronic tuning magnetron - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a high output microwave of a desired frequency with a fast response with a simple structure, and obtain an oscillation frequency of a wide variable range without arranging a switch element inside a tube bulb. <P>SOLUTION: A resonant cavity is formed by dividing the interior of the anode shell 2 into a plurality of pieces with an anode 3, a through-hole 11 formed on a wall face of a resonant cavity in the anode shell 2 is occluded, in a magnetron in which a cathode 1 is installed at the center of this anode shell 2. Then, a window 12 of a low dielectric loss material to hold the resonant cavity in a vacuum, a metal rod 14 connected to the outside of the anode shell 2 via an insulating body 15 in an inserted state into an electric field extended from this window 12, and a switch element part 18 of which one end is connected to this rod 14 and the other end is connected to the anode shell 2 are installed. By making a bias current flow in this switch element part 18, a resonant frequency of the resonant cavity is changed. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an electronically tuned magnetron that oscillates a microwave, and more particularly, to a magnetron configuration that has a simple structure and changes an oscillation frequency by an external electric signal.

  FIG. 12 shows a basic structure of a conventional magnetron. In the magnetron, a cathode 1 is disposed at the center, an anode shell 2 is provided concentrically with the cathode 1 on the outer side, and an internal space of the magnetron is defined. A plurality of anodes 3 are arranged so as to be divided into a plurality in the circumferential direction. That is, the anode 3 serves as a positive electrode with respect to the cathode 1 and at the same time serves as a resonator that determines the oscillation frequency, and thus forms a resonant cavity together with the inner wall of the anode shell 2.

  Further, in order to obtain the most stable π-mode oscillation of the magnetron, a linear metal conductor called a strap 4 is used, and every other anode 3 serving as a partition of the divided resonance cavity is connected. In the magnetron having such a structure, the oscillation frequency is determined by the reactance of the resonance cavity and the reactance of the strap 4.

  As described above, in the configuration of the magnetron shown in FIG. 12, the oscillation frequency is determined by the mechanical structure. Therefore, in order to change the frequency, the frequency cannot be changed unless the reactance determined from the mechanical structure is changed. It was. Non-patent document 1 (“MICROWAVE MAGNETRON” MIT Radiation Laboratory Series) p. There is one based on the principle shown in 562, which changes the frequency by inserting metal into the resonant cavity and changing the reactance of the resonant cavity. That is, by inserting metal inside the resonant cavity, the inductance of the resonator is increased, and particularly when inserted near the tip of the anode 3 which is the partition of the resonant cavity, the capacitance increases. As a result, the oscillation frequency is increased.

In addition to the resonance cavity described above, as a means for mechanical tuning, a method of bringing a metal close to the partition plate of the strap 4 and the anode 3 is shown in pages 569 to 572 of Non-Patent Document 1 below. ing.
Furthermore, as shown in the following Patent Document 1 (Japanese Patent Laid-Open No. 2000-3676) or Patent Document 2 (Japanese Patent Laid-Open No. 2006-100066), external resonance is provided outside the tube via a hole (or slit). By providing a cavity (or external space) and adjusting the position of the metal plate (or movable metal piece) arranged in the external resonant cavity by mechanical movement, the reactance of the resonant cavity from outside the tube is adjusted. There is a method of controlling the oscillation frequency by changing the oscillation frequency.
"MICROWAVE MAGNETRON" MIT Radiation Laboratory Series p.562, p.569-572) JP 2000-3676 JP 2006-100066 A US-3967155 JP-A-50-133863 WO-92 / 020088 Publication

  However, in Patent Document 1 and Patent Document 2 described above, a mechanical movable part is used as means for changing the frequency, and it is difficult to manufacture the movable part in an external resonant cavity that is evacuated. There is. Moreover, since the mechanical frequency variable means having a movable part has a slow response, there is no problem when the frequency is changed slowly, but a fast change such as when changing the frequency within one pulse, for example, several hundred nanometers. It is impossible to change the frequency at the second or the like.

  On the other hand, as an example of an electronically tuned magnetron, as shown in Patent Document 3 (US-3967155), a method is disclosed in which an electrode is provided in a tube and reactance is changed by space charge. Further, as shown in Patent Document 4 (Japanese Patent Laid-Open No. 50-133663) and Patent Document 5 (WO-92 / 020088), a switch element is disposed in the tube of a coaxial magnetron and is externally provided. There is disclosed a method of changing the frequency by changing the reactance of the resonant cavity by changing the conduction state of the switch element arranged inside the resonant cavity by the above signal.

  However, in these Patent Documents 3 to 5, it is necessary to manufacture a complicated switch element or the like inside a tube that is evacuated, and there are problems regarding manufacturing difficulty and cost. In a vacuum tube such as a magnetron, the characteristics change easily when the degree of vacuum deteriorates due to the generation of gas, so it is necessary to maintain a high degree of vacuum. Therefore, a material that easily generates gas cannot be used, and joining is brazed at a high temperature. Therefore, when the switch element is a semiconductor, it is difficult to fit it in a tube.

  Furthermore, when a part of the inside of the tube is short-circuited by the switch element, there is a drawback that the variable frequency range that can be changed by that is narrow. This is because the normal switch element can change the reactance only by a part of the resonator that is coupled to the original resonant cavity or the resonant cavity. To expand the frequency variable range, an expensive switch is required. It is necessary to use many elements. In addition, since the switch element usually has a capacitance, there is a problem that the response is deteriorated with respect to the bias voltage. When a plurality of switch elements are used, the capacity becomes large and a high-speed response is required. Cannot be used for modulation within a pulse.

  On the other hand, since the switching element is inserted into the part of the magnetron resonator as a synthetic resonance cavity as described above, the high-frequency resistance value greatly affects the resonance impedance of the magnetron, and the resonance Q is lowered. This will affect the basic characteristics. As a result, there is a problem that the change of the frequency fluctuation with respect to the magnetron load called the pulling characteristic is deteriorated. In addition, in the reliability quality of the magnetron, if a switching element is placed in the tube, it will be near the position where the electric field is minimum and the magnetic field is maximum when the magnetron is deteriorated or when an anode voltage pulse with a particularly fast rise is applied. Even when the switches are arranged, a high electric field is generated, and there is a case where the power durability of the switch element is broken.

  In addition, referring to the necessity of frequency tuning, there are a passive reason for ensuring stability against magnetron drift and an active reason for applying modulation. The drift of the oscillation frequency of the magnetron is called a current pushing characteristic and may change depending on the magnitude of the anode current. This frequency drift is considered to be caused by the fact that the amount of electrons jumping out of the cathode changes depending on the magnitude of the flowing anode current and the space charge changes.

Further, the change in the oscillation frequency of the magnetron is called a pulling characteristic and may be deteriorated due to a high frequency load fluctuation of the magnetron. That is, it is considered that the deterioration of the pulling characteristic is caused by the fact that the reactance of the resonance cavity of the magnetron is affected when the matching state with the load impedance of the magnetron is poor.
Further, in a magnetron, the resonant cavity may thermally expand due to the temperature around the mounting location or the heat generated by the magnetron confidence. In this case, the oscillation frequency increases when the temperature rises and decreases when cooled.

As described above, since the magnetron has a factor that causes the oscillation frequency to change, there is a possibility that the tuning may be lost, and it is desirable to stably perform variable control of the oscillation frequency.
In addition, when a microwave signal modulated using a magnetron is oscillated by a radar or the like and a reflected wave from a target is analyzed, the amount of information contained becomes enormous and the search performance of the radar is remarkably improved. This area is currently being studied to cover solid-state that is easy to modulate. However, no element that can efficiently oscillate a high output in the solid state has appeared.

  The present invention has been made in view of the above problems, and its purpose is not to use mechanical means having a movable part, but to have a simple structure, and a high-output microwave having a desired frequency can be generated by an external electric signal. It is possible to obtain an extremely fast response, and it is possible to obtain a wide variable range of oscillation frequency without placing a switch element inside the tube, and without disturbing productivity, a low-cost and highly reliable magnetron can be obtained. It is to provide.

In order to achieve the above object, an electronically tuned magnetron according to a first aspect of the present invention comprises a plurality of anodes forming a plurality of divided resonance cavities on the inner peripheral side of a cylindrical anode shell, and the anode shell. The cathode provided along the cylindrical axis direction of the central portion of the anode and the through hole formed in the wall of the resonant cavity of the anode shell are closed and the vacuum of the resonant cavity is maintained. A window of dielectric loss material, a rod-shaped metal disposed outside the anode shell in a state of being inserted into an electric field protruding from the window, and connected to the anode shell via an insulator, and the rod-shaped metal A switching element having one end connected to the metal and the other end connected to the anode shell, and changing a resonance frequency of the resonance cavity by flowing a bias current through the switching element. And wherein the door.
According to a second aspect of the present invention, there is provided an electronically tuned magnetron having a plurality of anodes forming a plurality of divided resonance cavities on an inner peripheral side of a cylindrical anode shell, and a central portion of the anode shell along a cylindrical axis direction thereof. A cathode of low dielectric loss material disposed in a state where the through hole formed in the wall of the resonant cavity of the anode shell is closed and the vacuum of the resonant cavity is maintained, and the through hole In a state of being inserted into an electric field extending from a hole, a rod-like shape is inserted and arranged between the window and the through hole in the wall from the outside of the anode shell, and is connected to the anode shell via an insulator. A switch element having one end connected to a portion of the rod-shaped metal exposed to the outside of the anode shell and the other end connected to the anode shell, and supplying a bias current to the switch element. Accordingly, characterized in that to change the resonance frequency of the resonant cavity.

According to a third aspect of the present invention, there is provided an electronically tuned magnetron including a plurality of anodes forming a resonance cavity divided into a plurality of portions on an inner peripheral side of a cylindrical anode shell, and a central portion of the anode shell along a cylindrical axis direction thereof. A cathode of a low dielectric loss material disposed in a state where the through hole formed in the wall of the resonant cavity of the anode shell is closed and the vacuum of the resonant cavity is maintained, and the window Including a metal pattern (band-shaped) formed on the window surface of the window as a dielectric substrate in a state where the window is inserted into an electric field extending from the switch, and a switch element connected to one end of the metal pattern, The resonant frequency of the resonant cavity is changed by passing a bias current through the switch element.
According to a fourth aspect of the present invention, there is provided an electronically tuned magnetron having a plurality of anodes forming a resonance cavity divided into a plurality of portions on an inner peripheral side of a cylindrical anode shell, and a center portion of the anode shell along a cylindrical axis direction thereof. A cathode of a low dielectric loss material disposed in a state where the through hole formed in the wall of the resonant cavity of the anode shell is closed and the vacuum of the resonant cavity is maintained, and the window And a switch element having one end connected to the outer end of the metal wire and the other end connected to the anode shell. The resonance frequency of the resonance cavity is changed by flowing a bias current through the switch element.

The electronically tuned magnetron according to claim 5 uses a bias control circuit for passing a current to the switch element, and the bias current of the bias control circuit is synchronized with the pulse anode current of the magnetron and is changed within the pulse of the anode current. The bias current is applied to the switch element.
An electronically tuned magnetron according to claim 6 uses a bias control circuit for passing a current to the switch element and a detection circuit for detecting an oscillation frequency of the magnetron, and compares the oscillation frequency detected by the detection circuit with a reference frequency. A bias current formed in this manner is applied to the switch element.

According to the configuration of the present invention, for example, a switching element composed of a PIN diode is arranged outside the anode shell (resonance cavity), and the frequency can be freely changed by an electric signal from the outside to use an electronic tuning magnetron. it can.
Further, in the configuration of claims 1 to 3, when a bias current flows and the switch element is not turned off, the rod-like metal or metal pattern is in a state of floating from the potential of the anode shell and protrudes from the window. Although the electric field is not blocked, when the bias current flows, the switch element is turned on, and the electric field protruding from the window is blocked by the rod-shaped metal or metal pattern, and the reactance of the resonator is changed. Change. Therefore, the resonance frequency can be variably controlled by supplying a controlled bias current to the switch element.

  According to the fourth aspect of the present invention, when the switch element is turned off, the metal body in the resonant cavity has no effect, but when a bias current flows, the switch element is turned on and the metal body causes the resonant cavity to be turned on. As a result, the resonance frequency is variably controlled. Also in this case, the resonance frequency is variably controlled by the bias current applied to the switch element.

  According to the electronically tuned magnetron of the present invention, a high-output microwave having a desired frequency can be obtained with an extremely fast response by an electric signal from the outside with a simple structure regardless of mechanical means having a movable part. In addition, it is possible to obtain an oscillation frequency with a wide variable range without disposing the switch element inside the tube, and to provide a low-cost and highly reliable magnetron without impeding productivity. . In addition, it is easy to select a frequency to prevent magnetron frequency drift and prevent interference. By modulating the pulse, a large amount of compressed information can be obtained at low output, and the occupied frequency bandwidth can be narrowed. There is also an effect of becoming.

  1 and 2 show the configuration of an electronically tuned magnetron according to a first embodiment of the present invention. In FIG. 1, the magnetron has a cathode 1 disposed at the center and an anode shell 2 concentrically with the cathode 1 on the outside, as in the basic structure shown in FIG. 12, and a space in the anode shell 2. A plurality of anodes 3 are arranged so as to be divided into a plurality in the circumferential direction. The anode 3 becomes a positive electrode with respect to the cathode 1 and at the same time forms a resonant cavity (resonator) together with the inner wall of the anode shell 2. In addition, every other anode 3 for partitioning the divided resonant cavities is connected by a strap 4 made of a linear metal conductor so that the π-mode oscillation of the magnetron is most stable.

  In the first embodiment, for example, a through hole 11 is formed in the anode shell 4 which is the wall surface of the resonant cavity, and the outside of the through hole 11 is closed to maintain the vacuum of the resonant cavity (magnetron tube). A window 12 made of a low dielectric loss material such as ceramic or glass is arranged so as to be in an airtight state. Further, a metal rod (rod-like metal) 14 is disposed outside the window 12 so as to block a part of the front surface of the window 12, and one end of the rod 14 is electrically insulated through an insulator 15. In this state, the anode shell 2 is supported by a support (metal) 16a, and one end of the rod 14 also functions as a terminal 14T for applying a bias voltage. Furthermore, the other end of the rod 14 is connected to one end of a switch element unit 18 made of a PIN diode, and the other end of the switch element unit 18 is electrically connected to the anode shell 2 by a support (metal) 16b (short circuit). )

  According to the first embodiment having such a structure, the electric field of the resonant cavity protrudes to the outside through the through hole 11 and the window 12. Normally, when the bias current is not flowing, the switch element portion 18 is turned off, and the protruding electric field is not blocked because the rod 14 is floating from the potential of the anode shell 2, and the resonance frequency is that of the original resonance cavity. The frequency is higher than the frequency. That is, the reactance outside the tube acts on the reactance in the anode shell 2 which is a tube.

  Next, when a bias current is applied and a bias voltage is applied between the anode shell 2 and the terminal 14T in order to turn on the switch element unit 18, the rod 14 is short-circuited to the anode shell 2 at a high frequency, and the switch element unit 18 and the rod 14 prevents the electric field from protruding from the window 12 while increasing the RF resistance as the bias current increases. As a result, the oscillation frequency decreases as the bias current increases. One conventional method is to couple another resonator to the main resonance cavity of the magnetron, change the reactance of the other resonator, and change the resonance frequency of the combined resonance cavity. The configuration of (2) does not change the resonance frequency by coupling another resonator, but changes the electric field (coupling degree of the window 12) extending from the resonance cavity without providing another resonator. Thus, the resonance frequency of the single resonance cavity itself is changed.

  FIG. 3 shows the configuration of the magnetron according to the second embodiment, and this second embodiment is obtained by changing the short-circuit position with respect to the anode shell of the metal rod. That is, the switch element portion 18 is disposed in the middle of the rod 20, and one end of the rod 20 on the support 16b side is floated and connected via the insulator 15, and this one end functions as a bias supply terminal 20T. The other end is electrically connected to the anode shell 2 through the support 16a. Also in the second embodiment, by supplying a bias current from the terminal 20T to the switch element portion 18, the oscillation frequency can be made variable as in the case of the first embodiment.

  FIG. 4 shows the configuration of the magnetron of the third embodiment. In the third embodiment, a metal rod is arranged inside the anode shell. As shown in FIG. 4, a through hole 21 is provided on the wall surface of the anode shell 2 forming the resonance cavity, and a window 12 of a low dielectric loss material is provided outside the through hole 21. The window 12 is attached so as to maintain an airtight state that maintains the vacuum of the resonant cavity. A metal rod 14 is inserted between the window 12 and the through hole 21 in the wall surface from the outside of the anode shell 2, and the rod 14 is placed in the electric field protruding from the through hole 21 (through hole 22 and Arranged so as to block a part of the window 12).

  The rod 14 is received by, for example, an insulator 23 arranged as shown in the figure, insulated from the anode shell 2 and supported by a support 16b or the like, and one end of the rod 14 on the support 16a side is a bias supply terminal 14T. Function as. The other end of the rod 14 is exposed to the outside, and one end of the switch element unit 18 is connected to the exposed end. The other end of the switch element unit 18 is electrically connected to the anode shell 2. (Or connected to the anode shell 2 via the support 16b).

  Also in the third embodiment, a bias is supplied from the terminal 14T, the switch element unit 18 is turned on / off, and a controlled bias current is applied to the rod 14 so as to pass through the through hole 21 and the window 12. The overhanging electric field can be changed, whereby the oscillation frequency can be made variable as in the first embodiment.

  FIG. 5 shows the structure of a magnetron according to the fourth embodiment. In the fourth embodiment, a metal pattern is formed on a window. In the fourth embodiment, for example, a window 25 for closing the through hole 21 is provided outside the through hole 21 formed inside the wall surface of the anode shell 2 (similar to the window of FIG. 6A). The window 25 is made of, for example, a dielectric substrate made of ceramic (which is also a low dielectric loss material), and is attached so as to hold the vacuum of the magnetron tube. As shown in FIG. 5B, a band-like (linear) metal pattern 27 instead of a rod-like metal is formed on the surface of the window 25 as the dielectric substrate, and a part of the through-hole 21 and the window 25. A switch element 29 is mounted between one end of the strip-shaped metal pattern 27 and a terminal part (metal pattern) 28, and a terminal 30 for applying a bias to the terminal part 28 is formed. Is attached. Further, the other end 27 a of the strip-shaped metal pattern 27 is short-circuited to the anode shell 2.

  According to the fourth embodiment, by applying a bias voltage between the terminal 30 and the anode shell 2, a bias current flows from the switch element portion 29 to the metal pattern 27, and this amount of current is controlled. By changing the overhang of the electric field, the oscillation frequency can be variably controlled.

  FIG. 6 shows the structure of a magnetron according to the fifth embodiment. In the fifth embodiment, a metal body is inserted into a resonant cavity of the anode shell through a window. As shown in FIG. 6B, for example, a window 25 that closes the through hole 21 is provided outside the through hole 21 formed inside the wall surface of the anode shell 2. It is made of a low dielectric loss material such as glass and is attached in a state where the vacuum of the magnetron tube (resonance cavity) is maintained. A metal probe (metal body) 32 is arranged so as not to contact the components of the resonance cavity in the anode shell 2, and the probe 32 is led out of the tube through the window 25 by the metal wire 33. The other end of the metal wire 33 is connected to the switch element unit 18 via the terminal 34. The other end of the switch element portion 18 is electrically connected (short-circuited) to the anode shell 2 by a support (metal) 35.

  According to the configuration of the fifth embodiment as described above, when a bias is supplied to the switch element unit 18 between the anode shell 2 and the terminal 34, the presence of the probe 32 causes the inside of the resonance cavity of the anode shell 2 to exist. The inductance will change, and the oscillation frequency can be changed accordingly. Therefore, by variably adjusting the bias current to the switch element unit 18, the oscillation frequency can be variably controlled as in the first embodiment.

  In the first to fourth embodiments described above, when the X-band magnetron is employed, the through holes 11 and 21 are formed in a square or circular shape having a height of 4 to 10 mm and a width of 0.6 to 5 mm. If so, the electric field can be extended. The windows 12 and 25 may be made of a material having a small dielectric loss at the oscillation frequency, such as mica or a ceramic material. The thickness of the windows 12 and 25 is preferably about 0.3 to 3 mm. It is necessary to withstand the pressure for maintaining the vacuum. Further, the thickness of the rods 14 and 20 is effectively 0.5 to 2.5 mm, and the switch element portion 18 preferably uses a PIN diode, and can operate at a low voltage of 10V or less.

FIG. 7 shows an example of the configuration of the switch element unit 18. As shown in the figure, the switch element unit 18 includes, for example, a PIN diode D ₁ , a PIN diode D ₂ , a resistor R ₁ , and a PIN diode D _3. Are arranged in parallel. According to such a switch element unit 18, fast switching characteristics can be obtained. Accordingly, if a bias current is supplied, high-speed response of several tens of ns is possible. Such high-speed response cannot be realized in a state where a large number of switch elements are used and the capacitance is high as in the prior art. In addition, when the frequency variable range of the embodiment is manufactured under the above conditions, a variable range of 30 MHz or more can be secured, and a sufficient frequency can be obtained without changing a wide range of reactance using a large number of switch elements as in the past. A variable range is obtained.

  FIG. 8 shows changes in bias current (mA) and oscillation frequency (MHz) in an example of the embodiment, which is an example in which a bias voltage is applied to an X-band electronically tuned magnetron. As a result, the frequency changed by 40 MHz. In addition, since the current required for the control (change) of the bias current is as small as about 100 mA and the voltage is low, the control circuit can be manufactured very easily.

  FIG. 9 shows an embodiment of a bias control (driving) circuit in the case where the electronic tuning magnetron of the above embodiment is used for a radar or the like. The electronic tuning magnetron 37 of this example includes a key of the modulator 38. The evening power source 39 and the anode voltage source 40 are connected to perform self-excited oscillation. The microwave output used in the radar is often a pulse, and the modulator 38 generates an anode voltage in a pulse. When a signal synchronized with the pulse voltage is obtained and the tuning control circuit 41 changes the bias current for tuning in accordance with the synchronization signal, the electronic tuning magnetron 37 outputs the microwave output whose frequency has changed within the pulse. Is oscillated. That is, a modulated microwave output is obtained.

  FIG. 10 shows the waveforms of the respective parts of the above-mentioned embodiment of FIG. 9. As shown in FIG. 10A, an anode voltage is applied from the modulator 38 to the magnetron 37 by pulses. At the same time, as shown in FIG. 10B, the tuning control circuit 41 supplies, for example, a control voltage changed in a saw-tooth manner to the switch element units 18 and 29 based on a signal synchronized with the anode voltage pulse. . As a result, as shown in FIG. 10C, the magnetron 37 can obtain an oscillation frequency that changes in a sawtooth shape with a reverse inclination to that in FIG. 10B. The tuning control circuit 41 can form a control voltage in which a waveform other than the sawtooth waveform is freely changed by using the synchronization signal, thereby arbitrarily changing the modulation frequency of the electronic tuning magnetron 37. It becomes possible. According to such a configuration, it is possible to provide a radar or the like that can obtain a large amount of compressed information with low output by modulating the pulse, and it is possible to reduce the occupied frequency bandwidth. .

  FIG. 11 shows another embodiment of the bias control circuit of the electronic tuning magnetron according to the above embodiment. This embodiment feeds back the oscillation frequency, and detects the oscillation frequency of the electronic tuning magnetron 37. A frequency detection circuit 43 is provided. The signal corresponding to the frequency detected by the detection circuit 43 is compared with the signal of the reference frequency signal generation circuit 44 by the comparison circuit 45. The reference signal frequency may be changed with time, for example. It may be always constant. The tuning frequency control circuit 46 forms a bias control signal according to the comparison signal. By applying a bias current from the tuning frequency control circuit 46 to the switch element units 18 and 29, the electronic tuning magnetron In this example, a stable oscillation frequency can be output based on the fed back frequency.

  As described above, since the electronic tuning magnetron of the embodiment has the switch element portions 18 and 29 provided outside the tube, there is no limitation in manufacturing as a vacuum tube, and a particularly expensive coaxial magnetron or Therefore, it is not necessary to design a magnetron having a sub-resonance cavity with an old design, and a conventional magnetron having a simple configuration can be sufficiently used. In addition, as described above, it is possible to supply a microwave oscillation source that can be used by changing the frequency freely in a wide range with an external signal, measures against frequency drift of the magnetron, and frequency selection for interference prevention There is an advantage that becomes easier.

It is a perspective view which shows the structure of the electronic tuning magnetron which concerns on 1st Example of this invention. It is an upper surface (partial cross section) figure which shows the structure of the electronic tuning magnetron of 1st Example. It is a perspective view which shows the structure of the electronic tuning magnetron of 2nd Example. The structure of the electronic tuning magnetron of 3rd Example is shown, A figure (A) is a perspective view, A figure (B) is an upper surface (partial cross section) figure. The structure of the electronic tuning magnetron of 4th Example is shown, A figure (A) is a perspective view, A figure (B) is a front view of a window part. The structure of the electronic tuning magnetron of 5th Example is shown, A figure (A) is a perspective view, A figure (B) is a top view. It is a circuit diagram which shows the structure of the switch element part of an Example. It is a graph which shows the relationship between the bias current and oscillation frequency in the electronic tuning magnetron of an Example. It is a circuit diagram which shows an example of the bias control (drive) circuit of the electronic tuning magnetron of an Example. It is a wave form diagram which shows the operation | movement in each part of the Example of FIG. It is a circuit diagram which shows the other example of the bias control circuit of the electronic tuning magnetron of an Example. It is a figure which shows the structure of the conventional magnetron.

Explanation of symbols

1 ... cathode, 2 ... anode shell,
3 ... anode, 11, 21 ... through hole,
12, 25 ... window, 14, 20 ... rod (metal),
14T, 20T, 30, 34 ... terminals,
15, 23 ... insulator, 16a, 16b, 35 ... support (metal),
18, 29 ... switch element part, 27 ... metal pattern,
37 ... Magnetron.

Claims (6)

A plurality of anodes forming a resonant cavity divided into a plurality on the inner peripheral side of the cylindrical anode shell;
A cathode provided at the center of the anode shell along the cylindrical axis direction;
A low dielectric loss material window disposed in a state in which a through hole formed in the wall of the resonant cavity of the anode shell is closed and the vacuum of the resonant cavity is maintained;
A rod-shaped metal disposed outside the anode shell and connected to the anode shell via an insulator in a state of being inserted into an electric field protruding from the window;
A switch element having one end connected to the rod-shaped metal and the other end connected to the anode shell,
An electronically tuned magnetron, wherein a resonance current of the resonance cavity is changed by passing a bias current through the switch element. A plurality of anodes forming a resonant cavity divided into a plurality on the inner peripheral side of the cylindrical anode shell;
A cathode provided in the center of the anode shell along the cylindrical axis direction;
A low dielectric loss material window disposed in a state in which a through hole formed in the wall of the resonant cavity of the anode shell is closed and the vacuum of the resonant cavity is maintained;
Inserted between the window and the through hole in the wall from the outside of the anode shell in a state of being inserted into the electric field protruding from the through hole, and connected to the anode shell through an insulator. A rod-shaped metal,
A switch element having one end connected to a portion of the rod-shaped metal exposed to the outside of the anode shell and the other end connected to the anode shell,
An electronically tuned magnetron, wherein a resonance current of the resonance cavity is changed by passing a bias current through the switch element. A plurality of anodes forming a resonant cavity divided into a plurality on the inner peripheral side of the cylindrical anode shell;
A cathode provided at the center of the anode shell along the cylindrical axis direction;
A low dielectric loss material window disposed in a state in which a through hole formed in the wall of the resonant cavity of the anode shell is closed and the vacuum of the resonant cavity is maintained;
In a state where it is inserted into an electric field protruding from this window, the window is used as a dielectric substrate and a metal pattern is formed on the window surface;
A switch element connected to one end of the metal pattern,
An electronically tuned magnetron, wherein a resonance current of the resonance cavity is changed by passing a bias current through the switch element. A plurality of anodes forming a resonant cavity divided into a plurality on the inner peripheral side of the cylindrical anode shell;
A cathode provided at the center of the anode shell along the cylindrical axis direction;
A low dielectric loss material window disposed in a state in which a through hole formed in the wall of the resonant cavity of the anode shell is closed and the vacuum of the resonant cavity is maintained;
A metal wire disposed in a state of penetrating the window from the outside and reaching the resonance cavity;
A switch element having one end connected to the outer end of the metal wire and the other end connected to the anode shell,
An electronically tuned magnetron, wherein a resonance current of the resonance cavity is changed by supplying a bias current to the switch element.   A bias control circuit for passing a current to the switch element is used. The bias current of the bias control circuit is synchronized with the pulse anode current of the magnetron, and a bias current changed within the pulse of the anode current is given to the switch element. The electronically tuned magnetron according to claim 1, wherein:   A bias control circuit for passing current to the switch element and a detection circuit for detecting the oscillation frequency of the magnetron are used, and a bias current formed by comparing the oscillation frequency detected by the detection circuit with a reference frequency is used as the switch element. The electronic tuning magnetron according to claim 1, wherein the electronic tuning magnetron is provided.

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