Obtain electronic efficiency from twocavity klystron. Klystron amplification, power output, and efficiency can be greatly improved by the addition of intermediate cavities between the input and output cavities of the basic klystron. The two cavity klystron utilizes an electron source heater, an anode, and a cathode like a conventional vacuum tube. It is a lowpower device used primarily for two purposes. I am reading two cavity klystrons but not able to understand at all. The vacuum tube consists of a cathode, which is heated by a filament. Between the cavities around the glass envelope a magnet is used in order to keep the electron beam in the center and in concentrated form at the end inside the glass envelope. Microwave engineering cavity klystron tutorialspoint. There is anode used to attract the electrons emitted from the cathode. Z2391g cv2187 the z2391g is a reflex klystron developed for use as a frequency modulated transmitter and capable of delivering an output of approximately one watt. These will set up a field in the third cavity, which produces more concentrated bunches and. Sep 27, 2017 in this video, i have explained two cavity klystron amplifier with following points 1.
Electrons in a klystron are accelerated to a controlled speed by the application of several hundred volts. Microwave engineering imp qusts mw important questions. Jul 31, 2018 the two cavity klystron utilizes an electron source heater, an anode, and a cathode like a conventional vacuum tube. Firstly, as we know that klystrons are used as amplifiers for microwave frequency and conventional vaccum tubes cant be used due to interelectrode capacitance and lead inductance effect,but though microwave signals can be amplified by klystrons is there any limitation to. Amplification of such two cavity klystron is low and hence multi cavity klystrons are used. It also utilizes a collector element at the end of the electron stream. Eaton a method is shown by which the twocavity ballistic theory. Additional cavities serve to velocitymodulate the electron beam and produce an increase in the energy available at the output. Impedancebased analysis of the relativistic klystron and. The klystron was the first embodiment of the velocity modulation principle. When used as an amplifier, the weak microwave signal to be amplified is applied to the buncher cavity through a coaxial cable or waveguide, and the amplified signal is extracted. The reflex klystron is a single cavity variable frequency timebase generator of low power and efficiency the twocavity klystron is a widely used microwave. Us2944183a us636261a us63626157a us2944183a us 2944183 a us2944183 a us 2944183a us 636261 a us636261 a us 636261a us 63626157 a us63626157 a us 63626157a us 2944183 a us2944183 a us 2944183a authority us united states prior art keywords cavity coupling secondary iris resonator prior art date 19570125 legal status the legal status is an assumption and is not a legal.
Reflex klystron consists of an electron gun, a cathode filament, an anode cavity, and an electrode at the cathode potential. The simplest klystron tube is the twocavity klystron. A three cavity klystron is illustrated in figure 28. Stability analysis of cband 500kw klystron with multi. It is given the name reflex klystron because of its reflex action of electron beam. Two forms of such a device, also called linear beam klystron, are given in the following figure. A klystron is a microwave vacuum tube using cavity resonators to produce velocity modulation of the electron beam and produce amplification. Amplification of such twocavity klystron is low and hence multicavity klystrons are used. Two cavity klystron amplifier download 21 sep a klystron is a vacuum tube that can be used either as a generator or as an amplifier or as an oscillator, at microwave klystron. It is typically used as a highpower frequency source in such applications as particle accelerators, uhf tv transmission and satellite earth. The frequency of operation of a klystron is set by the sizes of the input and output cavities.
The velocities of electrons emitted from the cathode are modulated to produce a densitymodulated electron beam. The ranges of all these voltages are given in the specification data sheet. This section will explain the basic operation of the most widely used microwave tubes, including klystrons, travelingwave tubes, backwardwave oscillators, magnetrons, and crossedfield amplifiers. Two cavity klystron amplifiers working, amplification and applegate diagram by engineering funda duration. The two cavity klystron in figure 27a and b may be used either as an oscillator or an amplifier. The multi cavity klystron consist of a glass envelope in which there is an electron gun composed of heater and cathode. Multicavity power klystrons repeller klystron two cavity klystron. Microwave engineering imp qusts pdf file mw important questions please find the attached pdf file of microwave engineering important questions bank. Two cavity klystron amplifiers working, amplification and. It has two microwave cavity resonators the catcher and the buncher. Klystron tube article about klystron tube by the free. Other precautions taken when tuning a klystron include using. The two cavity klystron in figure 27 may be used either as an oscillator or an amplifier.
In this klystron, a single pair of grids does the functions of both the buncher and the catcher grids. Introduction to the twocavity klystron amplifier technical. Klystron tube 2k25 the klystron tube 2k25 is a single cavity variable frequency microwave generator of low power and low efficiency. Input cavity is the buncher, output cavity is the catcher.
A klystron tube makes use of speedcontrolled streams of electrons that pass through a resonating cavity. Firstly, as we know that klystrons are used as amplifiers for microwave frequency and conventional vaccum tubes cant be used due to interelectrode capacitance and lead. Since all intermediate cavities in a multicavity klystron operate in the same manner, a representative three cavity klystron will be discussed. The electrons are originally accelerated to high velocity by a potential of several hundred volts and enter a narrow gap that forms part of a cavity resonator system see. Download download reflex klystron operation pdf read online read online reflex klystron operation pdf. There are two cavities known as buncher and catcher cavity. The nonlinear characteristics of klystron amplifiers d.
In this video, i have explained two cavity klystron amplifier with following points 1. The electrons are originally accelerated to high velocity by a potential of several hundred volts and enter a narrow gap that forms part of a cavity resonator system see figure, where they are acted upon by a radiofrequency field, which causes a bunchingup effect. The brothers russell and sigurd varian of stanford university are the. The frequency is primarily determined by the dimension of resonant cavity.
Microwave engineering reflex klystron tutorialspoint. The heater boils off electrons when heated and the electrons are ejected from the cathode and accelerate towards the anode due to the high dc potential. Microwave tubes perform the same functions of generation and amplification in the microwave portion of the frequency spectrum that vacuum tubes perform at lower frequencies. Jun 02, 2014 i am reading two cavity klystrons but not able to understand at all. Difference between two cavity klystron and reflex klystron.
Draw the equivalent circuit diagram of a reflex klystron. The simplest klystron tube is the two cavity klystron. A sutton tube, or reflex klystron, is a type of vacuum tube used to generate microwaves. The helix travelingwave tube twt, the coupledcavity twt, the forwardwave am plifier fwa, and the backwardwave amplifier and oscillator bwa and bwo are also 0type tubes, but they have nonresonant periodic structures for electron inter actions. Klystron article about klystron by the free dictionary. At a very high temperature, the cathode emits electrons. The following figure depicts an example of multicavity klystron amplifier. A klystron uses one or more special cavities, which modulate the electric field around the axis the tube. A reflex klystron consists of an electron gun, a cavity with a pair of grids and a repeller plate as shown in the above diagram. Klystron, magnetron and twt force electromagnetism. Due to the number of the resonant cavities klystrons are divided up into. The catcher grids are placed along the beam at a point where the bunches are fully formed.
Since all intermediate cavities in a multicavity klystron operate in the same manner, a. Impedancebased analysis of the relativistic klystron and the coupledcavity freeelectron laser twobeam accelerator. The electron gun emits the electron beam, which passes through the gap in the anode cavity. Buncher modulates the velocity of the electron beam klystron tubes klystron tube is a vacuum tube that can be operated either as an oscillator or as an amplifier at microwave frequencies.
It is known by this name due to its reflex action of electron beam. Cavity test has demonstrated the use of high power rf vector modulators to control multiple rf cavities driven by a single high power klystron to accelerate a nonrelativistic beam. This is being done by simulating klystron performances for various cavity parameters including the number of cavities, intercavity distance, and cavity tuning frequencies. P2 shows the relationship between output power, frequency and reflector voltage.
By lowering the qs of the cavities and by introducing intermediate cavities, wider bandwidth operation can be achieved. The klystron was invented at stanford university in 1937 and originally used as the oscillator in radar receivers during world war ii. Other articles where twocavity klystron is discussed. In this tube there are two microwave cavity resonators, the catcher and the buncher. Jan 07, 2019 a reflex klystron consists of an electron gun, a cavity with a pair of grids and a repeller plate as shown in the above diagram. Klystron a klystron is a vacuum tube that can be used either as a generator or amplifier of power at low frequency. Klystron, thermionic electron tube that generates or amplifies microwaves by controlling the speed of a stream of electrons. Us2944183a internal cavity reflex klystron tuned by a.
Mar 02, 2018 two cavity klystron amplifiers working, amplification and applegate diagram by engineering funda duration. Klystron multi cavity klystron, reflex klystron, working. Two cavity klystron amplifiers working, amplification. Pdf recent progress in relativistic klystron research. Klystron an ultrahighfrequency electronic vacuum device in which a steady stream. The feedback path provides energy of the proper delay and phase relationship to sustain oscillations. After the electron gun there are two focusing electrodes used to keep the electron beam in the center around the glass envelope. Z239 klystron two cavity klystron klystron reflex cv2187 two cavity resonator cavity resonator text. The difference between reflex and twomulti cavity klystron is that, reflex klystron uses single cavity for modulationdemodulation. The location is determined by the transit time of the bunches at the. Download fulltext pdf complex dynamics of a twocavity klystron oscillator with delayed feedback conference paper pdf available may 2004 with 71 reads. The main difference between two cavity reflex klystron amplifier.
The configuration shown in the figure is correct for oscillator operation. A klystron is a specialized linearbeam vacuum tube evacuated electron tube the name klystron comes from the stem form. Caryotakis, performance of a 150mw sband klystron, aip conf. It is different from the two or multi cavity klystron because it uses a single cavity for modulation or demodulation.
Functional and schematic diagram of a twocavity klystron. The following figure depicts an example of multi cavity klystron amplifier. Oct 01, 2014 0type tube is the twocavity klystron, and it is followed by the reflex klystron. The sixcavity test demonstrated acceleration of beam. Klystron and microwave department capabilities and xband.
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