Klystron amplifier vacuum tube electrical engineering. A klystron is used either as an amplifier in the microwave region or as an oscillator. Mwe unit 3 topic 36 two cavity klystron amplifier duration. Oct 01, 2014 0type tube is the twocavity klystron, and it is followed by the reflex klystron. The information about klystron amplifier was influenced by the. Electrons emitted by the cathode are accelerated by the anode toward the input cavity. Diagram of a two cavity klystron, used as an amplifier and rf signal source at microwave frequencies, and also as an oscillator. Lowpower klystrons are used as oscillators in terrestrial microwave relay communications links, while highpower klystrons are used as output tubes in uhf television. Other articles where twocavity klystron is discussed. A two cavity klystron tube is a a velocity modulated tube b frequency modulated tube c amplitude modulated tube d simple triode.
It is given the name reflex klystron because of its reflex action of electron beam. Sandalov msu, moscow, russia abstract the necessity to create the rf sources operating in twofrequency mode is supported by the proposals concerning the suppression of the emittance growth generated inside the rf. The necessity to create the rf sources operating in twofrequency mode is supported by the proposals concerning the suppression of the emittance growth generated inside the rf gun 1 and the possibility to increase the limited accelerated charge 2 by involving into the interaction with the beam, in addition to the. The basic process by which a twocavity klystron amplifier operates is as follows. Amplification of such twocavity klystron is low and hence multicavity klystrons are used. Stability analysis of cband 500kw klystron with multicell. The following quantity is not required in the calculation of q of a cavity resonator.
The input and output are taken from the tube via resonant cavities. Connectlosb 41pu wvguino the output of the 8562 klystron, klystron. Since all intermediate cavities in a multicavity klystron operate in the same manner, a. The bunching cavities regulate the speed of the electrons so that they arrive in bunches at the output cavity. The bunches of electrons excite microwaves in the output cavity of the klystron. Klystron multi cavity klystron, reflex klystron, working. Klystrons article about klystrons by the free dictionary.
Pdf complex dynamics of a doublecavity delayed feedback. The simplest klystron tube is the two cavity klystron. Experimental study of complex dynamics in a delayedfeedback multiple cavity klystron selfoscillator. The location is chosen because maximum energy transfer to the output catcher cavity occurs when the electrostatic field is of the correct polarity to slow down the electron bunches. With the signal applied in the first cavity, we get weak bunches in the second cavity. 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. There are few intermediate cavities used between buncher cavity and catcher cavity. This name is given by the name of its inventor robert sutton, it allow the passage of electron beam through a single resonant cavity. 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. Reflex klystron is a lowpower, lowefficiency microwave oscillator another tube based on velocity modulation, and used to generate microwave energy, it contain cathod. The two cavity klystron in figure 2 7a and b may be used either as an oscillator or an amplifier. Ds58220411a l5822 linear accelerator klystron amplifier. Diagram of a twocavity klystron, used as an amplifier and rf.
This is widely used in application where variable frequency is desired as. 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. In font of cavity resonator a huge crowed of electrons assembles and excites cavity, the oscillation it the cavity takes place and hence we get the r. A two cavity klystron tube is a engineering questions.
This embodiment results in highpowered klystrons capable at working. Zweikammerklystron the twocavity klystron is a widely used microwave amplifier operated by the principles of velocity and density modulation. For use as an amplifier, a klystron receives microwave energy at an input cavity through which the electron beam passes. Since the cavities were fixtuned and not adjustable after the assembly of the tube, no estimate of the effect of stagger tuning could be made. Klystron modes measurement of klystron characteristics. When switch on the circuit, the electrons starts emitting from the cathode. Figure 114 schematically shows the principal features of a two cavity klystron amplifier.
Reflex klystron reflex klystron is a single cavity variable frequency generator of low power and low efficiency. Signal from the output cavity is measured by a spectrum analyzer attached to the output waveguide. The difference between reflex and twomulti cavity klystron is that, reflex klystron uses single cavity for modulationdemodulation. Reflex klystron consists of an electron gun, a cathode filament, an anode cavity, and an electrode at the cathode potential. Experimental multiple klystron the tube described in sec. Contents introduction construction working reflex klystron oscillator applications 3. The main characteristics of a delayedfeedback multiple cavity klystron oscillator with. So lets see 2 cavity klystron amplifier first two cavity klystron amplifier 2 cavity klystron amplifier. The complex dynamics of a model double cavity delayed feedback klystron oscillator is considered. Difference between two cavity klystron and reflex klystron. Figure 1 shows a segment of the klystron resonator system in which a twogap resonator in the drift tube 3 is located between two main bunching onegap resonators 1, 2 of the klystron. The principle of velocityvariation, first used in heil oscillators, was also used in other microwave amplifying and oscillating tubes.
Work supported by department of energy contract deac0376sf00515. The catcher grids are placed along the beam at a point where the bunches are fully formed. Us4591799a high power klystron amplifier for supplying a. The two cavity klystron utilizes an electron source heater, an anode, and a cathode like a conventional vacuum tube. A klystron is a specialized linearbeam vacuum tube evacuated electron tube the name klystron comes from the stem form. The microwave energy modulates the velocities of electrons in the beam, which then enters a drift space. The inventors of the klystron are two brothers namely sigurd varian and russel from the university of stanford in the year 1937, and available in the year 1939. Feb 18, 2016 two cavity klystron amplifier s working, amplification and applegate diagram by engineering funda duration. The brothers russell and sigurd varian of stanford university are. The khpa shall consists of an rf amplifier chain including a klystron operating in. Klystron works on the principle of velocity modulation of electrons. Introduction a klystron is a vacuum tube that can be used either as a generator or as an. Reflex klystron amplifier, microwave klystron amplifier. In most linac applications, the klystron is used as an amplifier, so an input signal is required.
In this problem the gain of a klystron is proportional to the cavity shunt resistance r sh, while bandwidth proportional to the cavity 1q 0, so that r sh q 0 is a useful figure of merit in describing the effect of the each cavity on the gainbandwidth product of overall amplifier. These include the two cavity amplifier or oscilator, the reflex klystron, and the multicavity high power amplifier. Diagram of a twocavity klystron, used as an amplifier and. An electron beam is formed in an electron gun and passed through the gaps associated with the two cavities fig. Jul 31, 2018 technical article introduction to the two cavity klystron amplifier july 31, 2018 by mark mitchell klystron amplifiers are used in a variety of industries, including satellite systems, television broadcasting, radar, particle accelerators, and in the medical field. To make an oscillator, the output cavity can be coupled to the input cavitys with a coaxial cable or waveguide. The klystron was the first embodiment of the velocity modulation principle. The same method has been applied to tuning measurement of a diode pulsed klystron, e3712.
Amplification of such two cavity klystron is low and hence multi cavity klystrons are used. The following figure depicts an example of multicavity klystron amplifier. Cavity of a repeller klystron another tube based on velocity modulation, and used to generate microwave energy, is the reflex klystron repeller klystron. Comparison has been made with the results in normal triode operation and has shown a good agreement. Diagram of a twocavity klystron, used as an amplifier and rf signal source at microwave frequencies, and also as an oscillator. Tuning measurement of multicavity klystrons in diode mode. A power converter system 4 supplies the amplifier modules with dc power. The klystron tube is also known as a velocity modulated tube. Employs a power saver feature to optimize khpa efficiency to meet your operating condition. So lets see 2 cavity klystron amplifier first two cavity klystron amplifier 2 cavity klystron amplifier works on the following principles.
Citeseerx document details isaac councill, lee giles, pradeep teregowda. Complex dynamics of a doublecavity delayed feedback klystron oscillator article pdf available in technical physics 511. A klystron tube is generated the microwave frequencies, this can be used as amplifier or oscillator of the microwave signals. Thus basically klystron amplifiers possess less power than their counterparts magnetron and travelling wave tube.
Additional cavities serve to velocitymodulate the electron beam and produce an increase in the energy available at the output. The following figure depicts an example of multi cavity klystron amplifier. Two cavity klystron amplifiers working, amplification and applegate diagram by engineering funda duration. The selfoscillation and stationary oscillation conditions are analyzed theoretically. The function of the catcher grids is to absorb energy from the electron beam. Operation is similar to that of a klystronexcept that coupledcavity twts are designed with attenuation between the slowwave structure instead of a drift tube. This field supplies the image of the voltage at the terminals of the interaction gap. 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 from the catcher cavity. Introduction to the twocavity klystron amplifier technical. Experiment4 study of the characteristics of the klystron tube. A klystron is a specialized linearbeam vacuum tube, invented in 1937 by american electrical engineers russell and sigurd varian, which is used as an amplifier for high radio frequencies, from uhf up into the microwave range.
Microwave engineering reflex klystron tutorialspoint. Pdf experimental study of complex dynamics in a delayed. Oct 03, 2016 two cavity klystron amplifier s working. In a klystron amplifier the input cavity is called. Reflex klystron amplifier electronics club microwave. Positive feedback excites spontaneous oscillations at the resonant frequency of the cavities.
Twocavity klystron amplifier 62801 circuit and wiring. Microwave engineering cavity klystron for the generation and amplification of microwaves, there is a need of some special tubes called as microwave tubes. The application for klystron with integral cavities is usually credited in the early 1939 to hahn and metcalf and to russell and sigurd varian, two brothers that. A klystron tube makes use of speedcontrolled streams of electrons that pass through a resonating cavity. Klystron is the simplest vacuum tube that can be used for amplification or generation of microwave signal. To attain this result, the field in the output cavity of a klystron is detected by a probe. Development of a 500 mw, onemicrosecond, multikiloampere. The power gain of a two cavity klystron amplifier is about 30 db. The dimensions of the resonant cavities of the multiplebeam klystron are determined in such a way as to enable functioning in the tm 0n mode na whole number greater than 1 and drift tubes relative to the beams go through the klystron cavities at places where the electrical field, in the cavities, is at its maximum value. Modified image based on a drawing by christian wolffcc bysa 3. The location is determined by the transit time of the bunches at the. Klystron tube article about klystron tube by the free.
The two cavity klystron in figure 2 7 may be used either as an oscillator or an amplifier. Multicavity klystron two cavity klystron amplifier. A klystron is provided for supplying power with optimum efficiency across a variable impedance load. Functional and schematic diagram of a twocavity klystron. Principle high velocity electron beam is formed, focused and sent down along a glass tube to a collector electrode, which is at a high positive. The klystron was invented at stanford university in 1937 and originally used as the oscillator in radar receivers during world war ii. This microwave generator, is a klystron that works on reflections and oscillations in a single cavity, which has a variable frequency.
So far, weve taken b 1 in treating beamcavity interaction, which allows for the approximation of the beam as an ideal current source i. A fourway tm010 mode cavity power combiner achieved a transmis sion loss of less than 0. Klystrons are typically designed to operate at a single fixed frequency. A multi cavity klystron amplifier according to claim 1 wherein said output cavity comprises an electroconductive cylinder, electroconductive end plates connected to the opposite ends of said cylinder and provided with axial openings for passing said electron beam, drift tubes secured to the inner sides of said end plates, tuning means electrically connected to one side wall of said cylinder. It is known by this name due to its reflex action of electron beam. Klystron was developed by russell h varian at stanford university in 1939, in association with his brother sp varian. It also utilizes a collector element at the end of the electron stream. The reflex klystron is mostly used as a microwave oscillator.
Multistage depressed collector klystron allows the amplifier to use less power and produce less heat than other khpas. The signal supplied by the probe is used for adjusting the amplitude of the ultrahigh frequency voltage applied to. Two cavity klystron free study notes for mba mca bba. The separation between buncher grids and catcher grids is called. Would you like to make it the primary and merge this question into it. The rf source is a klystron amplifier see section 17. Electrons in a klystron are accelerated to a controlled speed by the application of several hundred volts. The reflex klystron contains a reflector plate, referred to as the repeller, instead of the output cavity used in other types of klystrons. Complex dynamics of a doublecavity delayed feedback klystron. Although a small deviation has been found in tuning. What is a klystron amplifier, types, differences and their. Bb4c6c from alamys library of millions of high resolution stock photos, illustrations and vectors. Important question and answers on reflex klystron with. For a lower price and with a reduced warranty a rebuild of our tube, product number l582290, is also available.
This document consists of basic marketing information that is not defined as technical data under ear part 772. As shown electron beam is generated by electron gun which passes through the space. A collection of theoretical analyses is presented for rf cavities, intense electron beams, beam cavity interactions, and smallsignal klystron bunching. As for ec, the development issues for the klystron relate mainly to the cooling of the structure. It provided much higher powers than had previously been obtainable at these frequencies. The velocities of electrons emitted from the cathode are modulated to produce a densitymodulated electron beam. Now understand the concept of reflex klystron in microwave engineering in details through following questions and answers. Content introduction of two cavity klystron construction of two cavity klystron two cavity klystron amplifier performance characteristics application 3. The r f power from the drive amplifier system is split 2 and distributed to n amplifier modules 1 the outputs of which are recombined 3 and coupled to the rf waveguide feeder. F output from the cavity with the help of loop coupling. In this tube there are two microwave cavity resonators, the catcher and the buncher.
The multicavity klystron was invented just before world war ii by the varian brothers as a source and amplifier of microwaves. These will set up a field in the third cavity, which produces more concentrated bunches and. A 2 cavity klystron amplifier comprises of a cathode focusing, electrodes, two buncher grids divided by a extremely small space appearing a gap a, two catcher network with a small gap b trail by a collector. The term klystron is taken from the stem form of a greek verb klys referring to the flow of waves breaking next to a shore, as well as the last part of the term electron. Specifications for klystron high power amplifier khpa general description. In order to achieve higher overall gain, one way is to connect several twocavity tubes in cascade, feeding the output to each of. The frequency can be slightly adjusted by mechanically deforming the resonant cavities. Reflex klystron amplifier, microwave klystron amplifier 1. In the next post we will see the variant of two cavity klystron called reflex klystron posted by unknown at 09. Design and construction of a cavitytype combiner is described to be used in combining output power of pulsed transistor amplifier modules at s band.
Gen iv klystron high power amplifier cband highly efficient provides up to 2. It has two microwave cavity resonators the catcher and the buncher. Twocavity klystron amplifier in the twochamber klystron, the electron beam is. F input signal to the buncher cavity with the help of loop coupling.
The operation of klystron depends upon velocity modulation which leads to density modulation. Connect the detector output to y input and sawtooth output of the klystron of power supply to xinput of scope fig. The physical motivation of the proposal consists in the effect of lengthy bunch rearrangement due to the interaction with the highstrength rf fields. Xband klystron amplifier for use in high energy linear accelerator systems.