My apologies for the long answer but this is a complicated bit of technology and needs an appreciation of the physics behind it. Slow wave structures are also otype but have nonresonant periodic structures for electron interactions. A microwave source of surprising range and endurance. Microwave engineering cavity klystron for the generation and amplification of microwaves, there is a need of some special tubes called as microwave tubes. Jul 31, 2018 technical article introduction to the twocavity 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. The constructional details of this reflex klystron is as shown in the following figure. To understand the operation of a reflex klystron i think you need to start with a basic understanding of a tuned circuit made up from a capacitor c and inductor l. So, this is how oscillations are sustained in the reflex klystron by to and fro movement of electrons from cavity to repeller space. Klystron vs magnetrondifference between klystron,magnetron.
A klystron is a vacuum tube that can be used either as a generator or as an amplifier of power, at microwave frequencies. Microwave engineering cavity klystron tutorialspoint. Following is the list of useful converters and calculators. As shown in the given diagram it is composed of heater, cathode, focusing electrodes and repeller anode. Klystrons make use of the transittime effect by varying the velocity of an. Important question and answers on reflex klystron with. This type of klystron oscillator is called a reflex klystron because of the reflex action of the electron beam. Introduction to the twocavity klystron amplifier technical. On this channel you can get education and knowledge for general issues and topics. This microwave generator, is a klystron that works on reflections and oscillations in a single cavity, which has a variable frequency.
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. Find powerpoint presentations and slides using the power of, find free. The general construction of the reflex klystron oscillator and a two. In general, the condition for optimum operation of a reflex klystron is the same as for the tworesonator klystron, namely, the center of the bunches in the stream should pass through the catcher when the catcher field has its greatest retarding effect. Pdf optimization of micromachined reflex klystrons for. The sylvania type 6bm6 is a broadband reflex klystron designed for cw operation. The electrons while passing through the anode cavity, gain some velocity. Reflex klystron is also known as a sutton klystron. Explain the operation mechanism of two cavity klystron amplifier with neat sketch. The reflex klystron oscillator is a lowpower, lowefficiency microwave oscillator, illustrated schematically in figure 118. All these components are enclosed in a glass envelope.
The difference between reflex and twomulti cavity klystron is that, reflex klystron uses single cavity for modulationdemodulation. The main difference between two cavity reflex klystron amplifier. Connect the components and equipments as shown in the fig. The operation of reflex klystron is understood by some assumptions. Reflex klystron article about reflex klystron by the free. Klystron multi cavity klystron, reflex klystron, working. A comprehensive analysis of reflex klystrons is developed by considering the electrons as particles acted upon by forces which modify their motion. The name of this klystron is taken due to its reflex act of electron beam. What are the assumptions for calculation of rf power in reflex klystron. The reflex klystron contains a reflector plate, referred to as the repeller, instead of the output cavity used in other types of klystrons. Which is impossible and not feasible to use other components for this purpose.
Reflex klystron consists of an electron gun, a cathode filament, an anode cavity, and an electrode at the cathode potential. Reflex klystron used as a lowpower microwave oscillator 2. Multicavity klystron two cavity klystron amplifier. The analysis is similar to earlier explanations of electron bunching in a fieldfree drift space and predicts a similar current distribution when bunching takes. Reflex klystron amplifier electronics club microwave. Set the variable attenuator at the maximum position a zero micrometer reading. Klystron power supply, klystron tube, isolator, frequency meter, variable attenuator, detector mount, waveguide stand, vswr meter and bnc cable. To understand the operation of a reflex klystron i think you need to start with a basic understanding of a tuned circuit made up from a capacitor. Different characteristics of reflex klystron can be determined using the whole associated package for reflex klystron experiments. So, electron beam is injected from the cathode and that injected beam travel with a.
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. This single cavity is work like a buncher as well as catcher cavity. Microwave engineering reflex klystron tutorialspoint. Set the variable attenuator to maximum and klystron cathode power supply to. To study the characteristics of the reflex klystron tube and to determine its electronic tuning range.
Reflex klystron article about reflex klystron by the. It is assumed that oscillations already exist in the tube and they are sustained by its operation. Reflex klystron telecommunications engineering mechanics. The bunching process in a twocavity klystron is by no means complete, since there are large numbers of outofphase electrons arriving at the catcher cavity between bunches. Twystron is a hybrid amplifier which uses a combination of klystron and slow wave structures. Of the resulting frequency spectrum only a narrow band, which. Jensen abstract this report deals with a method of modulating a reflex klystron whereby the message to be transmitted is modulated on a subcarrier, which in turn modulates the klystron through its repeller. This is the reflex klystron oscillator, which will now be described. A singlecavity klystron in which the electron beam is reflected back through the cavity resonator by a repelling electrode having a negative voltage. The electron beam is modulated as it was in the other types of klystrons by passing it through an oscillating resonant cavity, but here the similarity ends. The ranges of all these voltages are given in the specification data sheet. In klystron strong electrostatic fields are required for its operation efficiently.
Here we will study the construction, operation, application and performance parameter of reflex klystron. So, working principle of reflex klystron is velocity and current modulation. The reflex klystron another tube based on velocity modulation, and used to generate microwave energy, is the reflex klystron figure 29. The losses due to circuit factors can be reduced by a judicious use of the microwave. Optimization of micromachined reflex klystrons for operation. The electron beam is accelerated towards the anode cavity. Study of the characteristics of the klystron tube objective. Pure carrier wave operation and in external modulation facilities is also provided with the instrument for generalized use. View and download powerpoint presentations on reflex klystron ppt. Now, let us see bunching process and the modes and reflex klystron, this vertical axis. This time, however, the reference electron is taken as one that passes the gap on its way to the repeller at the time when the gap voltage is zero and going negative.
Pdf optimization of micromachined reflex klystrons for operation. Moreover it uses repeller inplace of catcher cavity. Reflex klystron oscillator operation application of. Klystron tube 2k25 the klystron tube 2k25 is a single cavity variable frequency microwave generator of low. Following equation or formula is used for reflex klystron calculator. Klystron amplifier klystron amplifiers are high power microwave.
The electronic tuning range of the reflex klystron is usually referred to as the variation in frequency between half power pointsthe points in the oscillating mode where the power output is half the maximum output in the mode. Request pdf parametric analysis of micromachined reflex klystrons for operation at millimeter and submillimeter wavelengths a tool for the simulation of high frequency reflex klystrons is. Pdf new micromachining techniques now provide us with the technology to fabricate reflex klystron oscillators with dimensions suitable for operation. The cavity resonator must be flexible on at least one wall due to the tolerances of the tube manufacturer. This klystron is totally dissimilar from cavity klystron because it has a single cavity and used for modulation otherwise demodulation. Study of the characteristics of the klystron tube objective to study the characteristics of the reflex klystron tube and to determine the its electronic tuning range equipments klystron power supply, klystron with mount, isolator, frequency meter, variable attenuator, xband detector, bnctobnc cable and oscilloscope theory. Multi cavity klystron two cavity klystronused as lowpower microwave amplifier two. A microwave source of surprising range and endurance george caryotakis stanford linear accelerator center, stanford university, stanford ca 94309 abstract this year marks the 60th anniversary of the birth of the klystron at stanford university. The reflex klystron utilizes velocity modulation to convert regular electron beam energy into microwave power. First of all, consider an electron a which passes through the resonator gap when the voltage across the gap is zero.
Now understand the concept of reflex klystron in microwave engineering in details through following questions and answers. After the focusing electrodes there is a cavity resonator which encircles the glass envelope. Additional cavities serve to velocitymodulate the electron beam and produce an increase in the energy available. Experiment4 study of the characteristics of the klystron tube. A klystron is basically a vacuum tube with input and output structures replaced with resonant cavities known as buncher cavity and catcher cavity. And the another difference is that in twocavity klystron at this place there is a collector which is used to collect the electron beam coming from the output cavity. Another tube based on velocity modulation, and used to generate microwave energy, is the reflex klystron figure 29. A reflex klystron is an obsolete type in which the electron beam was reflected back along its path by a high potential electrode, used as an oscillator. To study the characteristics of reflex klystron labappara. It is possible to produce oscillations in a klystron device which has only one cavity, through which electrons pass twice. Reflex klystron is one of the most commonly used microwave low power generators. Reflex klystron amplifier, microwave klystron amplifier. Three power sources are required for reflex klystron operation.
The schematic diagram of a reflex klystron tube is shown in fig. The name klystron comes from the greek verb klyzo referring to the action of waves breaking against a shore, and the suffix. Contents introduction construction working reflex klystron oscillator applications 3. Multi cavity klystron two cavity klystron used as lowpower microwave amplifier two. This page on klystron vs magnetron describes difference between klystron and magnetron. Consequently, more than two cavities are always employed in. Electron emitted from the cathode are accelerated and passed through the positive. It covers basics of klystron and magnetron and mention difference between them. So, this is how electrons move in this reflex klystron tube.
It was used as a local oscillator in some radar receivers and a modulator in microwave transmitters the 1950s and 1960s, but is now obsolete, replaced by semiconductor microwave devices. 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 reflex klystron makes use of velocity modulation to transform a continuous electron beam into. Ppt and pdf similar books klystron theory klystron diagram klystron download download reflex klystron operation pdf read online read online reflex klystron operation pdf. The reflex klystron also known as a sutton tube after one of its inventors, robert sutton was a low power klystron tube with a single cavity, which functioned as an oscillator. Reflex klystron microwave tubes klystron, reflex klystron, magnetron and twt reflex klystron is single cavity variable frequency microwave oscillator. The operation of reflex klystron is a little bit different from the twocavity klystron because there is only one cavity. Parametric analysis of micromachined reflex klystrons for. Optimization of micromachined reflex klystrons for operation at terahertz frequencies article pdf available in ieee transactions on microwave theory and techniques 5210. The reflex klystron contains a reflector plate, referred to as the. Modern semiconductor technology has effectively replaced the reflex klystron in most applications.
Operation the klystron was the first embodiment of the velocity modulation principle. In this klystron, a single pair of grids does the functions of both the buncher and the catcher. Pdf a476, reflex klystron klystron application of reflex klystron klystron reflex klystron pin connection klystrons reflex klystron reflex klystron s band cavity resonator. As with the multicavity klystron, the operating mechanism is best understood by considering the behavior of individual electrons. In addition, note that the power output for the various modes. Each reflex klystron, therefore, has its own calibration protocol. What is a klystron amplifier, types, differences and their. Klystron types there are two basic configurations of klystron tubes 1. Nov 09, 2016 on this channel you can get education and knowledge for general issues and topics. 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. In this klystron, a single pair of grids does the functions of both the buncher and the catcher grids. Klystron works on the principle of velocity modulation of electrons. Reflex klystron calculator converters and calculators.
There are no two identical reflex klystrons, even if. Ph0101 unit 2 lecture 6 2 reflex klystrons the reflex klystron has been the most used. There are no two identical reflex klystrons, even if they are manufactured in the same series. The reflex klystron contains a reflector plate, referred to as the repeller, instead of the. The reflex version of the klystron, perfected at sperry and. The klystron power supply also provides all the other d. The reflex klystron makes use of velocity modulation to transform a continuous electron beam into microwave power.
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