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. The electrons are fired into one end of the tube by an electron gun. Microwave tubes as microwave source oscillators and amplifiers. Additional cavities serve to velocitymodulate the electron beam and produce an increase in the energy available at the output. Connect the heater and cathode leads of the klystron to each other. In a reflex klystron, a small modulation of the repeller voltage is more often employed to fix the emitted frequency to that of a microwave resonator by a phase locking loop technique. I was an aetm3c in the navy and also remember those local oscillators. Lowpower klystrons are used as oscillators in terrestrial microwave relay. Western electric 707a reflex klystron klystron reflex.
Reflex klystron pdf would have, spotydl download for mac, last man standing killbook of a bounty hunter pdf. 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. Since there is no reflector, only one highvoltage supply is required. Reflex klystron used as a lowpower microwave oscillator 2. Yes, they had a bellows that was externally adjusted to cause the separation between grids that coupled to a resonant chamber as reflex. Different characteristics of reflex klystron can be determined using the whole associated package for reflex klystron experiments. Klystron multi cavity klystron, reflex klystron, working. Important question and answers on reflex klystron with. But 2cavity klystron oscillator is not used because the slight change in. Cavity of a repeller klystron another tube based on velocity modulation, and used to generate microwave energy, is the reflex klystron repeller klystron. The main applications of a reflex klystron are as follows1. Feb 18, 2018 reflex klystron is one of the most commonly used microwave low power generators.
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. It is possible to produce oscillations in a klystron device which has only one cavity, through which electrons pass twice. Klystron power supply, klystron tube, isolator, frequency meter, variable attenuator, detector mount, waveguide stand, vswr meter and bnc cable. This type of a klystron is called a reflex klystron because of the reflex action of the electron beam.
Consequently, more than two cavities are always employed in practical klystron amplifiers. The reflex klystron makes use of velocity modulation to transform a continuous electron beam into. When the beam of electrons reflect back to the grid due to the repeller voltage in reflector plate,how the grid decelerates the returning electrons and how they release their energy to the grid. Klystron article about klystron by the free dictionary. Aug 16, 2006 the twocavity oscillator klystron normally generates more power than the reflex klystrontypically watts of output rather than milliwatts. Us3060342a us845194a us84519459a us3060342a us 3060342 a us3060342 a us 3060342a us 845194 a us845194 a us 845194a us 84519459 a us84519459 a us 84519459a us 3060342 a us3060342 a us 3060342a authority us united states prior art keywords portion wall movable wall cavity resonator reflex klystron prior art date 19581120 legal status the legal. Reflex klystrons were developed in 1940 by the soviet engineers n. Here we will study the construction, operation, application and performance parameter of reflex klystron.
The basic electrode arrangement of a reflex klystron is given below. 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 electron beam attains a high velocity due to the accelerating anode. Multi cavity klystron two cavity klystron used as lowpower.
The twocavity klystron utilizes an electron source heater, an anode, and a cathode like a conventional. The reflex klystron another tube based on velocity modulation, and used to generate microwave energy, is the reflex klystron figure 29. The expected lifetime of a tetrode in uhf service is usually shorter than a klystron ofthesamepowerlevel. View and download powerpoint presentations on reflex klystron ppt. Klystron for high gradient accelerator research, in aip conf. In the work been done the design and simulation of 2. Together, the magnetron and the klystron made possible airborne sband radar, a major factor in securing air superiority for the raf. 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. 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. Another tube based on velocity modulation, and used to generate microwave energy, is the reflex klystron figure 29. The electron gun emits the electron beam, which passes through the gap in the anode cavity. Multi cavity klystron used as lowpower microwave amplifier reflex klystron reflex klystron reflex klystron single reentrant cavity as a resonator.
These electrons move at a uniform speed towards the anode until they are attracted by it. Reflex klystron vacuum tube manufactured goods free 30. Multicavity klystron two cavity klystron amplifier. F input signal to the buncher cavity with the help of loop coupling. Reflex klystron article about reflex klystron by the. This single cavity is work like a buncher as well as catcher cavity. Contents introduction construction working reflex klystron oscillator applications 3. Typicallifetimesof8,000to15,000hourshavebeenreported. Reflex klystron amplifier, microwave klystron amplifier 1. It is given the name reflex klystron because of its reflex action of electron beam.
The reflex klystron contains a reflector plate, referred to as the repeller, instead of the output cavity used in other types of klystrons. Rigid design shear strength precisely engineered experiments. Difference between two cavity klystron and reflex klystron. Why is pulse modulation required in reflex klystron. The schematic diagram of a reflex klystron tube is shown in fig. Used as the local oscillator in the so and anapn7 radars and in the navy lag signal generator.
Klystron, thermionic electron tube that generates or amplifies microwaves by controlling the speed of a stream of electrons. Microwave engineering kg reddy college of engineering. The bunches of electrons excite microwaves in the output cavity of the klystron. When there is no signal voltage on the pair of sockets 6, then, with button 2. Reflex klystron or repeller klystron another tube based on velocity modulation, and used to generate microwave energy, is the reflex klystron repeller klystron. As shown electron beam is generated by electron gun which passes through the space between input cavity i. A klystron is a vacuum tube that can be used either as a generator or as an amplifier of power, at microwave frequencies. Reflex klystron oscillator pdf source of an electronbeam and the radiofrequency por tion of the klystron is independent of the electron source. Oct 01, 2014 336 microwave linearbeam tubes 0 type table 901 linear beam tubes 0 type cavity \ resonant reflex klystron twystron linearbeam tubes 0type i slowwave structure forwardwave coupledcavity twt i backwardwave chap. Microwave engineering reflex klystron tutorialspoint. Reflex klystron article about reflex klystron by the free. Reflex klystron calculator converters and calculators. Mar 24, 2016 working of reflex klystron oscillator.
Request pdf frequency control of a klystrontype relativistic cerenkov. The reflex klystron oscillator is a lowpower, lowefficiency microwave oscillator, illustrated schematically in figure 118. Reflex klystron amplifier, microwave klystron amplifier. Define reflex klystrons, some characteristics and applications.
It is known by this name due to its reflex action of electron beam. Reflex klystrons are well adapted as frequency modulated. The analysis is similar to earlier explanations of electron bunching in a fieldfree drift space and predicts a similar current distribution when bunching takes. Since all intermediate cavities in a multicavity klystron operate in the. Buncher cavity is the input cavity at which the electrons are bunched and the catcher cavity is the output cavity at which the output is taken but in reflex klystron only one cavity is present where the bunching process as well as output taken. Principles of twocavity klystrons twocavity klystron geometry. Description this integrated industrial microwave power system uses a cpi vks7960a klystron, designed for industrial service, as the energy source.
This is the reflex klystron oscillator, which will now be described. For this article, however, we will focus on another popular type. Oscillators,in this video we will learn generation of microwave frequencies using reflex klystron oscillator. The reflex version of the klystron, perfected at sperry and in british laboratories, served as the local oscillator in superheterodyne radar receivers. These reflex klystrons continued to occupy a significant position in the testing world, and by the mid80s, reflex klystrons were available up into the 100s of gigahertz. Frequency control of a klystrontype relativistic cerenkov. Klystron oscillator reflex klystron traveling wave tube magnetron. A reflex klystron is an obsolete type in which the electron beam was reflected back along its path by a high potential electrode.
Klystron types there are two basic configurations of klystron tubes 1. One major type is the reflex klystron, which is used primarily as an oscillator. In industrial applications, solid state devices have completely replaced the. Microwave engineering cavity klystron tutorialspoint. First of all, consider an electron a which passes through the resonator. Microwave engineering cavity klystron for the generation and amplification of microwaves, there is a need of some special tubes called as microwave tubes. Klystron works on the principle of velocity modulation of electrons. In the reflex klystron, the electron beam passes through a single resonant cavity. The first papers on the theory of the reflex klystron were published by the soviet physicists ia. Of the resulting frequency spectrum only a narrow band, which. The main difference between two cavity reflex klystron amplifier. Consult cpi to obtain the required connector if you are working with an msdc klystron.
The power output is high in the first mode of operation of the reflex klystron. The microwaves flow into the waveguide, which transports them to the. For proper working as an oscillator the output voltage needs to be fed back to the input and if positive feedback is taken then only the klystron will oscillate. Frequency extension source modules to extend signal generator capability from 50 to 325 ghz. Reflex klystron oscillator operation application of. Reflex klystron amplifier electronics club microwave. What is the difference between the two cavity klystron. The passthrough effect, therefore, contributes to the overall operating efficiency of the transmitter. The bunching cavities regulate the speed of the electrons so that they arrive in bunches at the output 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. A klystron is a vacuum tube that can be used either as a generator or as an amplifier of power, at microwave frequencies klystron types there are two basic configurations of klystron tubes 1. This beam then passes through the drift space having length l and finally through the catcher cavitythe name is referred as catcher since the output is obtained at this. Other articles where twocavity klystron is discussed.
Another tube based on velocity modulation, and used to generate microwave energy, is the reflex klystron. 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. The reflex version of the klystron, perfected at sperry and in british. Following is the list of useful converters and calculators. 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. The operating frequency, between 1150 and 3750 mhz, was determined by an external clampon mcnally cavity. How reflex klystron works electrical engineering stack exchange. The electron beam is created with the help of the cathode.
Operation is similar to that of a klystronexcept that coupledcavity twts are designed with attenuation between the slowwave structure instead of a drift tube. 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. Now understand the concept of reflex klystron in microwave engineering in details through following questions and answers. Following equation or formula is used for reflex klystron calculator. A comprehensive analysis of reflex klystrons is developed by considering the electrons as particles acted upon by forces which modify their motion. In order to generate microwave frequencies we need amplifiers or oscillators,in this video we will learn how a reflex klystron oscillator works in generation of microwave frequencies. Would you like to make it the primary and merge this question into it. Reflex klystron is one of the most commonly used microwave low power generators. The electron beam emitted from the cathode is accelerated by the grid and passes through the cavity anode to the repeller space between. It is used to combine the powers or to separate the power of various sources. Electrons emitted from the cathode are accelerated and passed through the positive resonator towards negative reflector, which retards and finally reflects the electrons towards the resonator. 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.
In this klystron, a single pair of grids does the functions of both the buncher and the catcher grids. Find powerpoint presentations and slides using the power of, find free presentations research about reflex klystron ppt. The reflex klystron makes use of velocity modulation to transform a continuous electron beam into microwave power. Reflex klystron is also known as a sutton klystron. Normally we use separate components in devices such as radio transmitters and receivers but as frequencies increase the two components merge into one structure and become a. The reflex klystron operates in a different mode for each additional cycle that the electrons remain in the repeller field.
To study the characteristics of reflex klystron the reflex klystron utilizes velocity modulation to convert regular electron beam energy into microwave power. So basically what was the need for reflex klystron when we had multicavity klystron. Mode 1 is obtained when the repeller voltage produces an electron transit time of 34 cycle. 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. The reflex klystron is an oscillator with a built in feedback mechanism. The name klystron comes from the greek verb klyzo referring to the action of waves breaking against a shore, and the suffix. After passing through the resonant cavity they are reflected by a negatively charged reflector electrode for another pass through the cavity, where they are then collected. Reflex klystron free download as powerpoint presentation.
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