Klystron and microwave department capabilities and xband. Klystron, thermionic electron tube that generates or amplifies microwaves by controlling the speed of a stream of electrons. Pdf circuit analysis of kaband extended interaction klystron. 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 report deals with a method of modulating a reflex klystron whereby the. Lowpower klystrons are used as oscillators in terrestrial microwave relay communications links, while highpower klystrons are used as output tubes in uhf television. It is of the same rugqedized construction as the bendix 6116tk62 the tube is, division, eatontown, new jersey publication no. Klystron types presentday klystrons fall into three categories. Reflex klystron free download as powerpoint presentation. Klystron power supply, klystron tube, isolator, frequency meter, variable attenuator, detector mount, waveguide stand, vswr meter and bnc cable. It has two microwave cavity resonators the catcher and the buncher. In fact, according to kek injector operating statistics during 10 years in 2000s, the failures in focusing solenoids were the most frequent reasons to exchange klystron assemblies among the other.
This type of klystron oscillator is called a reflex klystron because of the reflex action of. Reflex klystron vacuum tube manufactured goods free. State the characteristics of the twocavity klystron amplifier. These questions are likely to appear in the examination but if these questions doesnt appear in exam then m group doesnt take any resposibility. Reflex klystron working, oscillator and applegate diagram. First, you need to determine what your need for a klystron is. It is given the name reflex klystron because of its reflex action of electron beam. At microwave frequencies, however, the transit time or angle is large compared to the period of the microwave.
Microwave engineering ece questions and answers page 6. The stabilizing system has a holding range of several megacycles which permits the sweeping of the reference crystal oscillator. Lowpower klystrons are used as oscillators in terrestrial microwave relay. We suppose the negative half cycle of the input signal. Controls the entire 2 mw klystron transmitter is controlled and monitored figure 6 through a threelevel system, similar to other dti transmitter control system designs. 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. Twystron is a hybrid amplifier which uses a combination of klystron and slow wave structures.
Performance evaluation of klystron beam focusingsystem with. Modulation characteristics a considerable amount of information about this system can be gained by studying the effect of slowly varying the subcarrier amplitude. The main difference between two cavity reflex klystron amplifier. The electron gun emits the electron beam, which passes through the gap in the anode cavity. A klystron looks and works something like an organ pipe. 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. Microwave engineering ece questions and answers this is the electronics and communication engineering questions and answers section on microwave communication with explanation for various interview, competitive examination and entrance test. A klystron is a specialized linearbeam vacuum tube, invented in 1937 by american electrical. Reflex klystron used as a lowpower microwave oscillator 2. 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. What links here related changes upload file special pages permanent link. Oct 01, 2014 340 microwave linearbeam tubes 0 type chap. Reflex klystron consists of an electron gun, a cathode filament, an anode cavity, and an electrode at the cathode potential. The brothers russell and sigurd varian of stanford university are the.
A klystron is a vacuum tube that can be used either as a generator or as an amplifier of power, at microwave frequencies. Klystron oscillator reflex klystron traveling wave tube magnetron klystron. The essential elements of klystron are electron beams and cavity resonators. A klystron tube makes use of speedcontrolled streams of electrons that pass through a resonating cavity. The klystron was invented at stanford university in 1937 and originally used as the oscillator in radar receivers during world war ii. Klystron is a microwave generator compare slacs large, highpower microwave generator klystron below with this much smaller one magnetron right from a typical microwave oven. Klystron usually will have two or more cavities as per gain and bandwidth requirements needed for different applications. Modelbased klystron linearization in the swissfel test.
From each mode and the band of frequencies over which the circuit can be tuned. The tube provides 5 kw cw output power at 1497 mhz and is permanentmagnet focused with a four. Electrons in a klystron are accelerated to a controlled speed by the application of several hundred volts. Klystron oscillator reflex klystron traveling wave tube magnetron. All these components are enclosed in a glass envelope. The paramount o type tube is the two cavity klystron followed by the reflex klystron. Difference between two cavity klystron and reflex klystron.
Experiment4 study of the characteristics of the klystron tube. Sep 27, 2017 in this video, i have explained reflex klystron with following points 1. This paper describes a new deq circuit with feedforward compensation to stabilize the output pulse amplitude of the existing modulator for the pulse klystron. Multiple beam klystron research at calabazas creek research. Klystron for high gradient accelerator research, in aip conf. 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.
Circuit analysis of kaband extended interaction klystron. The average lifetime of a klystron tube is 24,216 h and that of a thyratron is 14,991 h below 1,000h infant failure is excluded in the statistics. Klystron production is now proceeding at tubes per month. May 31, 2014 a microwave bench setup for study of klystron modes observations. Microwave engineering reflex klystron tutorialspoint. Klystron types there are two basic configurations of klystron tubes 1. For the generation and amplification of microwaves, there is a need of some special tubes called as microwave tubes. Ccr is developing multiple beam klystrons for two accelerator applications. Klystron vs magnetrondifference between klystron,magnetron. After the electron gun there are two focusing electrodes used to keep the electron beam in the center around the glass envelope. The general approaches, which are being studied intensively, are. A klystron is basically a vacuum tube with input and output structures replaced with resonant cavities known as buncher cavity and catcher cavity. Figure 1 illustrates the data of a klystron in the swissfel test facility and the tted model from 1.
Reflex klystron vacuum tube manufactured goods free 30. Cavity of a repeller klystron another tube based on velocity modulation, and used to generate microwave energy, is the reflex klystron repeller klystron. Of the resulting frequency spectrum only a narrow band, which. Klystron multi cavity klystron, reflex klystron, working. For the purpose of this discussion the klystron is considered as a two terminalpair. Question bank department of electronics and communication.
When switch on the circuit, the electrons starts emitting from the cathode. Multi cavity klystron two cavity klystronused as lowpower. Klystron article about klystron by the free dictionary. This microwave generator, is a klystron that works on reflections and oscillations in a single cavity, which has a variable frequency. Performance evaluation of klystron beam focusingsystem. The simplest klystron tube is the twocavity klystron. A twocavity klystron amplifier has the following parameters. It covers basics of klystron and magnetron and mention difference between them. The beam voltage is set in the range of 0205v after this voltage the device will be spoilt and cannot be used further. Slow wave structures are also otype but have nonresonant periodic structures for electron interactions. Reflex klystron thermally tuned description the bendixa type tk68 tube is a thermally tuned c band reflex oscillator. The efficiency of klystron results from the ratio of the power. A read is counted each time someone views a publication summary such as the title, abstract, and list of authors, clicks on a figure, or views or downloads the fulltext. Klystron an ultrahighfrequency electronic vacuum device in which a steady stream.
As shown in the given diagram it is composed of heater, cathode, focusing electrodes and repeller anode. The schematic diagram of a reflex klystron tube is shown in fig. Microwave engineering cavity klystron tutorialspoint. If you need an oscillator, a reflex tube will work fine, but it is old school technology. Circuit analysis of kaband extended interaction klystron conference paper pdf available in journal korean physical society 445. 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. Another tube based on velocity modulation, and used to generate microwave energy, is the reflex klystron figure 29. This page on klystron vs magnetron describes difference between klystron and magnetron. A klystron is a specialized linearbeam vacuum tube evacuated electron tube the name klystron comes from the stem form. Microwave engineering cavity klystron for the generation and amplification of microwaves, there is a need of some special tubes called as microwave tubes.
An eight beam, 50 mw multiple beam klystron is currently being assembled with an eight beam electron gun built and successfully tested on a previous program. How are oscillations produced in a reflex klystron. Performance characteristics of the cebaf klystron amplifier. In this klystron, a single pair of grids does the functions of both the buncher and the catcher grids. A reflex klystron achieves the same bunching by causing the beam to reverse. This change has a direct effect on the design of the klystron modulator. A microwave source of surprising range and endurance pdf. The klystron was the first embodiment of the velocity modulation principle. The klystron beam focusing system is one of the key components in the whole system. In order to reduce the energy jitter pulsetopulse, a stabilization of the klystron modulator output is essential. What are the performance characteristics of klystron amplifier. Microwave engineering reflex klystron this microwave generator, is a klystron that works on reflections and oscillations in a single cavity, which has a.
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. After the focusing electrodes there is a cavity resonator which encircles the glass envelope. Modelbased klystron linearization in the swissfel test facility. In this video, i have explained reflex klystron with following points 1. The first level, fast control and monitoring, provides fast response, hardwired fault detection, and safety shutdown. Klystronmodulator system performance for the advanced. The reflex klystron contains a reflector plate, referred to as the repeller, instead of the output cavity used in other types of klystrons. A microwave bench setup for study of klystron modes observations. 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. These electrons move at a uniform speed towards the anode until they are attracted by it. Give the range for beam voltage for reflex klystron power supply ans. F input signal to the buncher cavity with the help of loop coupling.
Sketch output power and frequency of klystron versus repeller voltage for reflex klystron. Draw the schematic diagram of helix travelling wave tube. Derive an expression for the efficiency of the klystron amplifier. At microwave frequencies, however, the transit time or angle is large compared to the period of the microwave signal, and the potential between the cathode and the. The multi cavity klystron consist of a glass envelope in which there is an electron gun composed of heater and cathode. The reflex klystron makes use of velocity modulation to transform a continuous electron beam into. The modulator is the dc power supply for the klystron. This model describes the saturation and oversaturation characteristics of a klystron for constant high voltage. In this tube there are two microwave cavity resonators, the catcher and the buncher. Klystron rf stabilization using feedforward circuit.
1297 1055 32 756 521 380 393 1383 698 1214 1537 1328 360 865 597 120 230 947 203 562 977 1092 611 1527 424 1474 1558 1384 351 322 506 43 187 1478 1279 609 893 1324 764 1421 1373 1235 979 259 307 497 1282