This is the reflex klystron oscillator, which will now be described. The eik integrates a 3cavity circuit with our previously demonstrated 20kv, 3. Microwave engineering example problems tutorialspoint. In the last lecture, we discussed conventional tubes and their high frequency. In the reflex klystron the electron beam passes through a single resonant cavity. As shown electron beam is generated by electron gun which passes through the space between input cavity i. All the electrons injected from the cathode arrive at the first cavity with uniform velocity. Pdf study of a reflex klystron emmanuel markoulakis. In addition to the twt competition, lowpower klystrons, particularly reflex oscillators,7 lost the battle to solidstate replacements in radar and communication.
Wband sheet beam klystron pcm focusing design request pdf. In this klystron, a single pair of grids does the functions of both the buncher and the catcher grids. Cavity grids and repeller are plane parallel and very large in extent. Important question and answers on reflex klystron with. 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. Different characteristics of reflex klystron can be determined using the whole associated package for reflex klystron experiments. Reflex klystron article about reflex klystron by the. A klystron is a specialized linearbeam vacuum tube, invented in 1937 by american electrical.
A singlecavity klystron in which the electron beam is reflected back through the cavity resonator by a repelling electrode having a negative voltage. A wband sheetbeam extended interaction klystron eik has been fabricated and tested. The main difference between two cavity reflex klystron. Reflex klystron oscillator pdf source of an electronbeam and the radiofrequency por tion of the klystron is independent of the electron source. The first prototype, wsbk1a, is a 95 ghz wband device with a 74 kv, 3. 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 reflex klystron tutorialspoint. Reflex klystron working, oscillator and applegate diagram. Various fundamental principle are used for the analysis and design purpose with the application of field measurement techniques. Difference between two cavity klystron and reflex klystron. In this klystron, a single pair of grids does the functions of both the buncher and the catcher. Dig schematic diagram of two cavity reflex klystron oscillator mechanism of operation 1.
Operation klystrons amplify rf impinj speedway revolution. The electrons are fired into one end of the tube by an electron gun. Reflex klystron oscillator operation application of. What is a klystron amplifier, types, differences and their. The reflex klystron makes use of velocity modulation to transform a continuous electron beam into. Reflex klystron telecommunications engineering mechanics. Experiment4 study of the characteristics of the klystron tube. Another tube based on velocity modulation, and used to generate microwave energy, is the reflex klystron figure 29. Reflex klystron the analysis of a reflex klystron is similar to that of a twocavity klystron to some extent and is subjected to the following approximations. The reflex klystron oscillator is a lowpower, lowefficiency microwave oscillator, illustrated schematically in figure 118. 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. It is possible to produce oscillations in a klystron device which has only one cavity, through which electrons pass twice. The reflex klystron makes use of velocity modulation to transform a continuous electron beam into microwave power.
Reflex klystron pdf would have, spotydl download for mac, last man standing killbook of a bounty hunter pdf. Klystron multi cavity klystron, reflex klystron, working. Klystron power supply, klystron tube, isolator, frequency meter, variable attenuator, detector mount, waveguide stand, vswr meter and bnc cable. Which is impossible and not feasible to use other components for this purpose. Multi cavity klystron two cavity klystron used as lowpower microwave amplifier two cavity klystron. A sheetbeam klystron has been designed, built and tested in the klystron department at slac. This klystron is totally dissimilar from cavity klystron because it has a single cavity and used for modulation otherwise demodulation. But, these devices are replaced by semiconductor microwave devices. What is the principle of operation of a multicavity klystron. The name of this klystron is taken due to its reflex act of electron beam. This microwave generator, is a klystron that works on reflections and oscillations in a single cavity, which has a variable frequency. It is given the name reflex klystron because of its reflex action of electron beam. The schematic diagram of a reflex klystron tube is shown in fig. Find powerpoint presentations and slides using the power of, find free presentations research about two cavity reflex klystron ppt.
A cloud of thermionic electrons is generated by heating a filament inside a vacuum tube. I was an aetm3c in the navy and also remember those local oscillators. 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. Reflex klystron consists of an electron gun, a cathode filament, an anode cavity, and an electrode at the cathode potential. Voltages required for operation of reflex klystron tube such as beam, heater and reflector voltage. To study the characteristics of the reflex klystron tube and to determine its electronic tuning range. A reflex klystron is an obsolete type in which the electron beam was reflected back along its path by a high potential electrode, used. View and download powerpoint presentations on two cavity reflex klystron ppt. The two cavity reflex klystron is a widely used microwave amplifier operated by the principle of velocity modulation and current modulation.
Ph0101 unit 2 lecture 6 2 reflex klystrons the reflex klystron has been the most used. The main applications of a reflex klystron are as follows1. On this channel you can get education and knowledge for general issues and topics. Reflex klystron used as a lowpower microwave oscillator 2. The reflex klystron is also called as sutton tube invented by robert sutton. In this video, i have explained reflex klystron with following points 1. Klystron oscillator reflex klystron traveling wave tube. 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. 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. Typical operational problems with a klystron input drive power is too low and klystron is not saturated although this is required if the tube is included in a feedback loop reduced output power, efficiency, and increased output power amplitude jitter wrong cathode filament current wrong perveance. A microwave source of surprising range and endurance pdf. 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.
The reflex klystron amplifier is used as an oscillator in a modulator in microwave transmitters and radar receivers. 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. Klystron types there are two basic configurations of klystron tubes 1. This type of klystron is mostly used for the purpose of amplification of microwave length of frequencies. The 3k27 reflex klystron, with a fullrange tuner, is capable of covering the entire frequency range of 770 to 1150 megacycles by rotation of a single knob, and with an average power output of about 1 12 watts. What is probably the primary advantage of the reflex klystron over the twocavity klystron is the mechanism used to tune the device. Wband sheet beam extended interaction klystron eik. Microwave engineering reflex klystron this microwave generator, is a klystron that works on reflections and oscillations in a single cavity, which has a. It has two microwave cavity resonators the catcher and the buncher. Microwave engineering example problems in this chapter, let us have some fun by solving a few numerical problems related to microwaves. 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. A reflex klystron is an obsolete type in which the electron beam was reflected back along its path by a high potential electrode. Cavity grids and repeller are plane and parallel, and also very large in extent.
What are the assumptions for calculation of rf power in reflex klystron. Lowpower klystrons are used as oscillators in terrestrial microwave relay. The twocavity klystron has mechanical tuning, but the reflex. The klystron power supply also provides all the other d. What is the difference between the two cavity klystron. To study the characteristics of reflex klystron to study the characteristics of reflex klystron. The reflex klystron contains a reflector plate, referred to as the repeller, instead of. Of the resulting frequency spectrum only a narrow band, which. It is a low power tube with a single and work as an oscillator. Electrons are not intercepted by the cavity anode grid. The reflex klystron contains a reflector plate, referred to as the repeller, instead of the output cavity used in other types of klystrons. Microwave engineering ece questions and answers page 2. The reflex klystron another tube based on velocity modulation, and used to generate microwave energy, is the reflex klystron figure 29. Yes, they had a bellows that was externally adjusted to cause the separation between grids that coupled to a resonant chamber as reflex.511 708 1000 512 623 1466 651 326 546 385 129 569 1367 317 589 1305 502 396 319 1147 1247 726 61 1413 711 800 459 1202 516 12 1489