To study the characteristics of the reflex klystron tube and to determine its electronic tuning range. It is possible to produce oscillations in a klystron device which has only one cavity, through which electrons pass twice. So, working principle of reflex klystron is velocity and current modulation. Typicallifetimesof8,000to15,000hourshavebeenreported. The reflex version of the klystron, perfected at sperry and in british laboratories, served as the local oscillator in superheterodyne radar receivers. Reflex klystron calculator converters and calculators.
Reflex klystron working, oscillator and applegate diagram engineering funda. The reflex klystron makes use of velocity modulation to transform a continuous electron beam into microwave power. The reflex klystron contains a reflector plate, referred to as the repeller, instead of the output cavity used in other types of klystrons. Together, the magnetron and the klystron made possible airborne sband radar, a major factor in securing air superiority for the raf. Important question and answers on reflex klystron with. The bunches of electrons excite microwaves in the output cavity of the klystron. 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. Reflex klystron consists of an electron gun, a cathode filament, an anode cavity, and an electrode at the cathode potential. Download free microwave engineering pozar 4th edition solution. So, electron beam is injected from the cathode and that injected beam travel with a.
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. When we switch on the klystron, the heater of reflex klystron is heated up. Electron beams are produced from a source and the cavity klystrons are employed to amplify the signals. The bunching cavities regulate the speed of the electrons so that they arrive in bunches at the output cavity. Electron emitted from the cathode are accelerated and passed through the positive resonator towards negative reflector, which retards and, finally, reflects the electron. This name is given by the name of its inventor robert sutton, it allow the passage of electron beam through a single resonant cavity. Reflex klystron reduced power from the bunches, in reflex klystron, reduces the reflex klystron of the cavity oscillations and causes a decrease in output power. Reflex klystron amplifier electronics club microwave. Reflex klystron working free download as powerpoint presentation. Difference between two cavity klystron and reflex klystron. The multi cavity klystron consist of a glass envelope in which there is an electron gun composed of heater and cathode. Apr 12, 2020 microwave engineering lab viva question bank, engineering edurev notes is made by best teachers of. First of all, consider an electron a which passes through the resonator.
The expected lifetime of a tetrode in uhf service is usually shorter than a klystron ofthesamepowerlevel. Pdf design of pulse power supply for klystron and its. The reflex klystron oscillator is a lowpower, lowefficiency microwave oscillator, illustrated schematically in figure 118. Pdf optimization of micromachined reflex klystrons for operation. When switch on the circuit, the electrons starts emitting from the cathode. Find powerpoint presentations and slides using the power of, find free presentations research about reflex klystron ppt.
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. The focusing electrodes keep the flow of electrons in the center of glass envelope. This document is highly rated by students and has been viewed 73310 times. I think u1 may have to do with getting the reflex klystron started. This is the reflex klystron oscillator, which will now be described. Microwave engineering kg reddy college of engineering.
The operation of reflex klystron is a little bit different from the twocavity klystron because there is only one cavity. The reflex klystron oscillator is a vacuum tube microwave signal generator and its operation depends on the principle of velocity modulation and transit time. A cloud of thermionic electrons is generated by heating a filament inside a vacuum tube. Reflex klystron working vacuum tube microwave scribd. Frequency extension source modules to extend signal generator capability from 50 to 325 ghz. It is given the name reflex klystron because of its reflex action of electron beam. Following equation or formula is used for reflex klystron calculator. 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. Reflex klystron free download as powerpoint presentation. The schematic diagram of a reflex klystron tube is shown in fig. This type of klystron oscillator is called a reflex klystron because of the reflex action of the electron beam.
The pulse generator driving this klystron has maximum peak power rating of 14. This microwave generator, is a klystron that works on reflections and oscillations in a single cavity, which has a variable frequency. Define reflex klystrons, some characteristics and applications. The microwaves flow into the waveguide, which transports them to the.
On this channel you can get education and knowledge for general issues and topics. The whole set up is as shown in the following figure. Caryotakis, performance of a 150mw sband klystron, aip conf. Which of the following operating frequencies is used for the modern loran navigational system. Three power sources are required for reflex klystron operation.
The reflex klystron another tube based on velocity modulation, and used to generate microwave energy, is the reflex klystron figure 29. Following is the list of useful converters and calculators. Klystron oscillator reflex klystron traveling wave tube magnetron. Reflex klystron is one of the most commonly used microwave low power generators.
The reflex klystron makes use of velocity modulation to transform a continuous electron beam into. Cavity of a repeller klystron another tube based on velocity modulation, and used to generate microwave energy, is the reflex klystron repeller klystron. Reflex klystron oscillator operation application of. The main difference between two cavity reflex klystron amplifier. These electrons move at a uniform speed towards the anode until they are attracted by it. Displaying powerpoint presentation on reflex klystron available to view or download. Reflex klystron telecommunications engineering mechanics. Wiring with a repeller klystron, and an example given low power repeller klystron tube repeller klystrons are often used in older radar sets as local oscillators or as oscillators in measurement sets. This single cavity is work like a buncher as well as catcher cavity.
F input signal to the buncher cavity with the help of loop coupling. Klystron amplifier vacuum tube electrical engineering. Now understand the concept of reflex klystron in microwave engineering in details through following questions and answers. In this klystron, a single pair of grids does the functions of both the buncher and the catcher grids.
Reflex klystron working, oscillator and applegate diagram engineering funda, microwave engineering in this video, i have explained reflex klystron with following points 1. Voltages required for operation of reflex klystron tube such as beam, heater and reflector voltage. The klystron power supply also provides all the other d. Reflex klystron used as a lowpower microwave oscillator 2. Klystron power supply, klystron tube, isolator, frequency meter, variable attenuator, detector mount, waveguide stand, vswr meter and bnc cable. Optimization of micromachined reflex klystrons for operation at. The reflex klystron is an oscillator with a built in feedback mechanism. Microwave engineering cavity klystron tutorialspoint. Microwave engineering reflex klystron tutorialspoint. Experiment4 study of the characteristics of the klystron tube. Twystron is a hybrid amplifier which uses a combination of klystron and slow wave structures. Reflex klystron article about reflex klystron by the. 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. The essential elements of klystron are electron beams and cavity resonators.
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. Reflex klystron is a lowpower, lowefficiency microwave oscillator another tube based on velocity modulation, and used to generate microwave energy, it contain cathod. Diode drive cavity idler cavities output cavity collector guidefield solenoid. Klausst 72fvm 36betwixt 22 reflex klystron, volker muehlhaus 21asdf44 the process is referred to as modulation. A collector is present at the end to collect the electrons. Ph0101 unit 2 lecture 6 4 working the cathode emits electrons which are accelerated forward by an accelerating grid with a positive voltage on it and focused into a narrow beam. Slow wave structures are also otype but have nonresonant periodic structures for electron interactions. Klystron, including the reflex and multicavity klystron. Intensive work, however, has led to products that offer higher output powers and extended operating lifetime, while retaining the benefits inherent in tetrode devices. Klystron multi cavity klystron, reflex klystron, working. 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. Microwave communication questions and answers pdf free download. Two cavity klystron amplifiers working, amplification and applegate diagram by engineering funda.
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