These questions are likely to appear in the examination but if these questions doesnt appear in exam then m group doesnt take any resposibility. Try to initiate the following three common reflexes. Stationary phase and the theoryof measurement 1n expansion. The above observation suggests the 1n expansion scheme for large n, which incoorporates successively the. For this article, however, we will focus on another popular type. To study the characteristics of the reflex klystron tube and to determine its electronic tuning range.
Reflex klystron working, oscillator and applegate diagram youtube. The frequency of electromagnetic waves travelling in the waveguide is measured by the direct reading frequency meter which has resolution of 5 mhz. The electron gun emits the electron beam, which passes through the gap in the anode cavity. Klystron multi cavity klystron, reflex klystron, working.
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. The model klystron power supply skps610 is general purpose laboratory power supply which is specially designed to use for reflex klystron tubes of s to x band frequency range. The purpose of the next couple slides is to show the mathematical relations between polarization ellipse, e 0x, e 0y. Reflex klystron is one of the most commonly used microwave low power generators. 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. Second order bunching in an optical klystron sciencedirect. Reflex klystron free download as powerpoint presentation. The passthrough effect, therefore, contributes to the overall operating efficiency of the transmitter.
A loop coupling is used inside the cavity to get the output. 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. In this video, i have explained reflex klystron with following points 1. The reflex klystron makes use of velocity modulation to transform a continuous electron beam into. Microwave engineering directional couplers tutorialspoint. Process induced damage rules fine featured processes utilize cmp chemicalmechanical polishing to achieve planarity. What 2 ions process is involved in depolization and repolarization. Describe the basic theory of operation of klystrons including multicavity and reflex klystrons. A reflex klystron is an obsolete type in which the electron beam was reflected back along its path by a high potential electrode, used. All these components are enclosed in a glass envelope. A reflex klystron achieves the same bunching by causing the beam to reverse. The following figure shows the image of a directional coupler. A reflex klystron is operated at 5ghz with dc beam voltage v, beam current 20ma, repeller space lcm for 1.
The bunches of electrons excite microwaves in the output cavity of the klystron. 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. Dielectric relaxation studies of polyvinylpyrrolidone pvp and polyvinylbutyral pvb in benzene solutions at microwave frequency. The main difference between two cavity reflex klystron amplifier. Many of us are acquainted with some reflexes by virtue of having physical exams, e. A klystron is characterized by high power, large size, high stability, high gain, and high operating voltages. History the fundamental principle behind the klystron, velocity modulation, has an interesting history. Lowpower klystrons are used as oscillators in terrestrial microwave relay communications links, while highpower klystrons are.
After the focusing electrodes there is a cavity resonator which encircles the glass envelope. A klystron is basically a vacuum tube with input and output structures replaced with resonant cavities known as buncher cavity and catcher cavity. Electron beam current modulation in a klystron is the key phenomenon that accounts for klystron gain and rf power generation. Microwave engineering reflex klystron this microwave generator, is a klystron that works on reflections and oscillations in a single cavity, which has a. Sutton used a crt electron gun to generate a focused electron. Full text of klystrons and microwave triodes see other formats. Typicallifetimesof8,000to15,000hourshavebeenreported. The name klystron comes from the greek verb klyzo referring to the action of waves breaking against a shore, and the suffix.
This page on klystron vs magnetron describes difference between klystron and magnetron. 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 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 twocavity klystron utilizes an electron source heater, an anode, and a cathode like a conventional. Experiment4 study of the characteristics of the klystron tube. 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. Sep 27, 2017 in this video, i have explained reflex klystron with following points 1. It is reliable power source with very high regulation and low ripple contents. In this klystron, a single pair of grids does the functions of both the buncher and the catcher grids. A change in the klystron 2 voltage regime does not change the working signal phase difference in the shoulders 1 and 2, i. Derive expressions for bunched beam current and efficiency. Reflex klystron is also known as a sutton klystron. Geometric optics blinn college physics 2426 terry honan k.
Reflex klystron telecommunications engineering mechanics. The process xt and yt are said to be orthogonal if r x,y t 1,t 2 0 for all t 1 and t 2. Give the range for beam voltage for reflex klystron power supply ans. When the lower ram thermometer reads the test temperature the test can proceed. And this is how the bunching process occurs in the klystron tube. The reflex klystron operates in a different mode for each additional cycle that the electrons remain in the repeller field. The bunching cavities regulate the speed of the electrons so that they arrive in bunches at the output cavity. We know that british carefully planned all the developmental steps for their radar sets, including the use of microwaves when elsewhere the upper limit of usable frequencies was around 500 mhz. To study the characteristics of the reflex klystron tube and to determine the its electronic tuning range. The beam voltage is set in the range of 0205v after this voltage the device will be spoilt and cannot be used further. Try to initiate the following three common reflexes then.
To study the mode characteristics of the reflex klystron tube and to determine its electronic tuning range. Safety precautions do not use excessive force when testing the kneejerk reflex. Reflex testing in the laboratory introductory background reflex testing is another way of obtaining information about a patient by health care personnel. One major type is the reflex klystron, which is used primarily as an oscillator. The reflex klystron another tube based on velocity modulation, and used to generate microwave energy, is the reflex klystron figure 29. The reflex klystron makes use of velocity modulation to transform a continuous electron beam into microwave power. Effective cmp requires that the variations in feature density on a layer be restricted.
How are oscillations produced in a reflex klystron. Cavity of a repeller klystron another tube based on velocity modulation, and used to generate microwave energy, is the reflex klystron repeller klystron. A microwave source of surprising range and endurance pdf. Electron emitted from the cathode are accelerated and passed through the positive resonator towards negative reflector, which. Reflex klystron vacuum tube manufactured goods free. After the tests are complete press the enable button to deactivate the ecc and flip the power switch to off. 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. Another tube based on velocity modulation, and used to generate microwave energy, is the reflex klystron figure 29. Microwave engineering reflex klystron tutorialspoint. How reflex klystron works electrical engineering stack exchange. Dielectric relaxation studies of polyvinylpyrrolidone pvp. What are the assumptions for calculation of rf power in reflex klystron. The microwaves flow into the waveguide, which transports them to the accelerator.
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. Directional coupler is used to couple the microwave power which may be unidirectional or bidirectional. A klystron is a specialized linearbeam vacuum tube, invented in 1937 by american electrical. 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. Because of its most fundamental nature we can choose our units to make c have the exact value c. Due to the cross term, the ellipse is rotated relative to the x and y directions. Describe the construction, basic theories of operation, and. Explain the bunching process of a twocavity klystron and derive the expression for.
Reflex klystron consists of an electron gun, a cathode filament, an anode cavity, and an electrode at the cathode potential. The reflex klystron is fitted on the klystron mount and energized by a regulated power supply. The maximum thermionic current density is given by. 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. Microwave engineering ece questions and answers page 6. It had its beginnings in europe and russia in the early 1930s. Reflex klystron oscillator pdf source of an electronbeam and the radiofrequency por tion of the klystron is independent of the electron source. Box 118, s221 00 lund, sweden received 28 february 1997 abstract a method to achieve spatial bunching on the double. Klystron a power amplifier tube used to amplify weak microwave energy provided by a radio frequency exciter to a high power level for a radar transmitter. Klystron power supply, klystron tube, isolator, frequency meter, variable attenuator, detector mount, waveguide stand, vswr meter and bnc cable. Cavity grids and repeller are plane and parallel, and also very large in extent. Respiration and heartbeat are controlled by the medulla oblangata. Have your partner sit in a chair with legs crossed, so the top leg. The development of reflex klystron as local oscillator.
Introduction to the twocavity klystron amplifier technical articles. With the help of applegate diagram illustrate the phenomenon of bunching. 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. The difference between reflex and twomulti cavity klystron is that, reflex klystron uses single cavity for modulationdemodulation. Explain the basic theory of operation of travelingwave tubes and backwardwave oscillators. Important question and answers on reflex klystron with. Learn vocabulary, terms, and more with flashcards, games, and other study tools.
Now understand the concept of reflex klystron in microwave engineering in details through following questions and answers. The expected lifetime of a tetrode in uhf service is usually shorter than a klystron ofthesamepowerlevel. Why is pulse modulation required in reflex klystron. Mode 1 is obtained when the repeller voltage produces an electron transit time of 34 cycle. The antenna rules deal with process induced gate oxide damage caused when exposed polysilicon and metal structures. The internal electrode arrangement of the tube is given in the drawing of fig. Two cavity klystron is a amplifier where as reflex klystron is an oscillator. The klystron power supply skps610 has built in modulation facilities of amplitude and. Klystron vs magnetrondifference between klystron,magnetron. Directional coupler is a 4port waveguide junction consisting of a primary main waveguide and a secondary auxiliary waveguide. Lowpower klystrons are used as oscillators in terrestrial microwave relay. Question how does a reflex arc help to protect the body from harm.
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. Using the instron compressiontensile tester in conjunction. It is the purpose of this paper to show that this is. It is known by this name due to its reflex action of electron beam. An electron linac producing beam power up to 15 kw. A klystron also known as a klystron tube or klystron amplifier is a vacuum.
248 1122 1524 773 1341 105 589 1295 367 769 534 1092 782 756 613 862 1454 330 1362 97 1076 1271 1178 567 913 881 456 1310 767 1291 69 671 1241 1359 98 221 1242 118 736 237 1497 1012 1073 94 561 607 194 71 1490 515