It had its beginnings in europe and russia in the early 1930s. Another tube based on velocity modulation, and used to generate microwave energy, is the reflex klystron. Different characteristics of reflex klystron can be determined using the whole associated package for reflex klystron experiments. History the fundamental principle behind the klystron, velocity modulation, has an interesting history. Reflex klystron article about reflex klystron by the free. For this article, however, we will focus on another popular type.
Nd 15 reflex klystron if a fraction of the output power is fed back to the input cavity and if the loop gain has a magnitude of unity with a phase shift of. Principles of twocavity klystrons twocavity klystron geometry. Klystron vs magnetrondifference between klystron,magnetron. Frequency extension source modules to extend signal generator capability from 50 to 325 ghz.
Reflex klystron or repeller klystron another tube based on velocity modulation, and used to generate microwave energy, is the reflex klystron repeller klystron. What is the difference between the two cavity klystron. It covers basics of klystron and magnetron and mention difference between them. The reflex klystron amplifier is used as an oscillator in a modulator in microwave transmitters and radar receivers. Jul 31, 2018 one major type is the reflex klystron, which is used primarily as an oscillator. Nov 09, 2016 reflex klystron working, oscillator and applegate diagram engineering funda. The electron gun emits the electron beam, which passes through the gap in the anode cavity. Reflex klystron used as a lowpower microwave oscillator 2. The reflex klystron contains a reflector plate, referred to as the repeller, instead of the output cavity used in other types of klystrons. But, these devices are replaced by semiconductor microwave devices. Now understand the concept of reflex klystron in microwave engineering in details through following questions and answers. 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. Reflex klystron working, oscillator and applegate diagram engineering funda. This amplifier is mainly used as an oscillator within a modulator of radar receivers as well as microwave transmitters.
A second type of reflex klystron, known as the 2k28, uses an external cavity. 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. It is a low power tube with a single and work as an oscillator. Optimization of micromachined reflex klystrons for operation at. This type of klystron is mostly used for the purpose of amplification of microwave length of frequencies. Diode drive cavity idler cavities output cavity collector guidefield solenoid. Klystron power supply, klystron tube, isolator, frequency meter, variable attenuator, detector mount, waveguide stand, vswr meter and bnc cable. 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.
Another tube based on velocity modulation, and used to generate microwave energy, is the reflex klystron figure 29. Multi cavity klystron used as lowpower microwave amplifier reflex klystron reflex klystron reflex klystron single reentrant cavity as a resonator. Reflex klystron oscillator pdf source of an electronbeam and the radiofrequency por tion of the klystron is independent of the electron source. Reflex klystron is also known as a sutton klystron. Apr 29, 2012 the klystron is used in television transmission, particle accelerators, and powerful radar, like that in the dew line which defended north america from attack. One major type is the reflex klystron, which is used primarily as an oscillator. The reflex version of the klystron, perfected at sperry and in british laboratories, served as the local oscillator in superheterodyne radar receivers. A loop coupling is used inside the cavity to get the output. 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. Pdf study of a reflex klystron emmanuel markoulakis. Microwave engineering cavity klystron tutorialspoint. Electron emitted from the cathode are accelerated and passed through the positive resonator towards negative reflector, which.
Consistent flying of beam from four to five miles out using a single horn gave a constant signal path. This name is given by the name of its inventor robert sutton, it allow the passage of electron beam through a single resonant cavity. Which is impossible and not feasible to use other components for this purpose. As rf amplifier it requires 30w in input to generate 25 kw pulses at frequencies. You and your group are certainly to be congratulated. Microwave engineering cavity klystron for the generation and amplification of microwaves, there is a need of some special tubes called as microwave. Microwave engineering cavity klystron for the generation and amplification of microwaves, there is a need of some special tubes called as microwave tubes. It is known by this name due to its reflex action of electron beam. Entire group enthusiastic and indebted for klystron unit.
What is a klystron amplifier, types, differences and their. 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 expected lifetime of a tetrode in uhf service is usually shorter than a klystron ofthesamepowerlevel. The klystron with internal or external feedback built in its design can function as oscillator. Reflex klystron article about reflex klystron by the. 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.
The twocavity klystron utilizes an electron source heater, an anode, and a cathode like a conventional. Efficient microwave tubes usually operate on the theory of electron velocity modulation concept. Reflex klystron oscillator operation application of. The reflex klystron has been the most used source of microwave power in laboratory applications. The electron beam emitted from the cathode is accelerated by the grid and passes through the cavity anode to the repeller space between. This document is highly rated by students and has been viewed 73373 times. 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. View and download powerpoint presentations on two cavity reflex klystron ppt.
Threecavity linear beam klystron, designed for pulsed operation in tacan ground or shipboard beacons. Klystron, thermionic electron tube that generates or amplifies microwaves by controlling the speed of a stream of electrons. 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. Reflex klystron vacuum tube electromagnetism scribd. The klystron is used in television transmission, particle accelerators, and powerful radar, like that in the dew line which defended north america from attack. 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 reflex klystron makes use of velocity modulation to transform a continuous electron beam into. It is possible to produce oscillations in a klystron device which has only one cavity, through which electrons pass twice. In this klystron, a single pair of grids does the functions of both the buncher and the catcher grids.
This klystron is totally dissimilar from cavity klystron because it has a single cavity and used for modulation otherwise demodulation. 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. To study the characteristics of the reflex klystron tube and to determine its electronic tuning range. To study the characteristics of reflex klystron the reflex klystron utilizes velocity modulation to convert regular electron beam energy into microwave power. Dhanalakshmi college of engineering department of ece. The electron beam emitted from the cathode is accelerated by the grid and passes through the cavity anode to the repeller space between the cavity anode and the repeller electrode. Find powerpoint presentations and slides using the power of, find free presentations research about two cavity reflex klystron ppt. Klystrons there are two basic configurations of klystron tubes. Reflex klystron consists of an electron gun, a cathode filament, an anode cavity, and an electrode at the cathode potential. Other articles where twocavity klystron is discussed. Klystron oscillator reflex klystron traveling wave tube magnetron. Read more microwave tubes and read more klystron basics.
The reflex klystron is also called as sutton tube invented by robert sutton. A klystron is basically a vacuum tube with input and output structures replaced with resonant cavities known as buncher cavity and catcher cavity. The main difference between two cavity reflex klystron amplifier. The schematic diagram of a reflex klystron tube is shown in fig. The difference between reflex and twomulti cavity klystron is that, reflex klystron uses single cavity for modulationdemodulation. Experiment4 study of the characteristics of the klystron tube. Reflex klystron is invented by robert sutton, so another name of this klystron amplifier is sutton tube.
The passthrough effect, therefore, contributes to the overall operating efficiency of the transmitter. 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. Microwave engineering reflex klystron this microwave generator, is a klystron that works on reflections and oscillations in a single cavity, which has a. This page on klystron vs magnetron describes difference between klystron and magnetron. Reflex klystron working free download as powerpoint presentation. Lowpower klystrons are used as oscillators in terrestrial microwave relay. The reflex klystron contains a reflector plate, referred to as the. Important question and answers on reflex klystron with. Single reentrant cavity as a resonator the electron beam. Beam signals detected four miles out, good signals at eight miles.
Scribd is the worlds largest social reading and publishing site. Jan 07, 2019 reflex klystron pdf posted on january 7, 2019 by admin 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. Electron emitted from the cathode are accelerated and passed through the positive resonator towards negative reflector, which retards and, finally, reflects the electron. Reflex klystron pdf would have, spotydl download for mac, last man standing killbook of a bounty hunter pdf. All these components are enclosed in a glass envelope. The feedback required to maintain oscillations within the cavity is obtained by reversing the beam and sending it back. Together, the magnetron and the klystron made possible airborne s. May 02, 2020 microwave engineering lab viva question bank, engineering edurev notes is made by best teachers of. A reflex klystron is an obsolete type in which the electron beam was reflected back along its path by a high potential electrode. Cavity of a repeller klystron another tube based on velocity modulation, and used to generate microwave energy, is the reflex klystron repeller klystron. Klystron multi cavity klystron, reflex klystron, working. Introduction to the twocavity klystron amplifier technical. Jan 31, 2019 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. This is the reflex klystron oscillator, which will now be described.
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 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. Reflex klystron is one of the most commonly used microwave low power generators. Of the resulting frequency spectrum only a narrow band, which.
To study the characteristics of reflex klystron labappara. The name of this klystron is taken due to its reflex act of electron beam. Microwave engineering reflex klystron tutorialspoint. However, these devices are substituted with semiconductor microwave devices. At microwave frequencies, however, the transit time or angle is large compared to. Rigid design shear strength precisely engineered experiments.
Klystron oscillator reflex klystron traveling wave tube biological effect of microwaves. The reflex klystron oscillator is a lowpower, lowefficiency microwave oscillator, illustrated schematically in figure 118. As shown in the given diagram it is composed of heater, cathode, focusing electrodes and repeller anode. Typicallifetimesof8,000to15,000hourshavebeenreported. Reflex klystron free download as powerpoint presentation. After the focusing electrodes there is a cavity resonator which encircles the glass envelope. The reflex klystron makes use of velocity modulation to transform a continuous electron beam into microwave power. Explain the working principle of reflex klystron and derive expression for power and efficiency.