Two cavity klystron amplifiers working, amplification and. The frequency of resonance is mechanically adjustable by any of the methods discussed in section 104. In klystron amplifiers, which are physi cally long, it is difficult to keep the electron beam properly formed during its travel through the rf section. Operation the klystron was the first embodiment of the velocity modulation principle. Multicavity power klystrons repeller klystron twocavity klystron. In order to achieve higher overall gain, one way is to connect several two cavity tubes in cascade, feeding the output to each of.
The difference between the two cavity klystron and reflex klystron include the following. Reflex klystron used as a lowpower microwave oscillator 2. Reflex klystron is also known as a sutton klystron. In order to achieve higher overall gain, one way is to connect several twocavity tubes in cascade, feeding the output to each of. Multicavity power klystrons repeller klystron two cavity klystron. Mwe unit 3 topic 36 two cavity klystron amplifier duration. With the signal applied in the first cavity, we get weak bunches in the second cavity. Aug 30, 2012 klystron amplifier consist of following parts.
Understandexplain the principle of operation of a reflex klystron oscillator and derive an expression for the bunching parameter. The power gain of a two cavity klystron amplifier is about 30 db. 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. Amplification of such twocavity klystron is low and hence multicavity klystrons are used. The two cavity klystron is a widely used microwave amplifier operated by the principles of velocity and density modulation. Mar 27, 2020 this is the multiple choice questions in chapter 11. Microwave engineering reflex klystron tutorialspoint. The twocavity klystron is a widely used microwave amplifier operated by the principles of velocity and current modulatin. Due to the number of the resonant cavities klystrons are divided up into. What is a klystron amplifier, types, differences and their. Difference between two cavity klystron and reflex klystron. The two cavity klystron in figure 27a and b may be used either as an oscillator or an amplifier. The configuration shown in the figure is correct for oscillator operation.
Thus basically klystron amplifiers possess less power than their counterparts magnetron and travelling wave tube. Jul 31, 2018 technical article introduction to the two cavity klystron amplifier july 31, 2018 by mark mitchell klystron amplifiers are used in a variety of industries, including satellite systems, television broadcasting, radar, particle accelerators, and in the medical field. Reflex klystron oscillator operation application of. Microwave tubes and circuits from the book electronic communication systems by george kennedy. The basic process by which a two cavity klystron amplifier operates is as follows. It has two microwave cavity resonators the catcher and the buncher. Oct 01, 2014 0type tube is the twocavity klystron, and it is followed by the reflex klystron. The term klys comes from the stem form of a greek verb mentioning to the wave action breaking against a shore. This is the multiple choice questions in chapter 11. Dhanalakshmi college of engineering department of ece. The klystron shown in figure 119 has an integral cavity, but demountable cavities are also possible, as with amplifier klystrons. Klystron amplifier vacuum tube electrical engineering.
There is anode used to attract the electrons emitted from the cathode. The following figure depicts an example of multi cavity klystron amplifier. This name is given by the name of its inventor robert sutton, it allow the passage of electron beam through a single resonant cavity. Introduction to the twocavity klystron amplifier technical. Figure 28 shows a simplified sche matic of a triode amplifier with resonant circuits at both the input and the output. Two cavity klystron amplifiers working, amplification and applegate diagram by engineering funda duration. A klystron amplifier is a specific linearbeam vacuum tube, which is used as an amplifier for high resonant frequencies. Reflex klystron working, oscillator and applegate diagram. The vacuum tube consists of a cathode, which is heated by a filament. Explain the operation mechanism of two cavity klystron amplifier with neat sketch. Klystron usually will have two or more cavities as per gain and bandwidth requirements needed for different applications. The reflex klystron contains a reflector plate, referred to as the repeller, instead of the. Klystrons make use of the transittime effect by varying the velocity of an.
The twocavity amplifier has demonstrated a linear gain of 15 db and an unsaturated. What is the principle of operation of a multicavity klystron. Other articles where twocavity klystron is discussed. Klystron multi cavity klystron, reflex klystron, working. Input power is fed to the leading cavity, which applies a longitudinal rf electric field across the beam. The two cavity amplifier has demonstrated a linear gain of 15 db and an unsaturated. A klystron is a microwave vacuum tube using cavity resonators to produce velocity modulation of the electron beam and produce amplification. At a very high temperature, the cathode emits electrons. Current modulation will be seen in the working of 2 cavity klystron amplifier operation. Explain the operation principle of the cavity klystron with neat sketch.
Modified image based on a drawing by christian wolffcc bysa 3. The twocavity klystron is a widely used microwave amplifier operated by the principles of velocity and density modulation. Twocavity klystron as the name implies, this klystron uses two cavities. Between the cavities around the glass envelope a magnet is used in order to keep the electron beam in the center and in concentrated form at the end inside the glass envelope. The basic process by which a twocavity klystron amplifier operates is as follows. The copper klydtron calls all cooper tubular products tubes butthey designate diffreence type. Amplification of such two cavity klystron is low and hence multi cavity klystrons are used. The rf signal to be amplified is coupled to input cavity. The twocavity klystron is a widely used microwave amplifier operated by the. Klystron amplifiers include twocavity power klystrons and multicavity power klystrons. The electrons move from cathode to anode in the linear beam tube. Two cavity klystron amplifier specifications, working principle, applegate diagram and application.
Twts are generally at an advantage when low noise and frequency variability are useful. Klystron amplifier klystron amplifiers are high power microwave. Dhanalakshmi college of engineering department of ece ec6701. Dec 03, 2018 the klystron shown in figure 119 has an integral cavity, but demountable cavities are also possible, as with amplifier klystrons. May 31, 20 klystron amplifier the klystron amplifier can be used as an microwave oscillator or amplifier at low and high frequencies. Performance and operational features of this type of klystron the 3 cavity klystron, typical. Twystron is a hybrid amplifier which uses a combination of klystron and slow wave structures. Electrons emitted by the cathode are accelerated by the anode toward the input cavity.
By lowering the qs of the cavities and by introducing intermediate cavities, wider bandwidth operation can be achieved. The simplest klystron tube is the two cavity klystron. Explain the bunching process of a two cavity klystron and derive the expression for bunching parameter. One very important item that is required for highpower klystron amplifier operation is an axial magnetic field a magnetic field parallel to the axis of the klystron. There are two cavities known as buncher and catcher cavity. Draw and explain the working of two cavity klystron amplifier. Here a high velocity electron beam is formed, focused and sent down along a glass tube through an input cavity buncher, a field free drift space and an. A klystron uses special cavities which modulate the electric field around the axis the tube. Two cavity klystron amplifier specifications, working principle. The following figure depicts an example of multicavity klystron amplifier. Now understand the concept of reflex klystron in microwave engineering in details through following questions and answers. Slow wave structures are also otype but have nonresonant periodic structures for electron interactions. The feedback path provides energy of the proper delay and phase relationship to sustain oscillations. Explain the bunching process of a twocavity klystron and derive the expression for bunching parameter.
Sep 27, 2017 two cavity klystron amplifier s working, amplification and applegate diagram by engineering funda duration. The two cavities that were tested are designed to serve as bunching cavities for a highpower output cavity. Technical article introduction to the two cavity klystron amplifier july 31, 2018 by mark mitchell klystron amplifiers are used in a variety of industries, including satellite systems, television broadcasting, radar, particle accelerators, and in the medical field. The twocavity klystron in figure 27a and b may be used either as an oscillator or an amplifier. The twocavity klystron is a widely used microwave amplifier operated by the princi ples of velocity and current modulation. The operation of reflex klystron is understood by some assumptions.
In the twochamber klystron, the electron beam is injected into a resonant cavity. Microwave engineering cavity klystron tutorialspoint. In this tube there are two microwave cavity resonators, the catcher and the buncher. In the middle of these cavities, there is a grid allowing the. Klystron amplifiers are high power microwave vacuum tubes they are used in. What is the difference between the two cavity klystron. These will set up a field in the third cavity, which produces more concentrated bunches and.
As shown electron beam is generated by electron gun which passes through the space between input cavity i. For free materials of different engineering subjects use my android application named engineering. In the output cavity, signals are amplified by bunched electrons. Important question and answers on reflex klystron with. Introduction to the twocavity klystron amplifier technical articles.
Oct 03, 2016 mwe unit 3 topic 36 two cavity klystron amplifier duration. And the suffix tron is the place where the action occurs. Klystron amplifier the klystron amplifier can be used as an microwave oscillator or amplifier at low and high frequencies. In a klystron amplifier, a configuration of independent, resonant cavities excites longitudinal space charge waves on an electron beam and extracts power from the bunched beam figure 2. The two cavity klystron is the simplest klystron tube. The first cavity together with the first coupling device is called a buncher, while the second cavity with its coupling device is called a catcher. Two cavity klystron amplifier two cavity klystron amplifier is basically a velocity modulated tube. The electrons move with the field produced due to 83012 83012. The frequency of operation of a klystron is set by the sizes of the input and output cavities. An electronic oscillator can also be made from a klystron tube when the second cavity resonator is fed back to the first one with a coaxial cable or waveguide.
The electron beam is accelerated towards the anode cavity. The simplest klystron tube is the twocavity klystron. The velocities of electrons emitted from the cathode are modulated to produce a densitymodulated electron beam. 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.