Reflex klystron working, oscillator and applegate diagram. Klystron production is now proceeding at tubes per month. If you need an oscillator, a reflex tube will work fine, but it is old school technology. Reflex klystron is a microwave device that works on principle of velocity modulation in addition to current modulation. The main difference between two cavity reflex klystron amplifier. Scribd is the worlds largest social reading and publishing site. Of the resulting frequency spectrum only a narrow band, which. Increasing klystron efficiency using com and bac tuning and application to the 5045 klystron aaron jensen, andy haase, erik jongewaard, mark kemp and jeff neilson technology and innovation directorate slac national accelerator laboratory menlo park, ca, usa, 94025 abstract. The reflex klystron makes use of velocity modulation to transform a continuous electron beam into. Klystron amplification, power output, and efficiency can be greatly improved by the addition of intermediate cavities between the input and output cavities of the basic klystron. The reflex klystron oscillator is a lowpower, lowefficiency microwave oscillator, illustrated schematically in figure 118.
A klystron is a specialized linearbeam vacuum tube evacuated electron tube the name klystron comes from the stem form. Microwave engineering cavity klystron for the generation and amplification of microwaves, there is a need of some special tubes called as microwave tubes. 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. To study the characteristics of the reflex klystron tube and to determine the its electronic tuning range. When the beam of electrons reflect back to the grid due to the repeller voltage in reflector plate,how the grid decelerates the returning electrons and how they release their energy to the grid.
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. Connect the detector output to y input and sawtooth output of the klystron of power supply to xinput of scope fig. Microwave engineering cavity klystron tutorialspoint. Important question and answers on reflex klystron with. It is possible to produce oscillations in a klystron device which has only one cavity, through which electrons pass twice. Modulation is accomplished by varying the velocity of the beam, which. In this klystron, a single pair of grids does the functions of both the buncher and the catcher grids. Following are the benefits or advantages of klystron. After the electron gun there are two focusing electrodes used to keep the electron beam in the center around the glass envelope. This unit came from a working environment but has not been tested. A klystron is a vacuum tube that can be used either as a generator or as an amplifier of power, at microwave frequencies. The schematic diagram of a reflex klystron tube is shown in fig.
I was an aetm3c in the navy and also remember those local oscillators. The klystron is a linearbeam device that overcomes the transittime limitations of a gridcontrolled tube by accelerating an electron stream to a high velocity before it is modulated. Reflex klystron oscillator operation application of. Klystron power supply, klystron tube, isolator, frequency meter, variable attenuator, detector mount, waveguide stand, vswr meter and bnc cable. The mathematically simple formalism proposed earlier for calculating electromagnetic parameters of a reentrant cavity barroso et al. The tube provides 5 kw cw output power at 1497 mhz and is permanentmagnet focused with a four. International journal of infrared and millimeter waves 268.
It is given the name reflex klystron because of its reflex action of electron beam. A klystron looks and works something like an organ pipe. Difference between two cavity klystron and reflex klystron. 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 one of the most commonly used microwave low power generators. Reflex klystron consists of an electron gun, a cathode filament, an anode cavity, and an electrode at the cathode potential. It has two microwave cavity resonators the catcher and the buncher. Varian reflex klystron tube va 220b etheric beam locator. Another tube based on velocity modulation, and used to generate microwave energy, is the reflex klystron figure 29. Klystron types there are two basic configurations of klystron tubes 1. Additional cavities serve to velocitymodulate the electron beam and produce an increase in the energy available at the output. To study the characteristics of the reflex klystron tube and to determine its electronic tuning range. Modern semiconductor technology has effectively replaced the reflex klystron in most applications. Klystron power supply, klystron tube, isolator, frequency meter, variable attenuator, detector.
Several effects limiting the gain enhancement are calculate d. The conventional vacuum tubes, such as triodes, tetrodes, and pentodes, are. This microwave generator, is a klystron that works on reflections and oscillations in a single cavity, which has a variable frequency. Introduction the klystrons for the ground test accelerator gta. Reflex klystron free download as powerpoint presentation. This type of klystron is mostly used for the purpose of amplification of microwave length of frequencies. Klystron is a microwave generator compare slacs large, highpower microwave generator klystron below with this much smaller one magnetron right from a typical microwave oven.
Spontaneou s emission and gain are theo retically studied as functio n of electron energy and wavelength. Performance evaluation of klystron beam focusingsystem. The klystron has produced over 1 mw at the new frcqucncy. Pre 1939 the transit time in triodes and tethrodes and pentodes was a limiting factor to produce high frequency amplifiers up t. Electromagnetic analysis of reentrant klystron 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.
Reflex klystron article about reflex klystron by the. Due to dc voltage in the cavity circuit, rf noise is generated. Slacpub16466 increasing klystron efficiency using com. I have a doubt on how exactly a reflex klystron worksas an rf source. Microwave engineering reflex klystron tutorialspoint. Klystron and microwave department capabilities and xband. In wikipedia it says that, the electrons are fired into one end of the tube by an electron gun. Multi cavity klystron two cavity klystronused as lowpower microwave amplifier two. The klystron is at heart a narrowband vacuumtube ampli. A klystron is a specialized linearbeam vacuum tube, invented in 1937 by american electrical. Reflex klystron used as a lowpower microwave oscillator 2. Yes, they had a bellows that was externally adjusted to cause the separation between grids that coupled to a resonant chamber as reflex.
Department of electronics and communication engineering ec 2405 optical and microwave lab manual vii sem ece 1 prepared by m. In the last lecture, we discussed conventional tubes and their high frequency. The optical klystron is a modificatio n of the undulato r which can be used to improve the gain in a free electro n laser. Varian va 220b klystron tube reflex klystron tube uhv vacuum this particular item is similar to the ones used in the dr. The reflex klystron contains a reflector plate, referred to as the repeller, instead of the output cavity used in other types of klystrons. The electronic tuning range of the reflex klystron is usually referred to as the variation in frequency between half power pointsthe points in the oscillating mode where the power output is half the maximum output in the mode. Cavity of a repeller klystron another tube based on velocity modulation, and used to generate microwave energy, is the reflex klystron repeller klystron.
A singlecavity klystron in which the electron beam is reflected back through the cavity resonator by a repelling electrode having a negative voltage. The klystron is the ubiquitous source of rf power in accelerators today. First, you need to determine what your need for a klystron is. In fact, according to kek injector operating statistics during 10 years in 2000s, the failures in focusing solenoids were the most frequent reasons to exchange klystron assemblies among the other. Performance characteristics of the cebaf klystron amplifier. The klystron beam focusing system is one of the key components in the whole system. Blowing into the organ pipe produces a flow of air. Who tv series from england in the 70s in the tv show it was called an etheric beam locator. The klystron was the first embodiment of the velocity modulation principle. 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. 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. Klystron modes measurement of klystron characteristics. Klystron multi cavity klystron, reflex klystron, working.
All these products are designed, developed and manufactured at an iso 9001. There are three generic types of microwave tubes, with the categorization based on the character of the interaction between the microwave structures used and the. Hannurkar raja ramanna centre for advanced technology, indore, india. Characteristics of a reflectiontype microwave modulator. In klystron, each cavity operates independently and there is no mutual coupling. Abstract the design and simulation of a multibeam reentrant.
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