Article pdf available in ieee transactions on microwave theory and techniques 5210. This amplifier is mainly used as an oscillator within a modulator of radar receivers as well as microwave transmitters. 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. Klystron multi cavity klystron, reflex klystron, working. Utiliz ing silicon micromachining techniques, the design and fabrication concept of a mono lithic thz vacuumtube. The reflex klystron contains a reflector plate, referred to as the. The authors propose a new approach to thz power generation. The schematic diagram of a reflex klystron tube is shown in fig. Dhanalakshmi college of engineering department of ece ec6701. The dependence of these characteristics on the beam current, beam voltage, re flector voltage, load, and other klystron design factors. It is of the same rugqedized construction as the bendix 6116tk62 the tube is, division, eatontown, new jersey publication no. Microwave engineering reflex klystron tutorialspoint. From each mode and the band of frequencies over which the circuit can be tuned. Microwave tubes 6940 type tk58 reflex klystron, tuned xband reflex klystron, designed for use.
It is assumed that oscillations already exist in the tube and they are sustained by its. Optimization of micromachined reflex klystrons for operation at. In this klystron, a single pair of grids does the functions of both the buncher and the catcher grids. What are the assumptions for calculation of rf power in reflex klystron. The ranges of all these voltages are given in the specification data sheet. Us3060342a reflex klystron having a cavity resonator with a. Klystron, including the reflex and multicavity klystron multistage depressed collector msdc klystron inductive output tube iot traveling wave tube twt crossedfield tube coaxial magnetron gyrotron planar triode highfrequency tetrode. When used as an amplifier, the weak microwave signal to be amplified is applied to the buncher cavity through a coaxial cable or waveguide, and the amplified signal is extracted from the catcher cavity.
The electrons are fired into one end of the tube by an electron gun. Reflex klystron free download as powerpoint presentation. Reflex klystron is invented by robert sutton, so another name of this klystron amplifier is sutton tube. Why is pulse modulation required in reflex klystron. A singlecavity klystron in which the electron beam is reflected back through the cavity resonator by a repelling electrode having a negative voltage. 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. Bookmark file pdf microwave engineering schaum series 1. Different characteristics of reflex klystron can be determined using the whole associated package for reflex klystron experiments. Twystron is a hybrid amplifier which uses a combination of klystron and slow wave structures. This type of klystron is mostly used for the purpose of amplification of microwave length of frequencies. The brothers russell and sigurd varian of stanford university are the. The operation of reflex klystron is understood by some assumptions. The reflex klystron utilizes velocity modulation to convert regular electron beam energy into microwave power. Mar 24, 2016 microwave frequencies are millimeter waves so we need to generate them through amplifiers or oscillators,in this video we will learn generation of microwave frequencies using reflex klystron.
A helix travelling wave tube operates at 4 ghz, under a beam voltage of 10 kv and. Ec1740 microwave and radarengineering microwave tubes outline 1. In this tube there are two microwave cavity resonators, the catcher and the buncher. View reflex klystron from wireless 10123 at saveetha university. The electrons while passing through the anode cavity, gain some velocity. Jan 07, 2019 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 electron gun consists of the cathode k, the focusing. Reflex klystron oscillators ieee xplore a reflex klystron oscillator. Reflex klystron consists of an electron gun, a cathode filament, an anode. The first papers on the theory of the reflex klystron were published by the soviet physicists ia. A klystron is a vacuum tube that can be used either as a generator or as an amplifier of power, at microwave frequencies. The principle of velocityvariation, first used in heil oscillators, was also used in other microwave amplifying and oscillating tubes.
Another tube based on velocity modulation, and used to generate microwave energy, is the reflex klystron figure 29. The main difference between two cavity reflex klystron amplifier and reflex klystron is that the output cavity is omitted in reflex klystron and the repeller or reflector electrode, placed a very. The constructional details of this reflex klystron is as shown in the following figure. A sutton tube, or reflex klystron, is a type of vacuum tube used to generate microwaves. The difference between reflex and twomulti cavity klystron is that, reflex klystron uses single cavity for modulationdemodulation. Microwave frequencies are millimeter waves so we need to generate them through amplifiers or oscillators,in this video we will learn generation of microwave frequencies using reflex klystron.
Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed. After passing through the resonant cavity they are reflected by a negatively charged reflector electrode for another pass through the cavity, where they are then collected. Klystrons are the most efficient of linear beam microwave tubes. 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. The application for klystron with integral cavities is usually credited in the early 1939 to hahn and metcalf and to russell and sigurd varian, two brothers that. In the reflex klystron, the electron beam passes through a single resonant cavity. Klystron types there are two basic configurations of klystron tubes 1. Which is impossible and not feasible to use other components for this purpose.
A klystron is a specialized linearbeam vacuum tube evacuated electron tube the name klystron comes from the stem form. In wikipedia it says that, the electrons are fired into one end of the tube by an electron gun. Inspire your inbox sign up for daily fun facts about this day in history, updates, and special offers. And there is a reflector or repeller to repel the electrons. Two cavity klystron is a microwave vacuum tube using two cavity resonator to produce velocity modulation of electron beam and to produce amplification. But for instance, the very old 723ab reflex klystron, which gives a watt or two of rf, uses ordinary receiver type power supplies, less than 1 kv and no xray precautions were ever required. Microwave engineering cavity klystron for the generation and amplification of microwaves, there is a need of some special tubes called as microwave tubes. The reflex klystron contains a reflector plate, referred to as the repeller, instead of the output cavity used in other types of klystrons.
Oct 01, 2014 0type tube is the twocavity klystron, and it is followed by the reflex klystron. Experiment4 study of the characteristics of the klystron tube. Voltages required for operation of reflex klystron tube such as beam, heater and reflector voltage. The electron beam is velocity modulated when it first passes through the cavity. Slow wave structure microwave linear beam tubes o type microwave communication slow wave structure video lecture from microwave linear beam tubes o type chapter of microwave communication subject for all. The simplest klystron tube is the twocavity klystron. Reflex klystron thermally tuned description the bendixa type tk68 tube is a thermally tuned c band reflex oscillator. The klystron power supply also provides all the other d. Reflex klystrons were developed in 1940 by the soviet engineers n. Klystron oscillator reflex klystron traveling wave tube magnetron klystron. Klystron tube article about klystron tube by the free. This disadvantage of twocavity klystron can be overcome by reflex klystron, because it has single cavity. What is a klystron amplifier, types, differences and their. Now, let us see bunching process and the modes and reflex klystron, this vertical axis represent the distance from the cavity gap towards the repeller plate, and this horizontal axis represent the time taken by the electrons in moving in the repeller space.
The reflex klystron another tube based on velocity modulation, and used to generate microwave energy, is the reflex klystron figure 29. Pdf optimization of micromachined reflex klystrons for operation. Klystron power supply, klystron tube, isolator, frequency meter, variable attenuator, detector mount, waveguide stand, vswr meter and bnc cable. Mar 24, 2016 working of reflex klystron oscillator. 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. I have a doubt on how exactly a reflex klystron worksas an rf source. 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. Microwave engineering cavity klystron tutorialspoint. The reflex version of the klystron, perfected at sperry and. However, these devices are substituted with semiconductor microwave devices. Aug 27, 2016 of course, klystrons come in all sizes. Note in figure that the resonator potential is common to the resonator cavity, the accelerating grid, and the entire body of the tube. It is assumed that oscillations already exist in the tube and they are sustained by its operation.
The reflex klystron makes use of velocity modulation to transform a continuous electron beam into. To study the characteristics of reflex klystron to study the characteristics of reflex klystron. Reflex klystron article about reflex klystron by the free. Klystron tube 2k25 the klystron tube 2k25 is a single cavity variable frequency microwave generator of low power and low efficiency. Piskunov, working as a group, and, independently, by the soviet engineer v. Klystron, thermionic electron tube that generates or amplifies microwaves by controlling the speed of a stream of electrons. In order to generate microwave frequencies we need amplifiers or oscillators,in this video we will learn how a reflex klystron oscillator works in.
A microwave source of surprising range and endurance george caryotakis stanford linear accelerator center, stanford university, stanford ca 94309 abstract this year marks the 60th anniversary of the birth of the klystron at stanford university. The paramount o type tube is the two cavity klystron followed by the reflex klystron. To study the characteristics of the reflex klystron tube and to determine its electronic tuning range. The simplest klystron tube is the reflex klystron klystron.