Traveling wave tube development for a serrodyne reentrant amplifier preface a nasagoddard space flight center supporting research task entitled, direct rf to rf converters for communications satellites required the study of various transponder schemes for directly converting one microwave frequency to another in connection with providing. Travelling wave tube operation in order to design a helixtype traveling wave tube amplifier twta, it is necessary to understand the operating physics of a travelling wave tube twt. Industrial assessment of the microwave power tube industry. The strings we will deal with are fastened to rigid supports at each end, so the solution 3.
It has been found that helices more accurate in pitch can be wound on a smooth drill rod than on the threaded rod formerly. Travellingwave tube definition of travellingwave tube by. A megawattlevel surface wave oscillator in yband with large. This chapter provides the basic description of the twta structure and its various components.
The patent haeff filed in 1933 for a primitive type of traveling wave tube. Ifi has been using twts in thier twtas since 1953 and have the most extensive line of testing amplifiers and amplifier systems on the market today. Traveling wave tubes twt space electron devices key features space qualified, proven technology highreliability highest efficiency in the industry radiation and conductioncooled. The travelingwave tube in the history of telecommunication. This product is known as a travelingwave tube amplifier twta. Nov 22, 20 the submillimeter wave, or terahertz, part of the electromagnetic spectrum falls between the frequencies of 0. Physics 231 standing waves 2 any point x on the string executes simple harmonic motion in time, and at any instant the shape of the string is given by sin.
The a600 units are 220vac, 3phase powered and consist of a panel, a chassis, internal twt, frame, and covers. Traveling wave tube amplifiers are widely used in satellite applications to provide signal power amplification at high frequencies. The design and performance of the twobeamtype and the singlebeamtype experimental electron wave tubes are described. Therefore, this discussion applies to both sspa and twtas. Principles of traveling wave tubes artech house radar. Welcome to the most trusted and comprehensive tubes.
The travelling wave tube can be used for wideband rf amplifier designs where even now it performs well against devices using newer technologies. Evaluation of commercial traveling wave tubes for application in direct rf to rf transponders by i. Travelling wave tube amplifiers twtas for space applications. Rf input is sent to one end of the helix and the output is drawn from the other end of the helix. Principles of traveling wave tubes artech house radar library. The submillimeter wave, or terahertz, part of the electromagnetic spectrum falls between the frequencies of 0. The traveling wave tube twt is a highgain, lownoise, widebandwidth microwave amplifier.
This product is known as a traveling wave tube amplifier twta. Unlike the tubes discussed so far, magnetrons are the crossfield tubes in which the electric and magnetic fields cross, i. The envelope has a positive and a negative side, but we generally only talk about the positive half because that. This new tube will use the smallerdiameter helix which is to be supported in a glass tube. The heated cathode at one end of the tube produces a beam of electrons and is attracted to the collector at the other end of the tube. The traveling wave tube can be used as a medium or high power microwave, amplifier. The wave still travels down the helix wire at the speed of light, but the coiled shape causes the wave to travel a much greater total distance than the electron beam. Travelingwave tube article about travelingwave tube by. In this report, only the helix type of travelingwave tube will be considered. Traveling wave tube development i for a serrodyne re.
Helix studies as mentioned in the last progress report, a largescale model of the helix used in the traveling wave tube was constructed. An electron tube in which a stream of electrons interacts continuously or repeatedly with a guided electromagnetic wave moving substantially in synchronism with it, in such a way that there is a net transfer of energy from the stream to the wave. From the principle of fourier analysis, an anharmonic traveling wave can be decomposed into a sum of traveling harmonic wave components, i. The series a600 traveling wave tube amplifiers, hereafter referred to as the a600, are selfcontainedinstruments suitable for bench or rack use. Andre and others published new model of a travelling wave tube find, read and cite all the research you need on researchgate. An electron gun focusses an electron beam with the velocity of light. Traveling wave theory definition of traveling wave. Other articles where travelingwave tube is discussed. A wide variety of applications were covered by these twtas. The center loss section included in previous tubes will be omitted. Summarythe start oscillation condition for the backwardwave oscillator and the operation of the travelingwave tube amplifier at the kompfner dip point are. In this work, a compact oversized swo driven by the annular relativistic electron beam is proposed and experimented with operation frequency in. A potential application of the beacon source is for investigating the atmospheric effects on qband 37 to 42 ghz and vwband 71 to 76 ghz satellitetoground signals.
The traveling wave tube in the history of telecommunication damien f. The dod uses microwave power tubes in a wide variety of system applications, and will continue to do so well into the next century. Twave by travelling wave, released 30 october 20 1. All those conditions are fulfilled by the travelingwave tube twt. A coupled mode description of the backward wave oscillator and. In twt, it was observed that electrons when made to interact with rf, for a longer time, than in klystron, resulted in higher efficiency. Traveling wave definition is a wave in which the particles of the medium move progressively in the direction of the wave propagation with such a gradation of speeds that the faster overtake the slower and are themselves in turn overtaken. Kband twt efficiency and wideband performance 100 110 120 140 150 160 170.
Additionally, the department of energy doe uses large, highpower klystron. Traveling wave tubes consist of three elements an electron gun for generating the electron beam, the rf circuit, where the beam interacts and amplifies radio frequency waves, and the collector, where the spent beam is collected and dissipated. Pdf new model of a travellingwave tube researchgate. There are two different basic technical approaches of twts. Minenna,1,2,3, fr ed eric andr e,3 yves elskens,2 jeanfran. In this activity, the cochlea will be unwound and only some of the structures are shown to make it easier to follow how the basilar membrane and cochlea function to transduce sounds. The traveling wave tube the traveling wave tube twt is a highgain, lownoise, widebandwidth microwave amplifier.
The twt belongs to a category of linear beam tubes, such as the klystron, in which the radio wave is amplified by absorbing power from a beam of electrons as it. The twt, because of its construction and working principle has enormous bandwidths and low noise. Clay prillaman communications satellite research branch abstract a traveling wave tube twt finds application in communica tion satellite transponders where it is used to simultaneously am plify many signals over a broad spectral range. The speed at which the wave travels down the tube can be varied by changing the number of turns or the diameter of the turns in the helix wire. The true history of the traveling wave tube request pdf. Introduction the analysis of traveling wave tubes as amplifiers has been carried out by j. This chapter provides the basic description of the twta structure and. These are generally used to amplify microwave signals over broad bandwidths. This page was split from our microwave tube page and we added some content and photos thanks to terry cisco. Traveling wave here simply means that the wave moves from the base to the apex of the basilar membrane. These types of structures enable higher power han dling through both thermal capability and higher voltage operation without giving rise to backward wave oscilla. In pierces paper, the action of the field on the electron beam and the reaction of the beam back on the field were formulated. The traveling wave tube is a form of thermionic valve or tube that is still used for high power microwave amplifier designs. The twt was invented by rudolf kompfner in 1942 in england, for this reason he appears in our microwave hall of fame.
Energy is often transferred as the wave propagates, but matter may not be. In radio and telecommunication, a travelingwave antenna is a class of antenna that uses a traveling wave on a guiding structure as the main radiating mechanism. Traveling wave tube article about traveling wave tube by. Nov 29, 2010 traveling wave tubetraveling wave tube is an electric vacuum device, intended for generation and amplification of microwave oscillations. Coupledcavity travelingwave tube electronics britannica.
A helixlike slow wave structure is used for the electron wave beam interaction and a collector at the end of the tube stops the electron beam after it has travelled through the tube. Traveling waves amplitudes over a discrete set of frequencies. Principles of traveling wave tubes artech house radar library a. Travelling wave theory definition of travelling wave. Solid state amplifiers sspa used mostly at sband also exhibit performance characteristics similar to twtas. The helix twt, however, has no particular bandwidth limitations, and, for all practical purposes, an octave bandwidth 100 percent is attainable.
It consists of a cylindrical helical coil which, in the absence of an electron beam, is capable of supporting a wave along the axis of the helix with a phase velocity substantially less than the light velocity. Travelling wave tube twt the travelingwave tube can be used as a medium or high power microwave, amplifier. Travelling wave definition of travelling wave by the. The twt belongs to a category of linear beam tubes, such as the klystron, in which the radio wave is amplified by. It is capable of gains greater than 40 db with bandwidths exceeding an octave. Travelling wave tube is a cylindrical structure which contains an electron gun from a cathode tube. In this report, only the helix type of traveling wave tube will be considered. Enjoy the videos and music you love, upload original content, and share it all with friends, family, and the world on youtube. Travelingwave tubetravelingwave tube is an electric vacuum device, intended for generation and amplification of microwave oscillations.
Travelling wave tube amplifiers twtas for space applications bosch has provided twtas which satisfied requirements of nasa, esa, intelsat, inmarsat, european, asian and us commercial programs. Twt traveling wave tube is an electronic device used to amplify microwave radio frequency rf signals to higher power levels. Klystrons, traveling wave tubes, magnetrons, crossedfield. Traveling wave resources are compiled in this industrial portal which provides information on manufacturers, distributors and service companies in the tubes. They take therefore a special position under the velocitymodulated tubes. A bandwidth of 1 octave is one in which the upper frequency is twice the lower frequency.
Travellingwave tube definition of travellingwave tube. The main elements of a travelingwave tube twt are 1 an electron gun, 2 a focusing structure that keeps the electrons in a linear path, 3 an rf circuit that causes rf. A wave is a recognizable signal which is transferred from one part of the medium to another part with a recognizable speed of propagation. We have experience with both helix twts and coupled cavity. The travelingwave tube the travelingwave tube twt is a highgain, lownoise, widebandwidth microwave amplifier. Travelling wave definition of travelling wave by the free.
At the same time, one of the drawbacks of the travelling wave theory is the difficulty of accounting for the ears exquisite fine tuning. Other articles where coupledcavity travelingwave tube is discussed. Travelling waves 1 introduction one of the cornerstones in the study of both linear and nonlinear pdes is the wave propagation. The curve that shows the amplitude of the traveling wave at each point along the basilar membrane is called its envelope. The traveling wave tube is a form of thermionic valve or tube that is used for high power microwave amplifier designs. A traveling wave tube twt, pronounced twit or traveling wave tube amplifier twta, pronounced tweeta is a specialized vacuum tube that is used in electronics to amplify radio frequency rf signals in the microwave range. For these purposes the device uses the interaction between. May 30, 2015 enjoy the videos and music you love, upload original content, and share it all with friends, family, and the world on youtube. Operation moon bounce butrica 1997 and they transmitted the first. Traveling wave definition of traveling wave by merriamwebster. Patent and trademark office patent pending recognition. The microwave power tube industry is one of many defense related industries that have been affected by this new environment. The panel serves as a mounting for the controls and monitoring meters. The twt was invented by rudolf kompfner in 1942 in england, for this reason he.
The patent haeff filed in 1933 for a primitive type of travelingwave tube. A travelingwave tube twt, pronounced twit or travelingwave tube amplifier twta, pronounced tweeta is a specialized vacuum tube that is used in electronics to amplify radio frequency rf signals in the microwave range. Offers detailed discussions of operating principles of helix and coupledcavity traveling wave tubes, descriptions of rf interactions of electrons with electric fields, and the basic theories of electron bunching and traveling wave interactions. Their distinguishing feature is that the radiofrequency current that generates the radio waves travels through the antenna in one direction. On reason of the special lownoise characteristic often they are in use as an active rf amplifier element in receivers additional. Traveling wave definition of traveling wave by merriam. Traveling wave theory definition of traveling wave theory. Practical travelling wave tube amplifiers twtas have applications in both receiver and transmitter systems, and come in all shapes and sizes, but they all consist of three basic partsthe tube, the tube mount which includes the beam focussing magnets and the power supply. Operation is similar to that of a klystron, except that coupledcavity twts are designed with attenuation between the slowwave structure instead of a drift tube.
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