Radio waves travel throughout space at frequencies between 10 khz and 100ghz per second. Travelling wave tube twt is an electronic vacuum microwave device. This chapter provides the basic description of the twta structure and its various components. What makes the travelling wave tube twt able to amplify. A helix twt consists of an electron gun and a slow wave structure. Traveling wave tube article about traveling wave tube by.
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. The traveling wave tube twt is a highgain, lownoise, widebandwidth microwave amplifier. Twts are used as highpower microwave amplifiers in. 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. 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. The general theory of operation of various types of twt designs is discussed. Pdf new model of a travellingwave tube researchgate. The operating principle of a twt is based on the interaction of an electromagnetic wave. Travelling wave tube basics, working and applications twt. Travelling wave definition and meaning collins english. 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. The twt was invented by rudolf kompfner in 1942 in england, for this reason he appears in our microwave hall of fame. Traveling wave definition of traveling wave by merriam. Satellites directv, direcpc, pagers, telephones, xmradio, etc.
A wave pulse is a disturbance that moves through a medium a periodic wave is a periodic disturbance that moves through a medium. It is capable of gains greater than 40 db with bandwidths exceeding an octave. In this paper the basic operation of travellingwave. Vacuum tube electron gun magnet and focusing structure rf input helix rf output collector the detailed diagram of helix twt can be viewed as, the simplified circuit is, working operation.
Traveling wave tube an overview sciencedirect topics. 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 envelope has a positive and a negative side, but we generally only talk about the positive half because that. Such type of wave occurs for a short duration for a few microseconds but cause a much disturbance in the line. They are a mixture of magnetism and electricity that moves at the speed of light with a defined length and frequency. Energy is often transferred as the wave propagates, but matter may not be. 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. The curve that shows the amplitude of the traveling wave at each point along the basilar membrane is called its envelope. A travelling wave tube comprising an electron beam producing system, an electron beam collector and a delay line operatively connected between said electron beam generating system and said electron beam collector, and wherein said tube further comprises a resonance section interposed in said delay line and having a increased delay time. In this video, i have explained helix which is a travelling wave tube or amplifier for microwave frequency. Therefore, this discussion applies to both sspa and twtas. Radio waves work as a form of electromagnetic radiation.
All content on this website, including dictionary, thesaurus, literature, geography, and other reference data is for informational purposes only. Traveling wave tube amplifiers are widely used in satellite applications to provide signal power amplification at high frequencies. Twt traveling wave tube is an electronic device used to amplify microwave radio frequency rf signals to higher power levels. Industrial assessment of the microwave power tube industry. Traveling waves amplitudes over a discrete set of frequencies. It has been found that helices more accurate in pitch can be wound on a smooth drill rod than on the threaded rod formerly. Travelling waves 1 introduction one of the cornerstones in the study of both linear and nonlinear pdes is the wave propagation. Extending the life of a traveling wave tube the traveling wave tube twt is the heart of your twt amplifier twta, as well as its most expensive component. Other articles where travelingwave tube is discussed. Principle application areas include radar, electronic countermeasures, telecommunications. 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. The travelingwave tube the travelingwave tube twt is a highgain, lownoise, widebandwidth microwave amplifier. The travelingwave tube can be used as a medium or high power microwave, amplifier. Additionally, the department of energy doe uses large, highpower klystron.
The strings we will deal with are fastened to rigid supports at each end, so the solution 3. An electron gun focusses an electron beam with the velocity of light. Helix travelling wave tube twt specifications, working. This product is known as a travelingwave tube amplifier twta. The anode plates, when at zero potential, which means when the axial electric field is at a node, the electron beam velocity. Publication date 1960 topics travelingwave tubes publisher kansas state university collection. Traveling wave theory definition of traveling wave. Kompfner in 1943, and the principle of twt amplification was demonstrated by him at birmingham. The traveling wave tube amplifier twta together with the klystron are. Design of a travelingwave tube by moore, larry lex. The microwave power tube industry is one of many defense related industries that have been affected by this new environment.
The individual atoms and molecules in the medium oscillate about their equilibrium position, but their average position does not change. Travelling wave is a temporary wave that creates a disturbance and moves along the transmission line at a constant speed. Military radar systems missile guidance, aircraft missile tracking, jamming systems civilian radar systems civilian microwave radios e. The twt, because of its construction and working principle has enormous bandwidths and low noise. These are generally used to amplify microwave signals over broad bandwidths.
A bandwidth of 1 octave is one in which the upper frequency is twice the lower frequency. Solid state amplifiers sspa used mostly at sband also exhibit performance characteristics similar to twtas. The travellingwave tube twt is a device wherein an electron beam interacts with a. The interaction between the electrons and the waves in a travelingwave tube can, with reasonable assumptions, be formulated completely by the field theory. The center loss section included in previous tubes will be omitted. Stream tracks and playlists from travelling wave on your desktop or mobile device. 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. Travelling wave definition of travelling wave by the. This page was split from our microwave tube page and we added some content and photos thanks to terry cisco. Sivanandam research scholar, sathyabama university chennai 600 119 email. Klystrons, traveling wave tubes, magnetrons, crossedfield. 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. The helix travelling wave tubetwt, can be split into a number of separate major elements. Enhanced features for design of traveling wave tubes using.
A traveling wave tube twt is a hightech vacuum tube. Google as you are already aware of the procedure of generation of electron beam and the usage of slow wave structure to ensure the interaction of rf wave with electron beam in the helical str. The twt, because of its construction and working principle has. 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 electrons are decelerated and the electromagnetic field gets stronger. Travellingwave tube definition of travellingwave tube. The transient wave is set up in the transmission line mainly due to switching, faults and lightning. Output traveling wave tube how is output traveling wave. Engineering college, chennai 600 095 abstract a traveling wave tube twt is a vital component of satellite communication. This new tube will use the smallerdiameter helix which is to be supported in a glass tube. Travelling wave tube is a cylindrical structure which contains an electron gun from a cathode 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.
They possess regular patterns and have the longest wavelengths in the. Travellingwave tube twt is a wideband microwave amplifier. 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. Such an approach to this problem can bring out many physical phenomena useful in the design of such a tube that are not apparent from the circuit theory. In a travelingwave tube the kinetic energy of electrons is transferred to the power of an electromagnetic wave rfsignal. Travelingwave tube article about travelingwave tube by. Travelling wave theory definition of travelling wave. The dod uses microwave power tubes in a wide variety of system applications, and will continue to do so well into the next century. Lawrence ives2, and david chernin3 abstract traveling wave tubes twts are vacuum devices invented in the early 1940s for.
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