Exact solutions of travelling wave model via dynamical system method wang, heng, chen, longwei, and liu. Travelling wave tube is a cylindrical structure which contains an electron gun from a cathode tube. Pdf in this paper we study the travelling wave solutions of a reactiondiffusion system with a slow reaction and a slow diffusion for one component find, read and cite all the research you. The electrons are decelerated and the electromagnetic field gets stronger. Enhanced features for design of traveling wave tubes using. Electrons are fired from cathode and received from collectors. Traveling wave tube amplifiers are widely used in satellite applications to provide signal power amplification at high frequencies. Ions are injected at one end, and the time taken to travel the length of the tube is recorded. Heater and cathode act as electron gun, and they are on the side rf input.
The constant coefficient telegraphers equations form. The interaction between the electrons and the waves in a travelingwave tube can, with reasonable assumptions, be formulated completely by the field theory. 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. In that case, pressure will be in phase with displacementthat is, the pressure reaches its maximum or minimum value when the gas is at an extreme of its oscillatory motion. The travelling wave analysis consists of finding solutions of the telegraphers equations, bearing in mind the characteristics of the transmission lines, the equipment to which they will be connected and the nature of the signals likely to be experienced in power system transient situations. Novel wband ridgeloaded folded waveguide traveling wave. Now vx consists of two terms each of which is a function of two variables time and distance.
Microwave tube, a key element in the modern world of communication ernst bosch thales electronic system gmbh, ulm, germany ernst. A wide variety of applications were covered by these twtas. From this, the velocity of travel can ies can also be determined. 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. In a travelingwave tube the kinetic energy of electrons is transferred to the power of an electromagnetic wave rfsignal. Travelling wave tube amplifiers twtas for space applications. A device which operates in this way is known as a travellingwave tube twt. 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. A novel slowwave structure of the travelingwave tube consisting of rings and. Rsr 210n reutech radar systems, p o box 686, stellenbosch 7599, south africa tel.
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. Drifttube ion mobility spectrometry dtims drift tube ims uses a long, gasfilled tube with a constant and relatively low electric field. What links here related changes upload file special pages permanent link page information wikidata item cite this page. Not all equations admit travelling wave solutions, as demonstrated below. Other articles where coupledcavity travelingwave tube is discussed. Helix studies as mentioned in the last progress report, a largescale model of the helix used in the travelingwave tube was constructed. Andre and others published new model of a travelling wave tube find, read and cite all the research you need on researchgate.
Coupledcavity travelingwave tube electronics britannica. The pdf24 creator installs for you a virtual pdf printer so that you can print your. The traveling wave tube twt is a highgain, lownoise, widebandwidth microwave amplifier. Travelling wave tubes are broadband microwave devices which have no cavity resonators like klystrons. Travelling wave darkgazepsychnoise band from brazil. A twt is capable of gains from 40 to 70 db with bandwidths exceeding two octaves. When enough air builds up inside a twt tube that is inactive, they have the ability to interact with the electron beam inside the tube when it is operational. Pdf the travelingwave tube in the history of telecommunication. Pdf traveling wave solutions of a reactiondiffusion. A pdf creator and a pdf converter makes the conversion possible. The company began making miniature twts in 1972 and developed the first micro twt in the early 1980s. It is capable of gains greater than 40 db with bandwidths exceeding an octave. 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.
Appendix e includes the boundary and input file of the electron gun design. Traveling wave solutions of a diffusive seir epidemic model with nonlinear incidence rate zhao, lin. Such an approach to this problem can bring out many physical phenomena useful in the design of such a. Energy and power in waves 1 energy in a string the kinetic energy of a mass m with velocity v is 1 2 mv2. 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. Linearized gain of a twt v e2ev0m12 e and m are electron charge and mass. The travelingwave tube is a critical subsystem for satellite data transmission. An improved travelingwavebased fault location method. This page was split from our microwave tube page and we added some content and photos thanks to terry cisco. Twt has become the microwave amplifier of choice for many commercial and military systems. Amplification is done through the prolonged interaction between an electron beam and radio frequency. This obviously maintains the vacuum that is required for the operation of the twt. Highefficiency kband space travelingwave tube amplifier for nearearth high data rate communications rainee n.
The feasibility study was divided into four phases. Highefficiency kband space travelingwave tube amplifier. This chapter provides the basic description of the twta structure and its various components. The next available frequency band is the qband whereas today the experience on travelling wave tubes in this frequency band is low. Andre and others published new model of a travellingwave tube find, read and cite all the research you need on researchgate. From the principle of fourier analysis, an anharmonic traveling wave can be decomposed into a sum of traveling harmonic wave components, i.
Extending the life of a traveling wave tube handling. Solid state amplifiers sspa used mostly at sband also exhibit performance characteristics similar to twtas. The main attraction of these devices is their very high gain 3060 db, linear characteristics and 12 octave bandwidth. In transverse waves the particles of the medium move perpendicular to the direction in which the wave travels. This plane wave is constant in the x and z directions. A highpower travellingwave tube based on a periodic beam interaction in unloaded waveguide. A bandwidth of 1 octave is one in which the upper frequency is twice the lower frequency. It is capable of providing 160 w output power and operates over the frequency band 2. Such type of wave occurs for a short duration for a few microseconds but cause a much disturbance in the line.
The traveling wave tube in the history of telecommunication damien f. Travelling wave is a temporary wave that creates a disturbance and moves along the transmission line at a constant speed. Pdf new model of a travellingwave tube researchgate. A comparison of the 3 main forms of ion mobility spectrometry. In this video, i have explained travelling wave tube with following topics. A travelingwave tube twt, pronounced twit or travelingwave tube amplifier twta. The transient wave is set up in the transmission line mainly due to switching, faults and lightning. The methods to create pdf files explained here are free and easy to use. The essential features of a typical travelling wave tube introduction in the past few years, several radio amateurs have employed travelling wave tubes twts, colloquially known as twits, as microwave power amplifiers. A design study for a lowvoltage, highefficiency, and widebandwidth wband travelingwave tube using a symmetric double vshaped microstrip meanderline slowwave structure combined with a sheet. The travelingwave tube amplifiers contained in the instrumentation series are laboratory. The traveling wave tube is a critical subsystem for satellite data transmission. Lawrence ives2, and david chernin3 abstract traveling wave tubes twts are vacuum devices invented in the early 1940s for.
The n20180 is an ultrawideband helix travelling wave tube. The helix twt, however, has no particular bandwidth limitations, and, for all practical purposes, an octave bandwidth 100 percent is attainable. In general, it follows that any solution to the wave equation can be obtained as a superposition of two travelling waves. Travelling wave tube basics, working and applications twt. Miniature traveling wave tubes photonis has been manufacturing traveling wave tubes twts since their invention in the early 1940s. Travelling wave tube twt the twt, because of its construction and working principle has enormous bandwidths and low noise. Travellingwave tubes chapter 14 microwave and rf vacuum. Helix studies as mentioned in the last progress report, a largescale model of the helix used in the travelingwave. Kaband, outdoor traveling wave tube amplifiers twtas. 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. When the tube is operating, the getter will remove these random air molecules, but not when the tube is turned off.
836 639 1144 659 1545 1073 873 933 1432 837 227 35 1100 605 1367 1239 379 336 1177 1296 901 1456 1436 372 928 255 1537 601 682 443 74 567 773 1021 843 1060 1360 954