The singlestage travelling wave power amplifier was designed usi ng 0. Travelling wave tube amplifier type ahpa102000 description the ahpa102000 is a travelling wave tube amplifier comprising of an albacom ly2 pulsed i band travelling wave tube and matched, modular power supply. 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. A female connector is used on the input to mate with the male connector used on the output of new focus highspeed photodetectors. Mode ac uplink formats reply downlink format side lobe suppression fruit. 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. 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. Cpi twtas are the most efficient high power amplifiers for satellite communications uplinks. Quarterwave high power traveling wave tube amplifiers twta. 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. Microwave tube, a key element in the modern world of communication ernst bosch thales electronic system gmbh, ulm, germany ernst. 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.
Highefficiency kband space travelingwave tube amplifier. Manual and automated microwave high power cw and pulsed testing. Minenna,1,2,3, fr ed eric andr e,3 yves elskens,2 jeanfran. A second appendix notes a constant amplitude, linear sawtooth generator which may be used to shift the phase of frequency of the rf output from a twt amplifier.
Highefficiency kband space traveling wave tube amplifier for nearearth high data rate communications rainee n. Jackson abstract the problem of a helixtype traveling wave amplifier tube, under certain simplifying assumptions, is solved as a boundaryvalue problem. Teardown of a microwave amplifier and a traveling wave tube kerry wong. Cpi satcom kuband outdoor travelling wave tube amplifiers twta. Travelling wave tubes twts helix travelling wave tubes are widely used wave amplifiersmainly consisting in. This video depicts the amplification process in a travelingwave tube twt. The rf performance characteristics such as high gain, gain flatness, low phase distortion and high linearity shall be com. Discussion of the characteristics of travelingwave tube amplifiers and several applications. A highly sophisticated power supply is required by twt. Analysis and pic simulation of a gyrotron travelling wave tube. And while mcl prides itself on providing stateoftheart amplifiers designed to extend tube life in a. Attenuators placed along the rf circuit prevent the reflected wave from traveling back to the cathode. Travelling wave tube is a cylindrical structure which contains an electron gun from a cathode tube.
An electron gun focusses an electron beam with the velocity of light. The analysis of a kaband gyrotron travelling wave tube gyrotwt amplifier using a uniform cylindrical waveguide as its interaction circuit has been. Solid state amplifiers are being increasingly used instead of electronic vacuum tubes to feed accelerating cavities with radio frequency power in the 100 kw range. To read and print pdf files, download adobe acrobat reader. High power traveling wave tube amplifiers twta, high. The travelingwave tube amplifiers contained in the instrumentation series are laboratory instruments designed for general purpose microwave applications. Although there are various types of twt, two major categories are. The operation of the da can perhaps be most easily understood when explained in terms of the travelingwave tube amplifier twta. The proposed amplifier is designed on travelling wave tube twt fig. Design of high voltage power converter for traveling wave. The twt was invented by rudolf kompfner in 1942 in england, for this reason he appears in our microwave hall of fame. In order to meet the severe requirements of traveling wave tube amplifier twta, a novel twostage topology high voltage converter for twta is proposed.
The other difference between terms are provided here. Feb 14, 2015 in a traveling wave tube the kinetic energy of electrons is transferred to the power of an electromagnetic wave rfsignal. The travelingwave tube in the history of telecommunication. Extending the life of a traveling wave tube handling. High efficiency is required in order to optimize rf output power and heat dissipation. The cavity resonator has been designed and constructed. A travelingwave tube or travelingwave tube amplifier is a specialized vacuum tube that is used in electronics to amplify radio frequency signals in the microwave range. Pdf new model of a travellingwave tube researchgate. Twta stands for travelling wave tube amplifier and sspa stands for solid state power amplifier. These traveling wave tube amplifiers twtas offer power levels from 20 w to 1 kw cw and up to 70 kw pulsed.
Amplification is done through the prolonged interaction between an electron beam and radio frequency. The cathode produces an electron beam with the velocity of light at the collector, guided by a magnetic field. Travelling wave tube amplifier vacuum tube free 30day. Satcom systems travelling wave tube amplifier twta we offer the widest range and best performance twtas in the world, extremely aggressive pricing structure.
Troubleshooting a traveling wave tube amplifier engineering. The results indicate that the presence of the beam in the helix causes the normal mode to break up. These are well known twta travelling wave tube amplifier and the sspa solid state power amplifier. Power is obtained from the combination of hundreds of transistor amplifier modules. Travelling wave tubes are broadband microwave devices which have no cavity resonators like klystrons. Before continuing about troubleshooting of traveling wave tube amplifier we have some initial considerations include. Click the button below to directly contact the supplier.
The traveling wave tube in the history of telecommunication damien f. Scm01 the basics of travelling wave tube amplifiers 14. Travelingwave tubes resonator of the type used in klystrons. This chapter provides the basic description of the twta structure and its various components. Extensive inorbit data has been collected from over 2000 mpas in 1991 and 1993. It is also essentially a broad band device and no tuning is necessary. Traveling wave tubes twts are widely used in the radar and communications system as rf power amplifiers. The backward wave oscillator bwo the electron beam from an electron gun passes through a wire helix and generates an electric field that induces voltage with the helix wire. Two type of twtas, the helix for broadband applications and the coupled cavity for highpower applications are predominant. An experimental, low profile, broadband travelling wave tube amplifier by nicolaos vassilopoulos submitted in fulfilment of the academic requirements for the degree of doctor of philosophy in the department of electronic engineering, university of natal.
This obviously maintains the vacuum that is required for the operation of the twt. The traveling wave tube is a form of thermionic valve or tube that is used for high power microwave amplifier designs. 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. Traveling wave tube development for a serrodyne reentrant amplifier abstract program objectives were to study serrodyne techniques and determine twt characteristics to incorporate in serrodyne reentrant amplifiers. Discussion of the characteristics of traveling wave tube amplifiers and several applications.
Cpi satcom kuband outdoor travelling wave tube amplifiers twta is available to buy in increments of 1 frequencies from. This chapter provides the basic description of the twta structure and. Helix twt in which the radio waves interact with the electron beam while tr. Helix studies as mentioned in the last progress report, a largescale model of the helix used in the traveling wave tube was constructed. 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.
The electrons are decelerated and the electromagnetic field gets stronger. The function of modules such as electron gun, magnet, collector is same as used in klystron described below. Twtas traveling wave tube amplifiers are an alternative to the high power sspas, and can be higher power. A travelingwave tube twt, pronounced twit or travelingwave tube amplifier twta. Travelling wave tube amplifier vacuum tube free 30. A longitudinal helix slow wave nonresonant guide is placed at the centre of the tube that provides a low impedance transmission line for the rf energy within the tube. The electron beam is generated by an electron gun where the cathode can be either a thermo electric cathode or a cold cnt. Ligabased slow wave structure for a thz vacuum amplifier.
Mt3600 antenna mount travelling wave tube power amplifier for satellite uplink applications. Helix studies as mentioned in the last progress report, a largescale model of the helix used in the travelingwave. Development of a 220 ghz 50 w sheet beam travelling wave. The model 1421 and 1422 broadband amplifiers are housed in a compact unit whose input and output connectors are wiltron kconnectors.
When test needs call for higher power and higher frequency, consider our t series microwave amplifier line 0. Traveling wave tube an overview sciencedirect topics. Output power will be taken from the helix in the conventional manner. The resonating electric fields in and out produce microwaves in the direction opposite to the electron beam. Mt 4500 multiband antenna mount travelling wave tube power amplifier for satellite uplink applications. In this video i did a teardown of an hp 493a microwave amplifier and took a look at whats inside the traveling wave tube. The transfer characteristic of a travelling wave tube amplifier the transfer characteristic is essentially linear, which permits the tube to be used to amplify ssbone of its great advantages in an amateur context. These amplifiers provide coverage for a wider range of highpower microwave test applications than any other brand of microwave amplifier on. Kuband travelling wave tube amplifier twta systems in rackmount and rugged outdoor antenna mounted configurations from 200 2000 watts covering frequencies from. To make construction of the tube rf output circuit simple, the collector and helix are grounded. Teardown of a microwave amplifier and a traveling wave tube. In a travelingwave tube the kinetic energy of electrons is transferred to the power of an electromagnetic wave rfsignal.
Quarterwave stocks some twts and amplifiers with power levels ranging from 40 watts to 2 kilowatts and frequencies from 1ghz to 18ghz. Electron transittime and exit velocity in linear beam. The large signal behavior of linear beam travelling wave amplifier is presented in this paper. What links here related changes upload file special pages permanent link page information wikidata item cite this page. Rf input is sent to one end of the helix and the output is drawn from the other end of the helix. As we know amplifier is a device which increases current, voltage or power of signal provided as its input. With other twts our standard amplifiers are capable of power levels from 10 watts to 50 kilowatts and frequencies from 1. This page was split from our microwave tube page and we added some content and photos thanks to terry cisco. An appendix offers a technical explanation of how the twt operates. The twt is designed with helix delay structure to slow the travelling wave down to or below the speed to the electrons in the beam. Mar 25, 2018 teardown of a microwave amplifier and a traveling wave tube kerry wong. The travelingwave tube is a critical subsystem for satellite data transmission. Extending the life of a traveling wave tube handling of.
As the input is increased, however, the amplifier saturates. Reinaldo perez, in wireless communications design handbook, 1998. Cpi satcom kuband outdoor travelling wave tube amplifiers twta is available to buy in increments of 1. Physical construction and functional describing of traveling wave tubes. The results indicate that the presence of the beam in the helix causes the normal mode to break up into three modes with different propagation characteristics. The da consists of a pair of transmission lines with characteristic impedances of z 0 independently connecting the inputs and outputs of several active devices. Twt has become the microwave amplifier of choice for many. Travelling wave tube twt mainly determining the rf performance and the integrated electronic power conditioner epc, designed and manufactured by bosch, for power matching of the dc and bus interfaces. High efficiency travelingwave tube power amplifier for. Traveling wave tube development i for a serrodyne reentrant. September 17, 2017 september 12, 2018 engineeering projects. Mt4500 multiband antenna mount travelling wave tube power. The travelling wave tube can be used for wideband rf amplifier designs where even now it performs well against devices using newer technologies. It is the result of an unidimensional timedomain code for simulating the twt behavior.
The twt was invented by rudolf kompfner in 1942 in england, for this reason he. Xband, outdoor traveling wave tube amplifiers twtas satcom. Investigations included the upper limit of serrodyning, optimum modulation methods and the. Travelling wave tube amplifiers twtas for space applications. The problem of a helixtype travelingwave amplifier tube, under certain simplifying assumptions, is solved as a boundaryvalue problem. Custom twtas and oem twta modules are also available. Cpi satcom kuband outdoor travelling wave tube amplifiers. High power kuband travelling wave tube amplifiers twta. Full qualification of the modulator will be achieved in the beginning of 2018. The travellingwave tube twt is a device wherein an electron beam interacts with a. Development of a 220 ghz 50 w sheet beam travelling wave tube.
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 passes down the tube. It is one of the important microwave tubes mainly used for wide bandwidth, high gain, low noise and moderate peak and average power requirement. Category twta, sspa, gan, hpa, cband, kuband, dbsband, sband, kaband, xband, qband, amplifier, satellite communications equipment. Highefficiency kband space travelingwave tube amplifier for nearearth high data rate communications rainee n. The converter is based on zerovoltage switching and zerocurrent. The electron transit time and the electron exit velocity in a dielectric supported helix traveling wave tube amplifiers twtaare derived by solving the nonhomogeneous boundary value problem. Jan 20, 2015 traveling wave tubes twts are widely used in the radar and communications system as rf power amplifiers. The twt belongs to a category of linear beam tubes, such as the klystron, in which the radio wave is amplified by. The invention further relates to a method for providing travellingwave amplification and the use of such a travellingwave amplifier or method. The invention relates to a travellingwave amplifier comprising two transmission lines, and at least two amplifiers. Kaband, outdoor traveling wave tube amplifiers twtas.
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