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