Lowvoltage operation of millimeterwave folded waveguide travelingwave tube twt was investigated using a 12 kv linear electron beam. Discussion of the characteristics of travelingwave tube amplifiers and several applications. What makes the travelling wave tube twt able to amplify. Twt amplifiers twta traveling wave tube amplifiers. High power kuband travelling wave tube amplifiers twta. Highefficiency kband space travelingwave tube amplifier for nearearth high data rate communications rainee n. Description of the travelling wave tube amplifier the twta is a very complex equipment and a key element of a satellite transponder. Electrons are fired from cathode and received from collectors. The traveling wave tube can be used as a medium or high power microwave, amplifier. Design tradeoffs and optimization guidelines for maximum operation frequency, gain and minimum noise are illustrated. As we know amplifier is a device which increases current, voltage or power of signal provided as its input. 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. Highly linear eband traveling wave tube amplifier sbir. Troubleshooting a traveling wave tube amplifier september 17, 2017 september 12, 2018 engineeering projects before continuing about troubleshooting of traveling wave tube amplifier we have some initial considerations include.
Investigations included the upper limit of serrodyning, optimum modulation methods and the. The problem of a helixtype travelingwave amplifier tube, under certain simplifying assumptions, is solved as a boundaryvalue problem. Travelingwave amplifier article about travelingwave. A millimeterwave these factors can make a communication system impractical to implement, particularly for powerconsumptionsensitive applications such as satcom at millimeterwave the most efficient form of amplification is normally a twt.
Download it once and read it on your kindle device, pc, phones or tablets. The operation of the da can perhaps be most easily understood when explained in terms of the travelingwave tube amplifier twta. The travellingwave tube twt is a device wherein an electron beam interacts with a. 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. Teardown of a microwave amplifier and a traveling wave tube. With other twts our standard amplifiers are capable of power levels from 10 watts to 50 kilowatts and frequencies from 1. Todd nasa glenn research center, 2 brookpark road, cleveland, oh 445, usa. On reason of the special lownoise characteristic often they are in use as an active rf amplifier element in receivers additional. Therefore, this discussion applies to both sspa and twtas.
Absolute instability near the band edge of travelingwave. Quarterwave high power traveling wave tube amplifiers twta. The main attraction of these devices is their very high gain 3060 db, linear characteristics and 12 octave bandwidth. Cpi satcom kuband outdoor travelling wave tube amplifiers twta is available to buy in increments of 1 frequencies from. Teardown of a microwave amplifier and a traveling wave tube kerry wong. Millimeterwave gyrotron travelingwave tube amplifiers. 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. Other articles where travelingwave tube is discussed. Travelling wave tube twt is an electronic vacuum microwave device, which is. Traveling wave tube development i for a serrodyne reentrant. Twtas traveling wave tube amplifiers are an alternative to the. Traveling wave tube amplifiers surplus sales of nebraska. Millimeter wave gyrotron traveling wave tube amplifiers kindle edition by du, chaohai, liu, pukun. A big part of the keane sound is us feeding pianos and synths through weird chains of effects.
The new wavering helical wrh slowwave structure for. The results show that in the special frequency range the output power and gain are greater. A twt is capable of gains from 40 to 70 db with bandwidths exceeding two octaves. Jackson abstract the problem of a helixtype traveling wave amplifier tube, under certain simplifying assumptions, is solved as a boundaryvalue problem. Solid state amplifiers sspa used mostly at sband also exhibit performance characteristics similar to twtas.
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. High efficiency is required in order to optimize rf output power and heat dissipation. Nov 29, 2010 traveling wave tubetraveling wave tube is an electric vacuum device, intended for generation and amplification of microwave oscillations. Travelling wave tube travelling wave tubes are broadband microwave devices which have. Twt amplifiers ifis twta traveling wave tube amplifiers cw continuous waveform, twt gridded pulsecw and twt pulse amplifier product lines fill the requirements for all your high frequency, highpower microwave testing applications.
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. This chapter provides the basic description of the twta structure and. 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. Microwave tube, a key element in the modern world of communication ernst bosch thales electronic system gmbh, ulm, germany ernst. The series a600 traveling wave tube amplifiers, hereafter referred to as the a600, are selfcontainedinstruments suitable for bench or rack use. As military and commercial data links become more sophisticated, complex modulations such as quadrature amplitude modulation qam and others are desired for a variety of. 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. Millimeterwave gyrotron travelingwave tube amplifiers kindle edition by du, chaohai, liu, pukun. Travellingwave tubes chapter 14 microwave and rf vacuum.
The twt was invented by rudolf kompfner in 1942 in england, for this reason he appears in our microwave hall of fame. At a supply voltage of 3 v and a supply current of 21 ma, a minimum gain of 5. High power traveling wave tube amplifier and power supply. This chapter provides the basic description of the twta structure and its various components. Ifi designs, manufactures and distributes a full line of twt traveling wave tube amplifiers for both the commercial. Traveling wave tube amplifier 1208 1450 mhz to 55 db small signal gain. 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.
Ifi designs, manufactures and distributes a full line of twt traveling wave tube amplifiers for both the commercial and military markets. The travelling wave tube can be used for wideband rf amplifier designs where even now it performs well against devices using newer technologies. 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. They feature low harmonics, low phase noise, excellent amplitude and phase stabilities, local andor remote operation, extensive bit and status monitoring, and much more. An appendix offers a technical explanation of how the twt operates. To date, both the negative feedback and travelingwave amplifier concepts have been limited to broadband amplifier designs only. 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. A bandwidth of 1 octave is one in which the upper frequency is twice the lower frequency. These amplifiers provide coverage for a wider range of highpower microwave test applications than any other brand of microwave amplifier on. The rf performance characteristics such as high gain, gain flatness, low phase distortion and high linearity shall be combined with straight forward me. The traveling wave tube is a form of thermionic valve or tube that is used for high power microwave amplifier designs.
At present, traveling wave amplifiers are employed extensively in the design of broadband amplifiers operating over the bandwidth of 2 to 18 ghz. Traveling wave tube an overview sciencedirect topics. These traveling wave tube amplifiers twtas offer power levels from 20 w to 1 kw cw and up to 70 kw pulsed. This page was split from our microwave tube page and we added some content and photos thanks to terry cisco.
For these purposes the device uses the interaction between. Travelling wave tube amplifier vacuum tube free 30. A 94 ghz overmoded traveling wave tube twt amplifier. As the input is increased, however, the amplifier saturates. Twt is used in microwave receivers as a low noise rf amplifier. The panel serves as a mounting for the controls and monitoring meters. In this video i did a teardown of an hp 493a microwave amplifier and took a look at whats inside the traveling wave tube. An electron gun focusses an electron beam with the velocity of light. When test needs call for higher power and higher frequency, consider our t series microwave amplifier line 0. Travelling wave tube amplifier twta satcom systems travelling wave tube amplifier twta we offer the widest range and best performance twtas in the world, extremely aggressive pricing structure.
The other difference between terms are provided here. To date, both the negative feedback and traveling wave amplifier concepts have been limited to broadband amplifier designs only. 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. Rf input is sent to one end of the helix and the output is drawn from the other end of the helix. A gyrotrontravelingwave tube amplifier experiment with a ceramic loaded interaction region article pdf available in ieee transactions on plasma science 303. Twta abbreviation stands for traveling wave tube amplifier. This page on twta vs sspa provides difference between twta and sspa. 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. At present, travelingwave amplifiers are employed extensively in the design of broadband amplifiers operating over the bandwidth of 2 to 18 ghz. Heater and cathode act as electron gun, and they are on the side rf input. In this paper, the new slowwave structure called wavering helix to enhance the power of the traveling wave tubes is introduced. These are generally used to amplify microwave signals over broad bandwidths. Waves gtr3 gives us the ability to experiment with new sounds quickly and creatively. September 17, 2017 september 12, 2018 engineeering projects.
Mar 25, 2018 teardown of a microwave amplifier and a traveling wave tube kerry wong. The travelingwave tube can be used as a medium or high power microwave, amplifier. The a600 units are 220vac, 3phase powered and consist of a panel, a chassis, internal twt, frame, and covers. 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.
Millimeterwave gyrotron travelingwave tube amplifiers, du. 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. The problem of a helixtype travelingwave amplifier tube, under certain simplifying. Highefficiency kband space traveling wave tube amplifier for nearearth high data rate communications rainee n. The results indicate that the presence of the beam in the helix causes the normal mode to break up. Helix studies as mentioned in the last progress report, a largescale model of the helix used in the travelingwave tube was constructed. Pdf new model of a travellingwave tube researchgate. Twt amplifiers twta traveling wave tube amplifiers d. In the past few years, several radio amateurs have employed travelling wave tubes twts, colloquially known as twits, as microwave power amplifiers. Use features like bookmarks, note taking and highlighting while reading millimeterwave gyrotron travelingwave tube amplifiers. Custom twtas and oem twta modules are also available. Backward wave oscillation operated at second space harmonic. Kuband travelling wave tube amplifier twta systems in rackmount and rugged outdoor antenna mounted configurations from 200 2000 watts covering frequencies from. Nov 22, 20 new vacuum power amplifier demonstrated at 0.
Twt has become the microwave amplifier of choice for many. A travelingwave tube twt, pronounced twit or travelingwave tube amplifier twta. Ifis twta traveling wave tube amplifiers cw continuous waveform, twt gridded pulsecw and twt pulse amplifier product lines fill the requirements for all your high frequency, highpower microwave testing applications. High power traveling wave tube amplifiers twta, high. Wave tube amplifier the twta is a very complex equipment and a key element of a satellite transponder. A female connector is used on the input to mate with the male connector used on the output of new focus highspeed photodetectors. Pdf lowvoltage operation of kaband folded waveguide. The twt, because of its construction and working principle has enormous bandwidths and low noise. This paper will discuss the implementation of a wideband highgain gyro traveling wave tube amplifier design, with a measured peak output power of 78 kw, gain. The output of a klystron or an iot incorporates a resonant circuit so that it is effectively operating as a class b or c amplifier. Travellingwave tube twt is a wideband microwave amplifier. Broadband, ultralinear, extremely high frequency ehf.
Find traveling wave tube amplifiers related suppliers, manufacturers, products and specifications on globalspec a trusted source of traveling wave tube amplifiers information. Highefficiency kband space travelingwave tube amplifier. Quarterwave stocks some twts and amplifiers with power levels ranging from 40 watts to 2 kilowatts and frequencies from 1ghz to 18ghz. Pdf a gyrotrontravelingwave tube amplifier experiment. Helix studies as mentioned in the last progress report, a largescale model of the helix used in the travelingwave. Twta stands for travelling wave tube amplifier and sspa stands for solid state power amplifier. Modern devices and contemporary applications traveling wave tube twt is used as a microwave amplifier for radar. Refurbishment the amplifier research 200t4g8 is a self contained, forced air cooled, broadband traveling wave tube twt micro wave amplifier designed for applications where instantaneous bandwidth and high gain a. Traveling wave tube amplifiers are widely used in satellite applications to provide signal power amplification at high frequencies. The rf performance characteristics such as high gain, gain flatness, low phase distortion and high linearity shall be com. In this new structure, without increasing the length and radius of the helix, the wave motion path can be increased to radiofrequency wave in phase with the electron beam. 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.
Troubleshooting a traveling wave tube amplifier engineering. They take therefore a special position under the velocitymodulated tubes. Travelling wave tube amplifiers twtas for space applications. What is the abbreviation for traveling wave tube amplifier. Helix studies as mentioned in the last progress report, a largescale model of the helix used in the traveling wave tube was constructed. Cpi satcom kuband outdoor travelling wave tube amplifiers. Attenuators placed along the rf circuit prevent the reflected wave from. Kowalski mit plasma science and fusion center muri teleseminar december 5, 2014. The heated cathode at one end of the tube produces a beam of electrons and. Travelingwave tubetravelingwave tube is an electric vacuum device, intended for generation and amplification of microwave oscillations.
Before continuing about troubleshooting of traveling wave tube amplifier we have some initial considerations include. The model 1421 and 1422 broadband amplifiers are housed in a compact unit whose input and output connectors are wiltron kconnectors. The traveling wave tube amplifier twta together with the klystron are known as. The twt belongs to a category of linear beam tubes, such as the klystron, in which the radio wave is amplified by. Travelling wave tube is a cylindrical structure which contains an electron gun from a cathode tube. Use features like bookmarks, note taking and highlighting while reading millimeter wave gyrotron traveling wave tube amplifiers. 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. Discussion of the characteristics of traveling wave tube amplifiers and several applications. 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. Travelling wave tube amplifier vacuum tube free 30day.