The primary objective of the 914h program was to design and build a. Overmoded twt project goals overmoded design can push to high power at high frequency our goal is to experimentally validate a 94 ghz overmoded coupled cavity twt with 30 db of gain 300 w peak power low magnetic field 2. The particleincell simulation takes into account the space charge field, the beam. Most notably, a coupled cavity twt developed at varian, inc. Other articles where coupledcavity travelingwave tube is discussed. Return product form for coupled cavity traveling wave tubes. Coupled cavity slow wave structure coupled cavity twt the coupled cavity twt uses a slow wave structure of a series of cavities coupled to one another. The slowwave structure has been modeled and coldtest characteristics data were obtained. After 28 years of considerable research and development, two types of travelingwave tube twt circuits have captured the major portion of the production business. Most coupledcavity twts have a phase velocity taper toward the end of the output section to improve the efficiency andor bandwidth of the device. The pulse parameters and the stability regions of the steadystate solution relative to the cavity length detuning and other. A novel coupledcavity structure for highpower wideband millimeterwave twt, called sheetbeam coupledcavity, is proposed by simon j. Request pdf an overmoded wband coupledcavity twt a 94ghz overmoded travelingwave tube twt has been designed, fabricated, and successfully tested. For example, some embodiments provide a coupled cavity traveling wave tube including a plurality of core segments arranged in spacedapart fashion to form an electron beam tunnel, a first longitudinal member adjacent the plurality of core segments alternately extending toward and receding from successive core.
A coupled cavity twt can achieve 60 kw output power. Coldtest characteristics including dispersion and coupling impedance of a coupledcavity slowwave structure for space twt working in millimeter band have been simulated by selfdesigned software. Osa coupled mode theory analysis of modesplitting in. L5652 coupled cavity traveling wave tube electron devices l3s l5652 xband dualmode coupled cavity traveling wave tube provides power levels up to 40 kw peak and 1,400 w average in the high mode, and 4. This highefficiency cc twt is designed for use in satellite communication amplifiers custom configurations are also available. Osa theory of nonlinear coupledcavity mode locking. Global traveling wave tubes twt market by product type helix twt, coupled cavity twt and by endusersapplication radar systems, communication satellite global market share, forecast data, indepth analysis, and detailed overview, and forecast, 20 2026. It is meaningful to point out that mode splitting can also occur in a single tw cavity system by introducing structural perturbations on the cavity 17, 18. Jan 05, 1999 the present invention is a coupled cavity gyrotrontravelingwavetube amplifier which produces highly efficient, broad band millimeter wave radiation. Analysis of rf oscillations in coupledcavity twt at millimetre wave.
Coupledcavity travelingwave tube electronics britannica. The objective was to obtain 4 kw, cw with 1% bandwidth at 12. The vta6430a series are 500w cw coupled cavity twt s covering 27. The beamwave interaction in a kaband relativistic coupled. They are quite old books but they will give you a start in the area of cross field. The tube has a higher efficiency than most coupled cavity twts of comparable bandwidth.
Request pdf design of wband coupledcavity twt by liga fabrication the laddercore structure of coupledcavity twts with dual inline coupling has attracted interest in a highpower mmwave. Global traveling wave tubes twt market by product type. Helix and coupledcavity travelingwave tubes ieee journals. Phase linearity of the 914h coupledcavity traveling wave tube frank kavanagh analex corporation 3001 aerospace parkway brook park, ohio 44142 summary tests of phase deviation from linearity were made on two 914h coupledcavity traveling wave tubes twt. Pulsed coupled cavity twt, vts5753 datasheet, vts5753 circuit, vts5753 data sheet. The eigenmode calculations and linear smallsignal analyses by larsen et al. Design of helix slowwave structures for high efficiency twts core. Calculation of coupledcavity twt performance ieee xplore. Helix and coupledcavity travelingwave tubes abstract. The rf fields calculated by teslacc inside the beam tunnel of the cctwt agree well with the fields calculated by 3d electromagnetic code analyst 3. A novel coupled cavity structure for highpower wideband millimeterwave twt, called sheetbeam coupled cavity, is proposed by simon j.
By the method of the eigen mode expansion, a full threedimensional 3d model has been developed that can be used to investigate the beamwave interaction in a highpower, kaband relativistic coupled cavity travelingwave tube twt. Results of the effects of sever position on saturated efficiency, tube length and bandwidth are presented. It is meaningful to point out that mode splitting can also occur in a single twcavity system by introducing structural perturbations on the cavity 17, 18. Operation is similar to that of a klystron, except that coupled cavity twts are designed with attenuation between the slowwave structure instead of a drift tube. In addition to providing extremely reliable high power, these coupledcavity amplifiers performance is second to. The feature that distinguishes the coupled cavity twt from other types is the sws, which consists of a series of cavities, is coupled by. The design and analysis of a highpower wideband sheetbeam coupledcavity travelingwave tube operating at vband is presented. In the tube studied by us, a sever in the interaction section is used to restrain the oscillation of rf electromagnetic fields between the input and output end. This device has a nonintercepting grid pulsed and single stage depressed collector to achieve 4.
Analysis of a coupledcavity slow wave structure for a twt nopr. Vtc5760b datasheet11 pages cpi vtc5760b pulsed coupled. The interaction circuit employs threeslot doubly periodic staggeredladder coupledcavity slowwave structure, and a 5. Travelingwave tube wikimili, the best wikipedia reader. Pdf in order to make millimeterwave sources practical, improved fabrication methods are required. The dispersion simulation result is obtained more consistent with experiment data than the method that ignoring effect of the conducting barrel. Design of phase velocity tapers in coupledcavity twts. Operation is similar to that of a klystron, except that coupledcavity twts are designed with attenuation between the slowwave structure instead of a drift tube. Coupledcavity traveling wave tube twt amplifiers are reliable and compact vacuum devices at high frequencies with a variety of applications. The resonant cavities are coupled together with a transmission line. Various embodiments of a coupled cavity traveling wave tube are disclosed herein. Sw cavity system can perform the same functions as an undercoupled tw cavity system. This paper describes an approach of designing a coupledcavity slow wave structure ccsws for a high power traveling wave tube twt using hfss code. Coupled cavity twts microwave power products division.
Coupled cavity traveling wave tubes operating instructions. Tigner laboratory of nuclear studies, cornell university ithaca,new york,14853 summary a parallel coupled rf cavity structure which provides favorable solutions to all of the require. Pdf analysis of a coupledcavity slow wave structure for a twt. The coupled cavity twt uses a slow wave structure of a series of cavities coupled to one another. Coupledcavity twt amplifiers deliver extremely high power.
The electron beam shown in figure 9 as red beam is velocity modulated by an rf input signal at the first resonant. The paper describes investigations carried out using a onedimensional largesignal computer model into the best choice of sever position in coupled cavity twts. Nov 10, 2007 coldtest characteristics including dispersion and coupling impedance of a coupled cavity slowwave structure for space twt working in millimeter band have been simulated by selfdesigned software. May 31, 2012 for example, some embodiments provide a coupled cavity traveling wave tube including a plurality of core segments arranged in spacedapart fashion to form an electron beam tunnel, a first longitudinal member adjacent the plurality of core segments alternately extending toward and receding from successive core segments, and a second longitudinal. The present invention comprises an electron gun, a double ridged coupled cavity interaction circuit and a beam collector. The rf fields calculated by teslacc inside the beam tunnel of the cc twt agree well with the fields calculated by 3d electromagnetic code analyst 3 for wide range of frequencies. A 94 ghz overmoded traveling wave tube twt amplifier. Design of wband coupledcavity twt by liga fabrication. Coupledcavity travelingwave tube cctwt promises high peak power and moderate bandwidth at millimeterwave band. The tube is modeleji as a sequence of interaction gaps and tunnels, with cavities associ. Request pdf design of wband coupledcavity twt by liga fabrication the laddercore structure of coupled cavity twts with dual inline coupling has attracted interest in a highpower mmwave. The interaction circuit employs threeslot doubly periodic staggeredladder coupled cavity slowwave structure, and a 5. More recently, a complex integralpolepieceferruleless coupled cavity foldedwaveguide circuit built by l3 communications, inc.
However, advances in wband twt design have been limited since that achievement. A coupledcavity twt can achieve 60 kw output power. The electron beam shown in figure 9 as red beam is velocity modulated by an rf input signal at the first resonant cavity. Cpi, alldatasheet, datasheet, datasheet search site for electronic components and. Sw cavity system can perform the same functions as an under coupled tw cavity system. The slowwave structure gives the twt its wide bandwidth. By the method of the eigen mode expansion, a full threedimensional 3d model has been developed that can be used to investigate the beamwave interaction in a highpower, kaband relativistic coupledcavity travelingwave tube twt. The modelocking dynamics of coupledcavity modelocked ccm lasers with a kerr medium in the external or the main cavity or both are analyzed without the approximation of weak external feedback.
We analyze transmission characteristics of two coupled identical cavities, of either standingwave sw or travelingwave tw type, based on temporal coupled mode theory. The coupledcavity twt uses a slow wave structure of a series of cavities coupled to one another. Analysis of a coupledcavity slow wave structure for a twt. The effects of direct and indirect couplings, if coexisting in one system, can offset each other. Analysis of coupledcavity slowwave structures for space twt. The present invention is a coupled cavity gyrotrontravelingwavetube amplifier which produces highly efficient, broad band millimeter wave radiation. In this paper, the software coldtest simulation method to obtain rf dispersion, interaction impedance by mafia software is discussed considering effect of the conducting barrel in the millimeterwave twt. The paper describes investigations carried out using a onedimensional largesignal computer model into the best choice of sever position in coupledcavity twts. More recently, a complex integralpolepieceferrulelesscoupledcavity foldedwaveguide circuit built by l3 communications, inc. The design and analysis of a highpower wideband sheetbeam coupled cavity travelingwave tube operating at vband is presented. The pulse parameters and the stability regions of the steadystate solution relative to the cavitylength detuning and other. The helix twt, however, has no particular bandwidth limitations, and, for all practical purposes, an octave bandwidth 100 percent is attainable.
One tube had a voltage standing wave ratio vswr of 2. A travelling wave tube having a coupled cavity slow wave structure is provided with velocity tapering to slow the speed of travel of an applied radio frequency wave at the output end of the tube so that it is maintained substantially in step with the decreasing velocity of the electron beam. Pulsed products xband, coupled cavity twts microwave. The efficiency of travellingwave tubes twts operated under nonlinear conditions is usually enhanced by adjusting the phase velocity of the slowwave circuit towards the output end of the tube. Phase linearity of the 914h coupled cavity traveling wave tube frank kavanagh analex corporation 3001 aerospace parkway brook park, ohio 44142 summary tests of phase deviation from linearity were made on two 914h coupled cavity traveling wave tubes twt. The vta6430a series are 500w cw coupled cavity twts covering 27. The twt belongs to a category of linear beam tubes, such as the klystron, coupled cavity twt in which the radio wave interacts with the beam in a. It has a dual mode gun that employs two concentricring control grids in addition to a shadow. Coupledcavity twt interaction is similar to helix twt interaction in one respect, that is, power flows along the circuit. May 27, 2019 global traveling wave tubes twt market by product type helix twt, coupled cavity twt and by endusersapplication radar systems, communication satellite global market share, forecast data, indepth analysis, and detailed overview, and forecast, 20 2026. Coupled mode theory analysis of modesplitting in coupled. Helix and coupled cavity travelingwave tubes abstract. The modelocking dynamics of coupled cavity modelocked ccm lasers with a kerr medium in the external or the main cavity or both are analyzed without the approximation of weak external feedback.
Abstracttwts for space applications commonly have a helix pitch profile which. Coupledcavity slow wave structure coupledcavity twt the coupledcavity twt uses a slow wave structure of a series of cavities coupled to one another. Determination of sever positions in coupledcavity twts. Pdf novel coupledcavity twt structure using twostep liga. The higher accuracy is needed in narrowband tubes, as well as in some mmw tubes of moderate bandwidth. Coupled cavity gyrotrontravelingwavetube amplifier choi. Software cold test simulation of coupled cavity slowwave. For example, some embodiments provide a coupled cavity traveling wave tube including a plurality of core segments arranged in spacedapart fashion to form an electron beam tunnel, a first longitudinal member adjacent the plurality of core segments alternately extending toward and receding from successive core segments, and a second longitudinal. Mode splitting is observed for both directly cavitycavity and indirectly cavitywaveguidecavity coupled cavity systems. Pdf this paper describes an approach of designing a coupledcavity slow wave structure ccsws for a high power traveling wave tube twt using hfss. L5906 coupled cavity traveling wave tube electron devices l3s l5906 coupled cavity twt provides a minimumpulsed power output of 50 kw over a frequency range of 9. Jb phase linearity of the 914h coupledcavity traveling. He is leading research and development on ultra high power microwave sources. To read and print pdf files, download adobe acrobat reader.
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