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A traveling wave tube (TWT) is an electronic device used to produce high-power radio frequency signals.
The TWT was invented by Rudolf Kompfner in a British radar lab during World War II, and refined by Kompfner and John Pierce at Bell Labs. Both of them have written books on the device. In 1994, A.S. Gilmour wrote a modern TWT book which is widely used by U.S. TWT engineers today, and research publications about TWTs are frequently published by the IEEE.
TWTs are commonly used as amplifiers in satellite transponders.
http://en.wikipedia.org/wiki/Traveling_wave_tube
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Haeff
Lindenblad
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Kompfner
Pierce
http://scholar.lib.vt.edu/theses/available/etd-11242003-123529/unrestricted/Barts_etd_CH2.pdf
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Rudolf Kompfner (1909 – 1977) was an Austrian-born engineer and physicist, best known as the inventor of the traveling wave tube (TWT).
John Robinson Pierce (March 27, 1910 – April 2, 2002), was an American engineer and author. He worked extensively in the fields of radio communication, computer music, and science fiction.
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John Robinson Pierce wrote on electronics and information theory, and developed jointly the concept of Pulse code modulation (PCM) with his Bell Labs colleagues Barney Oliver and Claude Shannon. He supervised the Bell Labs team which invented the transistor, and at the request of one of them, Walter Brattain, coined the term transistor.
Pierce's early work at Bell Labs was on vacuum tubes of all sorts. During World War II he discovered the work of Rudolf Kompfner in a British radar lab, where he had invented the traveling-wave tube. Pierce worked out the math for this broadband amplifier device, and wrote a book about it, after hiring Kompfner for Bell Labs. He later recounted that " Rudy Kompfner invented the traveling-wave tube, but I discovered it .“ He did significant research into satellites, including an important leadership role (as vice President of Bell Laboratories for Research) in the development of the first commercial communications satellite, Telstar 1.
http://en.wikipedia.org/wiki/John_R._Pierce
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BĖGANČIOSIOS BANGOS LEMPOS • Galingi plačiajuosčiai MB virpesių stiprintuvai • Stiprinimą lemia sklindančios lėtinimo sistema elektromagnetinės bangos ir elektronų pluošto sąveika
Turinys 1. Bėgančiosios bangos lempos sandara ir veiksena 2. Bėgančiosios bangos lempos teorija 2.1. Konvekcinės srovės kintamoji dedamoji 2.2. Elektrinio lauko išilginė dedamoji 2.3. Lempoje sklindančios bangos 2.4. Stiprinimo koeficientas 3. Bėgančiosios bangos lempų lėtinimo sistemos 4. Bėgančiosios bangos lempų savybės ir taikymas
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Cutaway view of a TWT. (1) Electron gun; (2) RF input; (3) Magnets; (4) Attenuator; (5) Helix coil; (6) RF output; (7) Vacuum tube; (8) Collector.
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http://cache.eb.com/eb/image?id=206
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http://ite.gmu.edu/~omega/images/dtwt_1.jpg
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Bėgančiosios bangos lempos sandara 1 2 3 4 u 5 u 6 u
vf Ez u u u u u u c u u c u u u u u u u u u VGTU EF ESK [email protected] e e 2008 12 Bėgančiosios bangos lempos teorija c u u u γ jωt−γ z γ = α + β E z = E zm v = v + v ωt−γ z ρ = ρ + ρ ωt−γ z ωt−γ z m J = J + J u c u u u u u u u c u u u u u u u u c VGTU EF ESK [email protected] e e 2008 13 Konvekcinės srovės kintamoji dedamoji c u u u u u Ez J ρv J = ρ v + v ρ u (m v t = − E z ) u Ez u c J u Ez u c u I =f Ez VGTU EF ESK [email protected] e e 2008 14 c v = v + v ω t−γ z ρ = ρ + ρ ω t−γ z J = J + J ωt−γ z ωt−γ z γ = α + β E z = E z ωt−γ z J = ρv J ≅ ρ v + (ρ v + v ρ ) J = ρ v + v ρ v v ∂v ∂v z v << v z t ≅ v m = − E z = + t t ∂t ∂ z t v ∂v ∂v ωt−γ z ≅ + v = ( ω − γv )v t ∂t ∂ z E ω t−γ z ω t−γ z v = − z m( ω − γv )v = − E z m ω −γv ∂J ∂ρ γ = − ρ = J ∂ z ∂t ω VGTU EF ESK [email protected] e e 2008 15 c E γ J = ρ v + v ρ v = − z ρ = J m ω − γv ω ρ E γ ωρ E z J = − z J = − + v J m ω −γv ω m ω −γv ρ v = J mv = U β J J = − E z β = ω v U β − γ I β I = − E z U β −γ VGTU EF ESK [email protected] e e 2008 16 Elektrinio lauko išilginė dedamoji u u c u u u c u u Ez u u c u u z c z u u u u u u u u u Ez =f I VGTU EF ESK [email protected] e e 2008 17 u U = − X I z X = ω L B = ω C I = − BU z + I U I I = − X I = − BU + z z z I = I ωt −γ z γ I = U γU = X I X γ I = BU + γ I γ + BX U = γ X I I = γ + BX U = γ = BX = ω L C U X ωL L = = = = Z I γ C ω L C VGTU EF ESK [email protected] e e 2008 18 u γ + BX U = γ X I γ = BX X = − γ Z γ γ Z γ γ R U = I U = I γ − γ γ − γ ∂U U = U ωt −γ z E = − = γU E z = γU z ∂z γ γ R E z = − I γ − γ VGTU EF ESK [email protected] e e 2008 19 Bėgančiosios bangos lempoje sklindančios bangos I β I = − E z U β −γ γ γ R E z = − I γ − γ I =f Ez Ez =f I γ γ γ δ VGTU EF ESK [email protected] e e 2008 20 γ γ δ R I γ = ω L C δ ≅ C β β = ω v C = U C γ = γ + Cβ − + = + β − Cβ = β +α C β = + β v < v α < α = − Cβ C VGTU EF ESK [email protected] e e 2008 21 Stiprinimo koeficientas E l = E Cβ l z z E l K = z = Cβ l = Cβ l Ez ω ω c β = β = = = k = v c v λ λ l K ≅ C = CN N = l λ λ K CN - c C=f R , I , U N=l / λ VGTU EF ESK [email protected] e e 2008 23 u u c u u u u c u u c u u z c u u u N R u u c u u c u c u u u u VGTU EF ESK [email protected] e e 2008 24 u c u K CN – –S u u u c c u u u ∆F f u c u u u c u η z z u VGTU EF ESK [email protected] e e 2008 25 TWTs are mainly classified into two types, helix TWTs and coupled- cavity TWTs, according to the RF circuit structure. Helix TWTs are limited in peak RF power by the current handling (and therefore thickness) of the helix wire. As power level increases, the wire can overheat and cause the helix geometry to warp. Wire thickness can be increased to improve matters, but if the wire is too thick it becomes impossible to obtain the required helix pitch for proper operation. Typically helix TWTs achieve less than 2.5 kW output power. The coupled-cavity TWT overcomes this limit by replacing the helix with a series of coupled cavities arranged axially along the beam. Conceptually, this structure provides a helical waveguide and hence amplification can occur via velocity modulation. A coupled-cavity TWT can achieve 15 kW output power. http://en.wikipedia.org/wiki/Traveling_wave_tube VGTU EF ESK [email protected] e e 2008 26 VGTU EF ESK [email protected] e e 2008 27 u u u u VGTU EF ESK [email protected] e e 2008 28 e e e e traveling wave tube amplifier. 21" long, 2" diameter. "N" connector in / out. • 6.3v heater, 152 amps • 1063v cathode, 47.2 ma • 41.2v grid, 5.2 ma • 34.7 dB noise figure • VSWR < 2:1 in / outputs • 1208 - 1450 MHz to 55 dB small signal gain Includes data sheets. New in box, Mil-Surplus. VGTU EF ESK [email protected] e e 2008 29 e e e e traveling wave tube has WR-229 (5cm x 8cm outside) flanges. These are used, removed from equipment. Nomenclature not available. 17" long. VGTU EF ESK [email protected] e e 2008 30 Packaged high-power, high-efficiency Ka-band TWT; L-3 Communications Electron Technologies, Inc., Model 999HA. VGTU EF ESK [email protected] e e 2008 31 A new traveling-wave tube amplifier (TWTA) has been designed for EMC testing. Model 1000TP1G3 is a 1000/500-W pulse amplifier designed to simulate the effect of a car driving through a beam of radar. www.ce-mag.com/archive/05/07/resources.html VGTU EF ESK [email protected] e e 2008 32 …examples are military traveling wave tube TWT power supplies. www.fivestarassoc.com/mil.html VGTU EF ESK [email protected] e e 2008 33 c c http://www.aerospace-technology.com/projects/contour/contour2.html VGTU EF ESK [email protected] e e 2008 34 Bėgančiosios bangos lempos. Užduotys U I f z R Ω c u VGTU EF ESK [email protected] e e 2008 34 7. Raskite penktojo laipsnio šaknies iš j reikšmes. +n⋅ = +n = e ϕ ≅ VGTU EF ESK [email protected] e e 2008 34 8. Bėgančiosios bangos lempos U = 2 kV, I = 4 mA, f = 8 GHz, R = 20 Ω. Raskime lėtinimo sistemos lėtinimo koeficientą. Koks turi būti lėtinimo sistemos ilgis, kad galios stiprinimas būtų 30 dB? k ≅ = U R I C = = ≅ K CN - U N = ≅ c λ − λ = λ = = ≅ ⋅ f k l = Nλ = ≅ VGTU EF ESK [email protected]