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Classical Electrodynamics Applied in Modern Technology

Classical Electrodynamics Applied in Modern Technology. 1. Properties of Nano- Metal Films. Günter Nimtz Physics Department, University of Cologne. 2 . Anechoic EMC Chambers: Pyramidal Absorber Absorption by Anechoic Traps: Reflecting Curtains

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Classical Electrodynamics Applied in Modern Technology

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  1. ClassicalElectrodynamics Applied in Modern Technology • 1. Properties of Nano-Metal Films Günter Nimtz Physics Department, University of Cologne • 2. AnechoicEMC Chambers: Pyramidal Absorber • Absorption byAnechoic Traps: ReflectingCurtains • 4. Ferrite Tile Absorber……….Hybrid Absorbers • Rain SensingWipers: Frustrated Total Internal Reflection = Tunneling

  2. Free carrierEM interaction : Drude (1900), Hagen & Rubens (1902) Nano metalfilms(gravimetricaldetermination !) Infraredstudies on Absorption, ReflectionandTransmission: A + R + T = 1 Murmann; Barnes; Czerny; Woltersdorff (1929 – 1934)

  3. R A T R + T + A = 1 of Nano-Film Resistance Angle ofincidence =   = 900 • > d T = {1 + Zo/(2 Z)}-2 ; Zovacuumimpedance Z =/d sheetresistance d film thickness TM = 450 EM  = 450

  4. Howtoget a hugemetalcavitybehavelikefreespacewith : ZO = 377 Ω, i.e. nostandingwavepatterns? Installabsorbersatthewalls! EM anechoicchambers Installabsorbersatthewalls! Metalwalls

  5. EM AnechoicChamber

  6. Nano-Metal-Film, a 10 nmmetal film vapordepositedon 10 µm polyethylenefilm

  7. Sheet ResistanceZisRelevant for Wave Propagation if» d : Z= 1/( d) d d  = conductivity d = film thickness  = wavelength Foam≈10-7 Nano-MetalFilm (≈ 0.1 S/m) (≈ 106S/m)   2.4 m International Patents: G. NimtzandA. Enders (1998)

  8. Standing Waves in Front oftheMetal Wall Variation ofimpedancewithpositionalongtheline(Smith Diagram) Z AbsorbingPyramids: Absorption with Low Reflection  Z = 0 Foam E Nano-film E = electricfield

  9. Metal VacuumImpedance Z0 = 377 Ω E /4 Z = Ω ≈377 ΩShunt NoReflection The variationofimpedancewithpositionalongtheline (Smith Diagram)

  10. R A T R + T + A = 1 of Nano-Film Resistance Angle ofincidence =   = 900  > d Special Property : For 188 Ω: 0.25 + 0.25 + 0.5 = 1 TM = 450 EM  = 450

  11. NovelPrinciple, Device under Test: Absorption by Multiple Reflection e.g. 8 Reflections: R(total) = 0.258 - 48 dB; dB = 10 lg(P1/P2) Anechoictrap Transmitter nano-Metal Films Metal Wall NimtzandPanten, Ann. Phys. 19, 53 (2009); Pending Patents, G. Nimtz (2008)

  12. Curtainsofnano Films insteadofPyramids atonewall asshownnextfigure

  13. EM Anechoic Chamber

  14. In small Chambers: Ferrite TileswithZF ≈ Z06.3 mm; 30 MHz – 300 MHz (< -20 dB, regulation) Hybrid Absorber: Pyramidal Absorber + Ferrite Tile (30 – 18 000 MHZ) ZF = Z0 µr/r = Z0 ! Reflection R: R = (n1 – n2)/(n1 + n2) = (ZF – Z0)/ZF + Z0) Metal Wall

  15. Ferrite tiles TDK (Ni-Cu-Zn) :

  16. Rain sensingwiper: frustrated total reflection

  17. glass n1 > n2 air Total Reflectionif: sin  n2/n1 tot = arc sin(n2/n1) Frustration :   tot  ß

  18. The double prisms: frustratedtotal internalreflection The analog ofquantummechanicaltunneling Sommerfeld (1954)

  19. Front windshield Rain SensingWipers: Frustrated total reflexion Rain representsthesecondprism LED Rain……. Prism Receiver

  20. SummingUp : • Nano-Metal Film Absorbers areBroad Band Absorbers, Superior toCarbonizedFoam Absorber • Incombustible. Non-Toxic.NoHazardousWaste • Nano-Metal Film Absorbers on Dutysince 1995 • Ferrite Tiles, verythin but expensive (30-400 MHz) • Frustrated total internalreflectionas rain sensingcardevice. • Double Prisms:Newton 1700, BOSE 1900, Sommerfeld 1954

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