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Nguyễn Công Phương Engineering Electromagnetics GuidedWaves & Radiation Contents I II III IV V VI VII VIII IX X XI XII XIII XIV XV Introduction Vector Analysis Coulomb’s Law & Electric Field Intensity Electric Flux Density, Gauss’ Law & Divergence Energy & Potential Current & Conductors Dielectrics & Capacitance Poisson’s & Laplace’s Equations The Steady Magnetic Field Magnetic Forces & Inductance Time – Varying Fields & Maxwell’s Equations Transmission Lines The Uniform Plane Wave Plane Wave Reflection & Dispersion GuidedWaves & Radiation GuidedWaves & Radiation - sites.google.com/site/ncpdhbkhn GuidedWaves & Radiation Transmission Line Fields Basic Waveguide Operation Plane Wave Analysis of the Parallel - Plate Waveguide Parallel - Plate Guide Analysis Using the Wave Equation Rectangular Waveguides Planar Dielectric Waveguides Optical Fiber Basic Antenna Principles GuidedWaves & Radiation - sites.google.com/site/ncpdhbkhn Transmission Line Fields (1) – + E E H H + Vs V0 − jβ z Esx ( z ) = = e d d I s V0 − jβ z H sy ( z ) = K sz = = e b bZ – + + ++ ++ + + –––– –– k + where Z0 = L / C ++ ++ + + –– –––– –– Vs ( z ) = V0e V I s ( z) = e − j β z Z0 I – I − jβ z → Pz = ∫ ∫ Re{E xs Hˆ ys }dxdy 0 V0 Vˆ0 = (bd ) d bZˆ b d V0 = = Re[Vs Iˆs ] 2Zˆ0 GuidedWaves & Radiation - sites.google.com/site/ncpdhbkhn Transmission Line Fields (2) C= t ε 'b d d σ σb G= C= ε' d L ≈ Lexternal = R= σ cδ b Conductor (σc) t Dielectric (σ, ε’, μ) b µd b L d µ Z0 = = C b ε' GuidedWaves & Radiation - sites.google.com/site/ncpdhbkhn Transmission Line Fields (3) 2πε ' C= ln(b / a) Dielectric (σ, ε’, μ) σ 2πσ G= C= ε' ln(b / a) µ b Lexternal = ln 2π a Rinternal Conductor (σc) a b c Cao tần 1 = , Rexternal = 2π aδσ c 2π bδσ c 1 1 R= + 2πδσ c a b Z0 = Lexternal = C 2π GuidedWaves & Radiation - sites.google.com/site/ncpdhbkhn µ b ln ε' a Transmission Line Fields (4) 2πε ' C= ln(b / a ) σ 2πσ G= C= ε' ln(b / a ) l Rinternal = = σ c S σ c (π a ) Rexternal = Dielectric (σ, ε’, μ) Conductor (σc) a b c Low frequency σ c [π ( c2 − b )] 1 + πσ c a c − b2 µ b 1 c2 c L= ln + + b − 3c + 2 ln 2 2π a 4(c − b ) b c −b R= GuidedWaves & Radiation - sites.google.com/site/ncpdhbkhn Transmission Line Fields (5) C= πε ' −1 cosh (d / 2a ) Lexternal G= ≈ πε ' ln(d / a ) (a ≪ d ) µ µ d −1 = cosh (d / a ) ≈ ln (a ≪ d ) π π a a Conductor (σc) Dielectric (σ, ε’, μ) a d High frequency σ πσ C= ε' cosh −1(d / a ) R= π aδσ c GuidedWaves & Radiation - sites.google.com/site/ncpdhbkhn Transmission Line Fields (5) C= G= L= R= πε ' cosh −1 (d / 2a ) πσ a Conductor (σc) Dielectric (σ, ε’, μ) d −1 cosh (d / 2a ) a Low frequency µ 1 −1 + cosh ( d / a ) π π a 2σ c GuidedWaves & Radiation - sites.google.com/site/ncpdhbkhn Dẫn sóng & xạ Transmission Line Fields Basic Waveguide Operation Plane Wave Analysis of the Parallel - Plate Waveguide Parallel - Plate Guide Analysis Using the Wave Equation Rectangular Waveguides Planar Dielectric Waveguides Optical Fiber Basic Antenna Principles GuidedWaves & Radiation - sites.google.com/site/ncpdhbkhn 10 Optical Fiber (9) Vc (11) = V 0,8 m =1, ℓ =1 = 2.405 → J ℓ −1(Vc ) = → V < Vc (11) = 2.405 0,6 → λ > λc = 0,4 2π a n12 − n22 2, 405 0,2 – 0,2 J ( βt ρ ) J1(βt ρ ) – 0,4 10 12 14 GuidedWaves & Radiation - sites.google.com/site/ncpdhbkhn 16 53 Dẫn sóng & xạ Transmission Line Fields Basic Waveguide Operation Plane Wave Analysis of the Parallel - Plate Waveguide Parallel - Plate Guide Analysis Using the Wave Equation Rectangular Waveguides Planar Dielectric Waveguides Optical Fiber Basic Antenna Principles GuidedWaves & Radiation - sites.google.com/site/ncpdhbkhn 54 z Basic Antenna Principles (1) I = I0 cos ωt A=∫ V µ [J ] µ[ I ]dL µ[ I ]d dv = ∫ = az 4π R 4π R 4π R R [I ] = I0 cos ω t − v d I µ I d − jω R /v → Azs = e 4π R y x → [ I s ] = I0e − jω R /v Azs z µ I 0d − jωr /v Ars = Azs cos θ A = cos e θ rs 4π R Aθ s = − Azs sin θ → A = − µ I 0d sin θ e − jωr /v A = ϕs θ s 4π R θ r GuidedWaves & Radiation - sites.google.com/site/ncpdhbkhn –Aθs Ars P(r, θ, φ) y 55 Basic Antenna Principles (2) µ I 0d cosθ e − jωr / v 4π R µI d Aθ s = − sin θ e− jωr /v 4π R Ars = Aϕ s = B s = µ H s = ∇× A s ∂ ( Aϕ sin θ ) ∂Aθ ∇ ×A = − r sin θ ∂θ ∂ϕ ∂Ar ∂(rAϕ ) ∂(rAθ ) ∂Ar a + − a + − r θ r sin θ ∂ϕ ∂r r ∂r ∂θ ∂ ∂Ars ( rAθ s ) − Hϕ s = → µ r ∂r µ r ∂θ H = H = θs rs → Hϕ s = aϕ I0d ω 1 sin θ e− jωr /v j + 4π vr r GuidedWaves & Radiation - sites.google.com/site/ncpdhbkhn 56 Basic Antenna Principles (3) I0 d ω sin θ e − jω r /v j + 4π vr r H rs = Hθ s = Hϕ s = ∂D ∇ ×H = → ∇ × H s = jωε Es ∂t ∂ ( Hϕ sin θ ) ∂Hθ ∇×H = − r sin θ ∂θ ∂ϕ Ers = → E = θ s ∂Hr ∂ ( rHϕ ) ∂ (rHθ ) ∂H r a + − a + − r θ r sin θ ∂ϕ ∂r r ∂r ∂θ ∂ ( Hϕ s sin θ ) jωε r sin θ ∂θ 1 1 ∂ − (rHϕ s ) jωε r ∂θ aϕ I0d − jω r /v cos θ e + Ers = 3 π jωε r ε vr → I0d 1 − jωr /v jω θ + + Eθ s = 4π sin e 3 jωε r ε v r ε vr GuidedWaves & Radiation - sites.google.com/site/ncpdhbkhn 57 Basic Antenna Principles (4) Hϕ s = I0 d ω sin θ e − jω r /v j + 4π vr r I0 d − jω r /v Ers = cos θ e + 3 2π jωε r ε vr Eθ s I 0d 1 − jωr / v jω = sin θ e + + 3 4π jωε r ε v r ε vr ω = 2π f , f λ = v, v = 1/ µε , η = µ /ε I d 2π Hϕ s = sin θ e − j 2π r/λ j + 2 4π λr r I dη − j 2π r /λ → Ers = cos θ e + 3 π π r j r E = I dη sin θ e − j 2π r/λ j 2π + + λ λ r r j 2π r θs π GuidedWaves & Radiation - sites.google.com/site/ncpdhbkhn 58 Basic Antenna Principles (5) I0d − j 2π r / λ 2π Hϕ s = sin θ e j + 2 4π λr r Ex: I 0d = 4π , θ = 90o , t = 0, f = 300 MHz, v = 3.108 m/s, λ = m 2π − j 2π r → Hϕ s = j + e r r 2π → Hϕ = + cos{[arctg(2π r ) − 2π r ]} r r cos( a − b) = cos a cos b + sin a sin b cos[arctg( x)] = 1/ + x → Hϕ = r (cos 2π r + 2π r sin 2π r ) GuidedWaves & Radiation - sites.google.com/site/ncpdhbkhn 59 Basic Antenna Principles (6) I0 d 2π sin θ e − j 2π r /λ j + 2 4π λr r Ex I 0d = 4π , θ = 90o , t = 0, f = 300MHz, v = 3.108 m/s, λ = m → H ϕ = (cos 2π r + 2π r sin 2π r ) r Hφ Hϕ s = Hφ r 102 101 GuidedWaves & Radiation - sites.google.com/site/ncpdhbkhn 60 r z Basic Antenna Principles (7) I d 2π Hϕ s = sin θ e − j 2π r /λ j + 2 4π λr r I dη − j 2π r / λ cosθ e + Ers = 3 π j 2π r r E = I dη sin θ e− j 2π r /λ j 2π + + λ λ r r j 2π r3 θs π I0 d − j 2π r /λ H = j sin θ e ϕs 2λ r → Eθ s = η Hϕ s → Ers = I 0dη Eθ s = j sin θ e − j 2π r /λ 2λ r d I y x z aφ θ φ y r x GuidedWaves & Radiation - sites.google.com/site/ncpdhbkhn ar aθ 61 Basic Antenna Principles (8) I 0d − j 2π r /λ H = j sin θ e ϕs 2λ r E = j I0 dη sin θ e − j 2π r /λ θ s 2λ r θ Eθ s GuidedWaves & Radiation - sites.google.com/site/ncpdhbkhn 62 Basic Antenna Principles (9) I 0d Hϕ s = j sin θ e − j 2π r /λ λr I0 dη Eθ s = j sin θ e − j 2π r /λ 2λ r Eθ s = η Hϕs Eθ = η Hϕ → I 0d 2π r H = − sin θ sin ω t − ϕ λ r λ 2π r I 0d 2 Sr = Eθ Hϕ = η sin θ sin ωt − λ r λ ϕ =2π θ =π I d 2π r0 2π 2 η ω sin t − S=∫ S r sin θ dθ dϕ = ϕ =0 ∫θ =0 r λ r λ I d π I d → Savr = η = 40π 2λ r 2λ r GuidedWaves & Radiation - sites.google.com/site/ncpdhbkhn 63 z Basic Antenna Principles (10) Savr = Pavr I 0d 40π 2λ r d I y x = I Rradiation Rradiation Pavr 2d = = 80π I0 λ GuidedWaves & Radiation - sites.google.com/site/ncpdhbkhn 64 Basic Antenna Principles (11) d GuidedWaves & Radiation - sites.google.com/site/ncpdhbkhn 65 Basic Antenna Principles (12) I Conductor Monopole I Image I GuidedWaves & Radiation - sites.google.com/site/ncpdhbkhn 66 Contents I Introduction II Vector Analysis III Coulomb’s Law & Electric Field Intensity IV Electric Flux Density, Gauss’ Law & Divergence V Energy & Potential VI Current & Conductors VII Dielectrics & Capacitance VIII Poisson’s & Laplace’s Equations IX The Steady Magnetic Field X Magnetic Forces & Inductance XI Time – Varying Fields & Maxwell’s Equations XII The Uniform Plane Wave XIII Plane Wave Reflection & Dispersion XIV.Guided Waves & Radiation GuidedWaves & Radiation - sites.google.com/site/ncpdhbkhn 67 ... Uniform Plane Wave Plane Wave Reflection & Dispersion Guided Waves & Radiation Guided Waves & Radiation - sites.google.com/site/ncpdhbkhn Guided Waves & Radiation Transmission Line Fields Basic Waveguide... Fiber Basic Antenna Principles Guided Waves & Radiation - sites.google.com/site/ncpdhbkhn 10 Basic Waveguide Operation (1) z d x ε y Parallel-plate waveguide Guided Waves & Radiation - sites.google.com/site/ncpdhbkhn... = ω µε ε y kl θ kl kx θ Guided Waves & Radiation - sites.google.com/site/ncpdhbkhn 13 Basic Waveguide Operation (4) x E H H kl kx E kl z TM TE kl θ kx kl kx θ Guided Waves & Radiation - sites.google.com/site/ncpdhbkhn