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4-1 Chapter 4 Reflection and Transmission of Waves ECE 3317 Dr. Stuart Long www.ranamok.com www.bridgat.com

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  • 4-1

    Chapter 4 Reflection and Transmission

    of WavesECE 3317

    Dr. Stuart Long

    www.ranamok.com

    www.bridgat.com

  • 4-2

    w

    n H1

    H2

    H3H4

    ^

    1

    2

    yxl

    (fig. 4.1)

    Boundary Conditions

    -The convention is that is the outward pointing normal at the boundary pointing into region 1

  • 4-3

    w

    n H1

    H2

    H3

    H4

    ^

    1

    2

    yxl

    (fig. 4.1)

    Boundary Conditions

  • 4-4Boundary Conditionsfor H Field

    w

    n H1

    H2

    H3

    H4

    ^

    1

    2

    y

    xl(fig. 4.1)

    www.e-education.psu.edu

  • 4-5

    1 2 s-ˆ ( ) × =H H Jn

    The discontinuity in tangentialmagnetic field is equal to the

    surface current.

    w

    n H1

    H2

    H3

    H4

    ^

    1

    2

    yxl

    (fig. 4.1)

    Boundary Conditionsfor H Field

  • 4-6

    1 2ˆ ( ) 0× =E - E n

    A similar derivation for yieldsjω× = −E B∇

    The tangential electric field is continuous across the boundary

    (no magnetic current source)

    Boundary ConditionsFor E Field

  • 4-7

    s

    tan tan

    The surface current density only exists on a "perfect" conductor.So if both media have finite conductivities t E H hen and are

    both continuous.

    Since the

    We can now deduce that :

    •→

    J

    field cannot exist inside a "perfect" conductorthen the tangential field is zero on the surface

    (i.e field is normal to perfect conductor surface.)

    E -E -

    E -

    Boundary Conditions

  • 4-8

    w

    2

    1

    A

    1n 2n-D D sρ= The discontinuity of the normal D-field is equal to ρs

    Boundary ConditionsFor D Field

  • 4-9

    1n 2nB - B 0=

    The normal B-field is continuous across the boundary

    w

    2

    1

    A

    Boundary Conditionsfor B Field

  • 4-10

    tan tan norm norm

    1t 2t1t 2t

    1 2

    1t 2t1t 2t

    1 2

    1n 2n 1 1n 2 2n

    1n 2n 1 1n 2 2n

    E , H , B , D

    D DE E

    B BH H

    D D

    Are all conti

    E E

    B B

    nuo

    u

    H H

    s

    ε ε

    µ µ

    ε ε

    µ µ

    = =

    = =

    = =

    = =

    Non-Perfect Conductors

    1

    2

    D1

    B2

    B1 E1

    D2 E2

    H1

    H2 ε2μ2

    ε1 μ1

    Boundary ConditionsSummary

  • 4-11

    1 1

    1 1

    1 1

    1 1

    tan tan

    norm norm

    n s n

    t s t

    2 2 2

    s

    2

    1

    1

    = H = B = D = 0

    E 0 D 0

    B 0 H 0

    ˆ D E

    ˆ |H | | J | |B |

    E

    ;

    ; ; | J |

    ss

    s

    ρρ ρ

    ε

    µ

    = =

    = =

    • = = =

    × = = =

    ⇒D

    H J

    n

    n

    Perfect Conductors

    σ = ∞E, H, B, D=0

    n H E^

    Boundary ConditionsSummary

    1

    2

  • 4-12

    - Etan is continuous

    - Htan is discontinuous by |Js|

    - Bnorm is continuous

    - Dnorm is discontinuous by |ρs|

    - Js and ρs exist only on perfect conductors

    - All fields ≡ 0 inside a perfect conductor

    - D = ε E

    - B = μ H

    H

    Js

    BI

    E

    Boundary ConditionsConcepts

  • 4-13

    Consider a uniform plane wavepropagating in and direction, and with the electric field in

    ˆˆ+ +

    ˆ the

    direction.

    z x

    y

    x k

    z

    Surfaces of constant phase

    E H

    (fig. 4.5)

    [4.7]

    Uniform Plane Wave Propagating in an Arbitrary Direction

    k

    kx

    kz

  • 4-14

    Once again we see that H is perpendicular to both E and k

    x k

    z

    Surfaces of constant phase

    E H

    (fig. 4.5)

  • 4-15

    (fig. 4.6)

    Plane Wave Impinging on a Dielectric Interface

    1μ1ε1

    2μ2ε2

    krz

    krx

    ktz

    ktx

    kzkx

    θ

    θr θt

    x

    z

    ki

    kr kt

    ε1= εr1 ε0 ε2= εr2 ε0

    [4.13]

    [4.11]

    [4.15]

    Where Reflection Coefficient Transmission Coeffic

    ientT

    R →→

  • 4-16

    Incident Wave Vector

    Reflected Wave Vector

    Transmitted Wave Ve t

    c or

    ˆ ˆ

    ˆ

    ˆ ˆ

    ˆ x z

    t x t

    r

    z

    x r zk k

    k

    k

    k

    k= +

    = −

    = +t

    r

    ik

    k x

    k

    x

    z

    z

    x z1

    μ1ε12

    μ2ε2

    krz

    krx

    ktz

    ktx

    kzkx

    θ

    θr θt

    x

    z

    ki

    kr kt

    (fig. 4.6)

    Plane Wave Impinging on a Dielectric Interface

  • 4-17

    Remember that Etan is continuous at

    the boundary (z=0) thus we have :

    -- + rxx txj j xkj x xk kTeee R =

    To be true for all values of x

    kx = krx = ktxPhase matching condition

    The tangential components of the three wave vectors are equal

    0 00ˆ ˆ=ˆ rx r tx tz z zxjk x jk x j jk x jk kkz zzjE R T Ee eE e− +− − −− + yy y

    [4.19]

    [4.17]

    Plane Wave Impinging on a Dielectric Interface

  • 4-18

    2 21 1

    2

    2 21 1

    2 22

    0

    0

    0

    ω µ

    ω µ ε

    ω µ ε

    ε

    ∇ + =

    ∇ + =

    ∇ + =

    t

    i

    rE

    E

    E

    Each wave satisfies the appropriate Maxwell equations therefore the wave

    equations become:

    In medium 1

    In medium 2

    1μ1ε1

    2μ2ε2

    krz

    krx

    ktz

    ktx

    kzkx

    θ

    θr θt

    x

    z

    kI

    kr kt

    (fig. 4.6)

    Plane Wave Impinging on a Dielectric Interface

  • 4-19

    2 21 1 1

    2

    2 2

    21 1 1

    2 2

    2 2

    2 22 2 2

    r x rz

    x

    t

    z

    t x z

    k

    k

    k

    kk

    k

    k

    k

    k

    ω µ ε

    ω µ ε

    ω µ ε

    + =

    =+

    =

    =

    =

    + =

    θr

    krx

    krz

    k1

    [4.20a]

    [4.20b]

    [4.21]

    θt

    ktx

    ktz

    k2

    θkx

    kz

    k1

  • 4-20

    From geometry and an understanding of the phase matching condition we obtain :

    1

    2

    1 sin

    sin

    sin

    r

    x t

    x

    x

    t

    r

    k

    k

    k

    k k

    k

    θ

    θ

    θ=

    =

    = 11 2sins inin sr tk kk θθθ = =

    θr= θ

    angle of incidence is equal to angle of reflection

    krz = kz

    Snell’s Law (law of refraction)

    k1sin θ = k2sinθt

    1μ1ε1

    2μ2ε2

    krz

    krx

    ktz

    ktx

    kzkx

    θ

    θr θt

    x

    z

    kI

    kr kt

    (fig. 4.6)

    [4.25]

  • 4-21Graphical Representation of Phase Matching Conditions

    Radius=k1

    k1

  • 4-22

    (fig 4.7b)

    Radius = k1

    k1>k2

    θ

    θr θt

    kx

    ki

    kr

    ktRadius = k2

    kz

    Note: wave bent away from normal

    Graphical Representation of Phase Matching Conditions

    For the case where k1 > k2

  • 4-23

    Radius = k1

    k1>k2

    θθr θt

    kx

    ki

    kr kt Radius = k2kz

    Note: wave bent away from normal

    Graphical Representation of Phase Matching Conditions

    Another case where k1 > k2(θ increased)

  • 4-24

    Radius = k1

    k1>k2

    θc

    θr θt

    kx

    ki

    kr ktRadius = k2

    θ=θc

    kz

    2 1 sink k θ=θt=90°

    Graphical Representation of Phase Matching Conditions

    For the case where k1 > k2at the critical angle

  • 4-25

    In medium 2 wave propagates in + direction, but is attenuated in the +z direction . Non-uniform plane wave

    also called a surface or effinesant wave

    2 2 2 2 2 22 2 -x tz tz xk k k k k k⇒+ = =

    [4.26]

    θt

    kx

    ktz

    k2

  • 4-26

    [4.27]

    x 2 2 1

    2

    1

    If ;

    whe

    sin

    sire n

    c c

    c

    θ θ k k k k θ

    k

    = = ⇒ =

    =

    Critical Angle Angle of incidence above which total

    internal reflection occurs. It can only occur when k1>k2.

    x

    z

    c θ

    c θ

    Critical Angle θc

  • 4-27Magnitude of Reflected and Transmitted Waves

    - Depends on polarization of E

    - The plane of incidence is defined by the plane formed by the unit normal v vector normal to the boundary and the incident wave vector.

    Case I Perpendicularly PolarizedCase II Parallel Polarized

    ik

  • 4-28

    z

    x

    ki

    HiEi

    ktkr

    HrErHt

    Et

    Case I: E-field Perpendicular to Plane of Incidence

    θ

    Magnitude of Reflected and Transmitted Waves

  • 4-29

    The incident wave is given by

    [4.11]

    [4.12]

    Case I: E-field Perpendicular to Plane of Incidence

    z

    x

    ki

    HiEi

    ktkr

    HrEr HtEt

    θ

    Magnitude of Reflected and Transmitted Waves

    of region 1

  • 4-30

    The reflected wave is given by

    [4.13]

    [4.14]

    Case I: E-field Perpendicular to Plane of Incidence

    z

    x

    ki

    HiEi

    ktkr

    HrEr HtEt

    θ

    Magnitude of Reflected and Transmitted Waves

    of region 1

  • 4-31

    The transmitted wave is given by

    [4.15]

    [4.16]

    Case I: E-field Perpendicular to Plane of Incidence

    z

    x

    ki

    HiEi

    ktkr

    HrEr HtEt

    θ

    Magnitude of Reflected and Transmitted Waves

    of region 2

  • 4-32

    ✔ Quick Review

    θ

    ktz

    k1kx

    z

    x

    θt

    kx

    ktz

    k2

  • 4-33

    1tan 2 tan

    1tan 2

    ( ) ( )0

    ( )

    1

    ta

    1

    0

    2

    n

    0

    1

    xx xj k

    i r ty y y y

    i r

    j k xI

    I

    z

    tx

    j k xI

    I

    tz II

    x

    z

    x

    x

    x

    T E e

    T

    k T

    R E e

    E E E E E E

    H H H

    E

    k

    e

    k R

    H H

    R

    H

    ω µµ ω ωµ

    − − −

    = ⇒ ⇒ + =

    + =

    + =

    = ⇒ ⇒ + =

    −− + =NOTE: At z=0

    both Etan and Htanmust be

    continuous

    Case I: E-field Perpendicular to Plane of Incidence

    At z=0

    At z=0

    z

    x

    ki

    HiEi

    ktkr

    HrEr HtEt

    θ

    Magnitude of Reflected and Transmitted Waves

  • 4-34

    2

    2

    2

    1

    2 1

    2 1

    1

    1

    2

    Using the previou

    1 s 2 equations

    we can find

    I

    t

    I

    z I z I

    z

    z

    Iz t

    z tzI

    z tz

    z

    R

    k R

    T

    k T

    kT

    k

    k k

    k kRk k

    ωµ

    µµ

    ωµ

    µ µµ µ

    µ

    ωµ−

    =

    + =

    +

    +

    − =

    −=

    +Reflection coefficient for

    perpendicularly polarized wave

    Transmission coefficient for perpendicularly polarized wave

    [4.22]

    [4.23]

    Case I: E-field Perpendicular to Plane of Incidencez

    x

    ki

    HiEi

    ktkr

    HrEr HtEt

    θ

    Magnitude of Reflected and Transmitted Waves

  • 4-35

    1 2 0

    For nonmagnetic

    materials

    equ. 4.23

    and 4.23 reduce to:

    2

    zI

    z t

    z

    z

    z

    tzI

    z t

    kk k

    k k

    kR

    kT

    µ µ µ

    =

    −+

    +

    =

    = =

    Reflection coefficient for perpendicularly polarized wave

    Transmission coefficient for perpendicularly polarized wave

    Case I: E-field Perpendicular to Plane of Incidencez

    x

    ki

    HiEi

    ktkr

    HrEr HtEt

    θ

    Magnitude of Reflected and Transmitted Waves

  • 4-36

    Case II: E-field Parallel to Plane of Incidence

    (fig. 4.9)

    z

    x

    ki

    Hi

    Ei

    ktkr

    Hr

    Er Ht

    Et

    θθt

    Magnitude of Reflected and Transmitted Waves

  • 4-37

    The incident wave is given by

    [4.28]

    [4.29]

    Case II: E-field Parallel to Plane of Incidence

    (fig. 4.9)

    z

    x

    ki

    Hi

    Ei

    ktkrHr

    Er Ht

    Et

    θθt

    Magnitude of Reflected and Transmitted Waves

  • 4-38

    The reflected wave is given by

    [4.30]

    [4.31]

    Case II: E-field Parallel to Plane of Incidence

    (fig. 4.9)

    z

    x

    ki

    Hi

    Ei

    ktkrHr

    Er Ht

    Et

    θθt

    Magnitude of Reflected and Transmitted Waves

  • 4-39

    The transmitted wave is given by

    [4.32]

    [4.33]

    Case II: E-field Parallel to Plane of Incidence

    (fig. 4.9)

    z

    x

    ki

    Hi

    Ei

    ktkrHr

    Er Ht

    Et

    θθt

    Magnitude of Reflected and Transmitted Waves

  • 4-40

    2

    2

    1

    1

    2 1

    2

    Using Boundary Conditions as previously done for Case I we obtain:

    2

    z tzIIz tz

    zII

    z tz

    k kR

    k k

    kT

    k kε

    ε

    εε ε

    ε

    ε −

    =+

    =+

    Reflection coefficient for parallel polarized wave

    Transmission coefficient for parallel polarized wave

    [4.34]

    [4.35]

    Case II: E-field Parallel to Plane of Incidence

    (fig. 4.9)

    z

    x

    ki

    Hi

    Ei

    ktkrHr

    Er Ht

    Et

    θθt

    Magnitude of Reflected and Transmitted Waves

  • 4-41Conditions for No Reflection

    1 2 0

    Total Transmission

    For non-magnetic dielectrics

    Case I: For perpendicular polarized

    0

    0

    I z tz

    R

    R k k

    µ µ µ

    =⇒

    =

    = =

    1 2 1 2

    Since we already know , this is only possible

    if , thus we find that for total transmission

    to occur both media must be the sa nome ( interfac

    e at all)

    x txk k

    k k ε ε

    =

    =⇒=

    z tzIz tz

    k kRk k

    −=

    +

  • 4-42

    2 1Case II: For parallel polarized

    along with the phase matching condition we

    find that for total transmission to occur the

    the angl

    0

    e of

    II z tzR k kε ε= =⇒

    1 2

    1

    inci

    dence must be

    tanbθεε

    −=Brewster Angle or

    Polarization AngleAngle of incidence at which the wave is

    totally transmitted. It can exist only when incident wave is parallel polarized for non-

    magnetic dielectrics .

    b θ[4.36]

    Conditions for No Reflection

    2 1

    2 1

    z tzII

    z tz

    k kRk k

    ε εε ε

    −=

    +

  • 4-43

    b θ

    0=2.25The material is glass with The Brewster angle is 56

    ε ε≈ °

    (fig 4.10)

  • 4-44Reflection from a Perfect Conductor

    Oblique Incidence

    Perfect Conductor

    z

    x

    ki

    HiEi

    krHr

    Er

    θ

    (fig 4.16)

  • 4-45

    Perfect conductor

    z

    x

    ki

    HiEi

    krHr

    Er

    θ

    (fig 4.16)

    Reflection from a Perfect Conductor

    [4.22]

    [4.23]

  • 4-46

    Perfect conductor

    z

    x

    ki

    HiEi

    krHr

    Er

    θ

    (fig 4.16)

    Reflection from a Perfect Conductor

    [4.34]

    [4.35]

  • 4-47Normal Incidence of a Plane Wave on a Perfect Conductor

    ki

    Hi

    Ei

    kr

    Hr

    Er PerfectConductor

    z

    x

    (fig 4.14a)

  • 4-48

    0

    0

    0

    0

    0

    0

    ˆ

    ˆ

    ˆ

    ˆ

    0

    jkz

    j

    jk

    z

    z

    k

    jkz

    E e

    E eE

    E e

    η+

    +

    = −

    =

    =

    =

    = =

    r

    r

    t

    i

    t

    i

    E

    E

    H

    E H

    H

    x

    y

    x

    y

    [4.44a]

    Perfectconductor

    z

    x

    kr

    Hr

    Er

    kiHi

    Ei

    [4.44b]

    [4.45a]

    [4.45b]

    Normal Incidence of a Plane Wave on a Perfect Conductor

    Etotal= Ei + Er

    Htotal= Hi + Hr

  • 4-49

    [4.46a]

    [4.46b]

    Normal Incidence of a Plane Wave on a Perfect Conductor Perfect

    conductorz

    x

    kr

    Hr

    Er

    kiHi

    Ei

  • 4-50

    [4.47]

    [4.49]

    [4.48]

    Normal Incidence of a Plane Wave on a Perfect Conductor Perfect

    conductorz

    x

    kr

    Hr

    Er

    kiHi

    Ei

  • 4-51

    2 kz π= − kz π= − 0

    0 2E

    Efig(4.14b)

    Normal Incidence of a Plane Wave on a Perfect Conductor

    Standing-wave pattern of the E field

  • 4-52

    3 2

    kz π= − 2

    kz π= −

    0

    0

    2E

    η

    Standing-wave pattern of the H field

    fig(4.14c)

    H

    Normal Incidence of a Plane Wave on a Perfect Conductor

    0

  • 4-53

    Perfect Conductor

    z

    x

    ki

    HiEi

    krHr

    Er

    θ

    Note:

    where:

    sin cos

    ˆ ˆˆ ˆ

    x zx

    x

    z

    z

    k kk

    k kk

    k

    k

    θθ

    = +

    =

    =

    =

    r

    i

    k zk

    xx - z(fig 4.16)

    Oblique Incidence of a Perpendicularly Polarized Plane Wave on a Perfect Conductor

  • 4-54

    ( )

    0

    0

    0

    0

    ˆ

    ˆ

    ˆ

    ˆ

    0

    jk x jk z

    jk x j

    jk x jk z

    jk x jk z

    k z

    x z

    x

    x z

    z

    z

    x

    E e

    E

    E e

    E e

    ek

    k

    η

    η

    − +

    − −

    +

    − −=

    ×=

    = −

    ×=

    =

    =

    i

    r

    y

    k -

    y

    y

    k y

    r

    r

    t

    i

    t

    i

    E

    H

    H

    E

    E

    H

    [4.51a]

    [4.51b]

    Perfect conductor

    z

    x

    ki

    HiEi

    krHr

    Er

    θ

    (fig 4.16)

    Note: 1IR = −

    Oblique Incidence of a Perpendicularly Polarized Plane Wave on a Perfect Conductor

    Has magnitude 1 in the direction of H

  • 4-55

    ( ) ( )

    ( ){( ) }

    sin0

    0

    sin

    Total fields in medium 1

    ˆ -2 sin cos

    ˆ 2cos cos cos

    ˆ 2 sin sin cos

    jkx

    jkx

    jE kz e

    E kz

    j kz e

    θ

    θ

    θ

    θ θη

    θ θ

    =

    =

    +

    y

    x -

    z -

    E

    H

    Perfect conductor

    z

    x

    ki

    HiEi

    krHr

    Er

    θ

    (fig 4.16)

    Oblique Incidence of a Perpendicularly Polarized Plane Wave on a Perfect

    Conductor

  • 4-56

    0

    0 2E

    Standing-wave pattern of the Ey field

    fig(4.17)

    y E

    Oblique Incidence of a Perpendicularly Polarized Plane Wave on a Perfect Conductor

    kz-π/cosθ-2π/cosθ

    -λ/cosθ -λ/2cosθ 0 z

  • 4-57

    0

    02E cos θη

    Standing-wave pattern of the Hx fieldx H

    Oblique Incidence of a Perpendicularly Polarized Plane Wave on a Perfect Conductor

    kz-π/2cosθ-3π/2cosθ

    -3λ/4cosθ -λ/4cosθ 0 z

  • 4-58

    Standing-wave pattern of the Hz field

    02E sin θη

    z H

    Oblique Incidence of a Perpendicularly Polarized Plane Wave on a Perfect Conductor

    kz-π/cosθ-2π/cosθ

    -λ/cosθ -λ/2cosθ 0 z

  • 4-59Oblique Incidence of a Perpendicularly Polarized

    Plane Wave on a Perfect Conductor

    Summary

  • 4-60Power Conservation

  • 4-61Power Conservation

    Pr

    Pt

  • 4-62Example 1

    [ ]

    0

    100 MHz

    V1m

    f

    E

    =

    = = i

    E

    1 1 1 0 00

    8

    1 8

    2 2 0

    1

    21

    0

    2

    2 10 233 10

    2 443 3r

    fk

    m

    k m

    v

    k

    πω µ ε ω µ ε

    π π

    π πω µ ε ω µ ε ε

    = = =

    ×= =

    ×

    = = = ⋅ =

    1 0µ µ= 2 0µ µ=

    1 0ε ε= 2 04ε ε=

    z

    x

    ki

    HiEi

    ktkr

    HrEr HtEt

    30i rθ θ= = °

  • 4-63

    [ ]

    0

    100 MHz

    V1m

    f

    E

    =

    = = i

    E

    1 2

    1

    2

    1

    sin sin

    1 sin sin sin30 0.262

    sin 0.26 14.48

    i t

    t i

    t

    k k

    kk

    θ θ

    θ θ

    θ − ⇒

    =

    = = =

    = °

    Example 1 Cont.

    1 0µ µ= 2 0µ µ=

    1 0ε ε= 2 04ε ε=

    z

    x

    ki

    HiEi

    ktkr

    HrEr HtEt

    30i rθ θ= = °

  • 4-64

    1 1

    1 1

    2 2 2 2 22 1 1 1

    2 1 1 1

    you can check by noting that

    sin 0.5

    cos 0.866

    - 4 sin 1.94

    cos 4 cos 2 cos14.5 1.94

    x i rx tx

    z i rz

    tz x i

    tz t t

    k k k k k

    k k k k

    k k k k k k

    k k k k k

    θ

    θ

    θ

    θ θ

    = = = =

    = = =

    = = − =

    = = = =

    1 0µ µ= 2 0µ µ=

    1 0ε ε= 2 04ε ε=

    z

    x

    ki

    HiEi

    ktkr

    HrEr HtEt

    30i rθ θ= = °

    Example 1 Cont.

  • 4-65

    ( )

    2 1

    1 1

    1

    2 1

    12

    2 1 1 1

    1

    Note:

    0.866 1.94 0.3820.866 1.

    2 0.8662

    2 0.6180.866

    94

    1+

    1.94

    0

    z zI

    z tz z t

    I

    z tz z tzI

    z tz z

    z

    I

    tz

    I

    k kR

    kk kTk k k k k k

    k k k kRk k k k

    T

    k

    R

    k

    µ µµ

    µ

    µ

    µµ

    = =

    =

    =

    −=

    − −

    = =+

    + +

    +

    = −+

    =

    +

    (-.6 0.118 382)= +

    1 0µ µ= 2 0µ µ=

    1 0ε ε= 2 04ε ε=

    z

    x

    ki

    HiEi

    ktkr

    HrEr HtEt

    30i rθ θ= = °

    Example 1 Cont.

  • 4-66

    22 2 20

    r1

    2 20 0

    0 0

    2 2 20 0 0

    0 0 0

    2

    20

    i

    22

    1

    20 0

    0

    0

    0

    2t

    2

    S = =

    2 2

    2 2 2

    2

    S 1 = 1

    S

    0.14

    1

    2

    22

    59

    2

    2

    I I I

    I I

    E E

    E E E

    E T

    E

    E

    E

    R R

    E

    R

    T

    η η

    η η η

    ηη η

    η

    η

    =

    =

    =

    =

    20

    0

    22 = 0.7 6 9 32I

    T Eη

    1 0µ µ= 2 0µ µ=

    1 0ε ε= 2 04ε ε=

    z

    x

    ki

    HiEi

    ktkr

    HrEr HtEt

    30i rθ θ= = °

    0.382

    0.618

    I

    IT

    R

    =

    = −

    Example 1 Cont.

  • 4-67

    2 20 0

    0 0

    2 20 0

    0 0

    2 20 0

    0

    i

    0t t

    i

    r rS S cos = cos

    S S cos = 1 cos3

    30

    S S cos 0.7639 cos1

    0 = 0.8660

    4.48 0.7396

    =0 0.1264

    2 2

    2 2.1459

    2

    2

    rz

    iz

    tz

    E E

    E E

    E E

    η η

    η η

    η η

    θ

    θ

    θ

    =

    =

    = =

    =

    2 2 20 0 0

    0 0i

    0tr S 0.76390.1459 S 1 ; ;2 2

    S 2

    E E Eη η η

    ===

    Example 1 Cont.

  • 4-68

    20

    0

    20

    0

    20

    0

    2

    0.7396

    0.1264

    t

    0.8660

    2

    ref

    in 2

    r

    c.

    n.

    .

    a

    E

    E

    E

    η

    η

    η

    +

    ( )see p.99 for general proof

    2 2 20 0 0

    0 0i

    0trS =S = ; ; 2 2

    S 0.8660 0.7396 0.1264 2zzz

    E E Eη η η

    =

    Example 1 Cont.

  • 4-69

    z

    x

    ki

    HiEi

    ktkr

    HrEr HtEt

    Example 1 Cont.

  • 4-70

    Im

    Re

    Example 1 Cont.

  • 4-71

    0

    1.38

    z

    Standing-wave pattern of the |Ey | field

    0.62

    -0.87 -1.73 -3.46

    2y E

    1y E

    ytotalE

    Example 1 Cont.

  • 4-72

    cos 0.866sin 0.5

    i

    i

    θθ

    =

    =z

    x

    ki

    HiEi

    ktkr

    HrEr HtEt

    Example 1 Cont.

  • 4-73

    0

    1

    1.2 η

    z

    Standing-wave pattern of the |Hx | field

    -0.87 -1.73 -3.46

    2x H 1x H

    totalHx

    1

    0.54 η

    Example 1 Cont.

  • 4-74

    0

    1

    0.69 η

    z -0.87 -1.73 -3.46

    2z H 1z H

    1

    0.31 η

    Standing-wave pattern of the |Hz | field

    totalH z

    Example 1 Cont.

  • 4-75

    2cos 1.94t rθ ε =z

    x

    ki

    HiEi

    ktkr

    HrEr HtEt

    Example 1 Cont.

  • 4-76

    Example 2

    [ ]50 Hzf =

    1 0µ µ=

    2 0µ µ=

    1 0ε ε=

    z

    ki

    Hi

    Ei

    2 081ε ε=sea

    water

    mho4

    mσ =

    airAt an Air Seawater boundary, calculate the power density in seawater as compared to that in air for a normally incident wave.

  • 4-77Example 2 Cont.

    [ ]50 Hzf =

    1 0µ µ=

    2 0µ µ=

    1 0ε ε=

    z

    ki

    Hi

    Ei

    2 081ε ε=sea

    water

    mho4

    mσ =

    air

  • 4-78Example 2 Cont.

    [ ]50 Hzf =

    1 0µ µ=

    2 0µ µ=

    1 0ε ε=

    z

    ki

    HiEi

    2 081ε ε=sea

    watermho

    4m

    σ =

    air

  • 4-79

    z

    x

    ki

    HiEi

    kr

    Hr

    Er

    θ

    ( )

    0

    0

    sin0

    0

    sin0

    0

    ˆ

    ˆ

    ˆˆ 2cos cos cos

    2ˆ cos

    z

    z

    jkx

    z o

    jkx

    E kz e

    E e

    θ

    θ

    θ θη

    θη

    =

    =

    =

    ×

    ×

    = × −

    =

    n

    z

    z x

    y

    S

    S

    S

    S

    J = H

    J = (- ) H

    J (- )

    J

    k

    H E

    x

    z

    y

    produces currents only indirection

    wire grid

    Direction of Surface Currents

  • 4-80Wave Incident on a “Good Conductor”

    z

    ki

    ktkr

    x

    θtθi

    z

    E

  • 4-81Example 3 [ ]300 MHz

    parallel polarizedf =

    ( )Prob. 4.101 0µ µ= 2µ

    1 0ε ε= 2 0ε ε=

    4530

    i r

    t

    θ θθ

    = = °

    = °

    z

    x

    ki

    Hi

    Ei

    ktkrHr

    Er Ht

    Et

    θθt

  • 4-82

    [ ] 1

    0

    1

    0

    1

    1

    ( sin c

    ( sin cos )

    os )01 1

    1

    2 ( )2

    01 1

    1

    2 ( )

    0

    0

    0

    20

    ˆ ˆ( cos ) sin )

    2 ˆ ˆ

    ˆ ˆ( cos sin )

    2 ˆ ˆ( )

    ( )2

    2

    i

    i

    i

    ij k x k zi i

    jk x z

    j k x k zIIi i

    jk x zII

    R Hk k e

    H e

    e

    R

    H

    e

    k

    H

    k

    θ

    θ

    θ

    θ

    θ θωε

    η

    θ θωε

    η

    − −

    − −

    − +

    − +

    = −

    =

    =

    = − −

    − −

    i

    i

    r

    r

    E

    E

    E

    E

    x z

    x z

    x z

    x z

    ( )Prob. 4.10 1 0µ µ= 2µ1 0ε ε= 2 0ε ε=

    4530

    i r

    t

    θ θθ

    = = °

    = °

    z

    x

    ki

    Hi

    Ei

    ktkrHr

    Er Ht

    Et

    θθt

    Example 3 Cont.

  • 4-83

    ( )

    2 21 2

    0

    ( sin )2 2 02 1

    2

    (0.707 1.335 )0 0

    ˆ ˆ( sin )

    0.536 ˆ ˆ32

    i xj k x k k zIIx i

    jk x z

    T Hk k k e

    H e

    θθωε

    η

    − + −

    − +

    = − −

    = −

    t

    t

    E

    E

    x z

    x z

    ( )Prob. 4.10

    1 0µ µ= 2µ

    1 0ε ε= 2 0ε ε=

    4530

    i r

    t

    θ θθ

    = = °

    = °

    z

    x

    ki

    Hi

    Ei

    ktkrHr

    Er Ht

    Et

    θθt

    Example 3 Cont.

  • 4-84

    0

    0.656

    z

    0

    - 22kπ

    0

    - 2 kπ

    0 0

    ExH η

    0.758

    ( )Prob. 4.10Example 3

    Cont.

  • 4-85

    ( )

    ( )

    2 2 2r

    21i 0

    2 222

    2 20 00 0

    2 2

    t

    20 0 00 0 0

    2 2 20 0 00 0 0

    10

    0

    2

    S 1 = 2 2

    2 2 2

    2 2

    S = 2 2 2

    0.005S = = 2

    1 1= Re2 2

    1 1 2

    2

    2 II I

    II III

    I II

    I

    H H

    H H

    T T

    H

    H H

    R R

    T

    H

    H

    H

    H

    H R

    η η

    η η η

    η η

    η

    η

    η

    η

    η

    × =

    =

    =

    = =

    S E H

    0.81 23

    ( )Prob. 4.10

    0.0718 1.0718 ; IIIIR T ==

    1 0µ µ= 2µ

    1 0ε ε= 2 0ε ε=

    4530

    i r

    t

    θ θθ

    = = °

    = °

    z

    x

    ki

    Hi

    Ei

    ktkrHr

    Er Ht

    Et

    θθt

    Example 3 Cont.

  • 4-86

    2 20 00 0

    2 20 00 0

    2 20 00 0t

    i

    r

    i

    r

    t

    0.0052

    S

    S S cos = cos4

    S S cos 0.8123 cos30 0.

    5 = 0.0036

    S cos = 1 cos4 2 2

    2 2

    2 2

    5 = 0.7071

    7035

    r

    iz

    tz

    z

    H H

    H H

    H H

    η ηθ

    ηθ

    η

    η ηθ

    = = =

    =

    =

    ( )Prob. 4.10

    2 2 20 0 00 r 0t0i S 0.80.0052 S 1 ; ; 12S 2 2

    3 2

    H H Hη η η ===

    Example 3 Cont.

  • 4-87

    t2 2 20 0 0

    0i 0 0r; ;2 2S 0.7S 0.S 0.7071 0036

    2 035z zz H H H

    η η η

    ==

    =

    ( )Prob. 4.10

    200

    200

    200

    2

    2

    0.707

    0.703

    0.00

    1

    36

    in c.

    5

    tra

    ref

    .

    .

    2

    n

    H

    H

    H

    η

    η

    η

    +

    Example 3 Cont.

  • 4-88

    ECE 3317- Chapter 4 Reflection and Transmission of Waves

    Slide Number 1Slide Number 2Slide Number 3Slide Number 4Slide Number 5Slide Number 6Slide Number 7Slide Number 8Slide Number 9Slide Number 10Slide Number 11Slide Number 12Slide Number 13Slide Number 14Slide Number 15Slide Number 16Slide Number 17Slide Number 18Slide Number 19Slide Number 20Slide Number 21Slide Number 22Slide Number 23Slide Number 24Slide Number 25Slide Number 26Slide Number 27Slide Number 28Slide Number 29Slide Number 30Slide Number 31Slide Number 32Slide Number 33Slide Number 34Slide Number 35Slide Number 36Slide Number 37Slide Number 38Slide Number 39Slide Number 40Slide Number 41Slide Number 42Slide Number 43Slide Number 44Slide Number 45Slide Number 46Slide Number 47Slide Number 48Slide Number 49Slide Number 50Slide Number 51Slide Number 52Slide Number 53Slide Number 54Slide Number 55Slide Number 56Slide Number 57Slide Number 58Slide Number 59Slide Number 60Slide Number 61Slide Number 62Slide Number 63Slide Number 64Slide Number 65Slide Number 66Slide Number 67Slide Number 68Slide Number 69Slide Number 70Slide Number 71Slide Number 72Slide Number 73Slide Number 74Slide Number 75Slide Number 76Slide Number 77Slide Number 78Slide Number 79Slide Number 80Slide Number 81Slide Number 82Slide Number 83Slide Number 84Slide Number 85Slide Number 86Slide Number 87Slide Number 88