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4-1 第四章 Patch 天線設計 4-1 設計目的 早期的 Patch 天線大都用於高效能飛機、太空梭人造衛星和飛彈。因為這些 飛行器的天線具有傳送接收信號功能之外,且不會影響飛行器的運行,因此必須 限制天線的尺寸、形狀、成本以及是否易於安裝。而 Patch 天線是由一段長度為 〝L〞與寬度為〝W〞的微帶線所組成的天線,理論於 1950 年被提出並於 1955 年發表。但一直到 1970 年後才被實用化,其結構如圖 4-1 所示,其中在基板上 方方形之金屬貼片,稱之為 Patch圖 4-1 Patch 天線幾何圖 一般典型應用的 Patch 幾何形狀可以有不同變化,如圖 4-2 所示︰ 圖 4-2 Patch 幾何形狀

第四章Patch 天線設計

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  • 4-1

    Patch

    4-1

    Patch

    Patch

    LW 1950 1955

    1970 4-1

    Patch

    4-1 Patch

    Patch 4-2

    4-2 Patch

  • 4-2

    Patch

    MMIC(Monolithic microwave integrated circuit)

    Q( 100)

    (poor polarization purity)

    (Q

    WBW 0= )

    4-2

    patch

    (transmission line model)(cavity model)(full-wave

    analysis)

    (1)

    patch

    (2)

    E H H (Perfect magnetic

    wall)(PMC) patch PMC

    (3)

  • 4-3

    FEKOIE3DEnsemble Momentum

    FEKO

    (Full wave analysis)

    patch (Low-profile antenna)

    Patch

    Patch

    Patch Patch

    ()

    patch

    4-3 W L

    (W )

    TM

    4-5

    1979 (Cavity model) Patch

    (close proximity)

    E H H

    z

    H H

  • 4-4

    (PMC)(Perfect electric wall)

    TM

    (Slot antenna)

    Patch [1] Patch

    Patch

    (a)

    (Fringing field)(Fringing effect)

    4-3 4-4

    Patch Patch Wh

    W/h r L/h>>1

    W

    Patch

    4-3

  • 4-5

    4-4

    4-5 (

    )(Inhomogeneous

    media) 4-5

    W/h>>1 r >>1

    4-6

    eff [1]

    4-5 4-6

    (b)

    Patch

    ()

    r h

  • 4-6

    ()

    (1) Patch WL

    [1] W

    1

    221

    22

    1 000 +

    =+

    =rrrr ff

    w

    (4-1)

    0 (free-space)

    (2) W reff

    wh

    rrreff /121

    12

    12

    1+

    +

    +=

    (4-2)

    (3)(4-3) 4-7 L

    +

    ++

    =

    8.0)258.0(

    264.0)3.0(412.0

    hw

    hw

    hL

    reff

    reff

    (4-3)

    (4) L effL

    LLLeff += 2

    (5)

    ( )( )

    0010

    0

    12 2 2r reff reff r

    fL L L

    = =+

    (4-4)

    (4-4)TM

    (4-3) L

    Lf

    Lreffr

    = 22

    1

    00 (4-5)

  • 4-7

    LL

    4-7

    ()

    patch

    4-7 (Radiating slot)

    4-8

    (slot)[1]

    111 jBGY +=

    W

    ( )

    = 20

    01 24

    11120

    hkWG

    101

    0