1. Welcome to our site! Electro Tech is an online community (with over 170,000 members) who enjoy talking about and building electronic circuits, projects and gadgets. To participate you need to register. Registration is free. Click here to register now.
    Dismiss Notice

Transmission Line 'Gamma' Plane

Discussion in 'Radio and Communications' started by rashiidsherif93, Jan 12, 2016.

  1. rashiidsherif93

    rashiidsherif93 New Member

    Jan 12, 2016
    Hello all,

    I am trying to tackle a question at University on my Radio frequency module and it is regarding to transmission lines.
    The questions goes like the following:

    Why the magnitude of Г is equal to or less than 1?
    What is the physical meaning of the phase of Г?
    What is the increment of length of a transmission line corresponding to a rotation of 2π of Г ?

    What is the length of the transmission lines having the reflection coefficients Г0 and Г(d) shown below:


    I understand that with capital gamma ' reflection coefficient' if it is 1 , no power is delivered to the load , if it is 0 full power is delivered to the load. However my theory understanding stops there, could someone clarify these questions for me?

    Thanks in advance
    Last edited: Jan 13, 2016
  2. Tony Stewart

    Tony Stewart Well-Known Member Most Helpful Member

    Aug 31, 2012
    Richmond Hill , ON Canada near Toronto
    you cannot reflect more power than applied so the worst case reflection = 1 or in log scale 0dB

    The best case is nothing reflected thus a value of 0. (nothing reflected)

    But in practice ,in log scale, -15dB limit may be ok, or more negative for more critical applications.

    When waves have a speed on T line which depends on dielectric constant and speed of light, it produces natural wavelengths, where 1 wavelength is 360deg. A transmission line is said to be harmonic at multiples of 1/2 wavelengths , like a skipping rope or guitar string.

    When odd multiples of a quarter wavelength, impedance is converted in both phase and amplitude. e.g an open cct becomes short and visa versa. are special cases.
    Last edited: Jan 17, 2016

Share This Page