# Transmission Line 'Gamma' Plane

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

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1. ### rashiidsherif93New Member

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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?

Last edited: Jan 13, 2016
2. ### Tony StewartWell-Known MemberMost Helpful Member

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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