TRANSMISSION LINE
FORMULAS Phase constant: B =
6.28/LAMBDA
Input impedance of line length L: Zl = Zo * (Zb + jZo * tan(B * L))/
(Zo + jZb * tan(B * L))
where:
Zb = load impedance
Zo = characteristic impedance of line
Impedance of short circuited line length L: Zsc = jZo * tan(B * L)
Impedance of open circuited line length L: Zoc = -jZo * cotg(B * L)
Impedance of line an odd number of quarter wavelengths long: Z = (Zo
* Zo) / Zb
Impedance of line an integral number of half wavelengths long: Z =
Zb
Voltage Standing Wave Ratio: SWR = Zr / Zo or Zo / Zr; Zr = R
(Imaginary part is 0)
Voltage Standing Wave Ratio: SWR = (1 + SQRT(Pref / Pfor))/(1 -
SQRT(Pref / Pfor))
where:
Pfor = forward power
Pref = reflected power
Voltage Reflection Coefficient: /r/ = (SWR - 1)/(SWR + 1) =
SQRT(Pref / Pfor)
Return Loss: RL (dB) = -20 * log(/r/
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