Transmisson Line Parameters

L is the inductance per unit length.

C is The shunt capacitance (between the conductors) per unit length.

R is the series resistance of the conductors (both) per unit Length.

G is the shunt conductance from dielectric losses per unit length.

mu = mu0 mur is the permeability

e = epsilon' - j epsilon'' is the permitivity

epsilon' is the real part of the permitivity

epsilon'' the complex part of the permitivity

Rs = (omega mu / 2 sigma)0.5 is the skin resistance

dels = (2 / omega mu sigma)0.5 is the skin depth

omega is the frequency in radians per second

Z0 = (L / C)0.5 is the loss less impedance.

(mu0 / epsilon0)0.5 = 377 ohms is the intrinsic impedance of free-space.

Coaxial

  • L = (mu / 2pi) ln(b / a)
  • C = 2pi epsilon' / ln(b / a)
  • R = (Rs / 2pi) (1/a + 1/b)
  • G = 2pi omega epsilon'' / ln(b / a)
  • Z0 = (mu / epsilon')0.5 ln(b / a) / 2pi

Two-Wire

  • L = (mu / pi) arccosh(D / 2a)
  • C = pi epsilon'/ arccosh(D / 2a)
  • R = Rs / pi a
  • G = pi omega epsilon'' / arccosh(D / 2a)
  • Z0 = (mu / epsilon')0.5 arccosh(D / 2a) / pi

Parallel Plate

  • L = mu d / W
  • C = epsilon' W / d
  • R = 2Rs / W
  • G = omega epsilon'' W / d
  • Z0 = (mu / epsilon')0.5 d / W