class, z0=None, Dint=0.00081, Dout=0.005, epsilon_r=1, tan_delta=0, sigma=1e+99, *args, **kwargs)[source]

A coaxial transmission line defined in terms of its inner/outer diameters and permittivity

  • frequency (Frequency object) –
  • z0 (number, array-like, or None) – the port impedance for media. Only needed if its different from the characterisitc impedance of the transmission line. if z0 is None then will default to Z0
  • Dint (number, or array-like) – inner conductor diameter, in m
  • Dout (number, or array-like) – outer conductor diameter, in m
  • epsilon_r=1 (number, or array-like) – relative permittivity of the dielectric medium
  • tan_delta=0 (number, or array-like) – loss tangent of the dielectric medium
  • sigma=infinity (number, or array-like) – conductors electrical conductivity, in S/m

TODO : different conductivity in case of different conductor kind


Dint, Dout, epsilon_r, tan_delta, sigma can all be vectors as long as they are the same length


[1]Pozar, D.M.; , “Microwave Engineering”, Wiley India Pvt. Limited, 1 sept. 2009


Y Distributed Admittance, \(Y^{'}\)
Z Distributed Impedance, \(Z^{'}\)
Z0 Characteristic Impedance, \(Z0\)
alpha real (attenuation) component of gamma
beta imaginary (propagating) component of gamma
gamma Propagation Constant, \(\gamma\)
v_g Complex group velocity (in m/s)
v_p Complex phase velocity (in m/s)


__init__ Initialize self.
attenuator Ideal matched attenuator of a given length
capacitor Capacitor
delay_load Delayed load
delay_open Delayed open transmission line
delay_short Delayed Short
electrical_length calculates the electrical length for a given distance
extract_distance Determines physical distance from a transmission or reflection ntwk
from_Z0_Dout Init from characteristic impedance and outer diameter
from_media Initializes a DistributedCircuit from an existing :class:’~skrf.
impedance_mismatch Two-port network for an impedance mismatch
inductor Inductor
isolator two-port isolator
line Transmission line of a given length and impedance
load Load of given reflection coefficient.
lossless_mismatch Lossless, symmetric mismatch defined by its return loss
match Perfect matched load (\(\Gamma_0 = 0\)).
mode create another mode in this medium
open Open (\(\Gamma_0 = 1\))
random Complex random network.
resistor Resistor
short Short (\(\Gamma_0 = -1\))
shunt Shunts a Network.
shunt_capacitor Shunted capacitor
shunt_delay_load Shunted delayed load
shunt_delay_open Shunted delayed open
shunt_delay_short Shunted delayed short
shunt_inductor Shunted inductor
splitter Ideal, lossless n-way splitter.
tee Ideal, lossless tee.
theta_2_d Converts electrical length to physical distance.
thru Matched transmission line of length 0.
to_meters Translate various units of distance into meters
white_gaussian_polar Complex zero-mean gaussian white-noise network.
write_csv write this media’s frequency,gamma,Z0, and z0 to a csv file.