class, z0=None, C=9e-11, L=2.8e-07, R=0, G=0, *args, **kwargs)[source]

A transmission line mode defined in terms of distributed impedance and admittance values.

  • frequency (Frequency object) – frequency band of the media
  • 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
  • C (number, or array-like) – distributed capacitance, in F/m
  • L (number, or array-like) – distributed inductance, in H/m
  • R (number, or array-like) – distributed resistance, in Ohm/m
  • G (number, or array-like) – distributed conductance, in S/m


if C,I,R,G are vectors they should be the same length

DistributedCircuit is Media object representing a transmission line mode defined in terms of distributed impedance and admittance values.

A Distributed Circuit may be defined in terms of the following attributes,

Quantity Symbol Property
Distributed Capacitance \(C^{'}\) C
Distributed Inductance \(L^{'}\) L
Distributed Resistance \(R^{'}\) R
Distributed Conductance \(G^{'}\) G

The following quantities may be calculated, which are functions of angular frequency (\(\omega\)):

Quantity Symbol Property
Distributed Impedance \(Z^{'} = R^{'} + j \omega L^{'}\) Z
Distributed Admittance \(Y^{'} = G^{'} + j \omega C^{'}\) Y

The properties which define their wave behavior:

Quantity Symbol Method
Characteristic Impedance \(Z_0 = \sqrt{ \frac{Z^{'}}{Y^{'}}}\) Z0()
Propagation Constant \(\gamma = \sqrt{ Z^{'} Y^{'}}\) gamma()

Given the following definitions, the components of propagation constant are interpreted as follows:

\[ \begin{align}\begin{aligned}+\Re e\{\gamma\} = \text{attenuation}\\-\Im m\{\gamma\} = \text{forward propagation}\end{aligned}\end{align} \]

See also



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_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.