skrf.media.Media

class skrf.media.Media(frequency=None, z0=None)

Abstract Base Class for a single mode on a transmission line media.

This class init’s with frequency and z0 (the port impedance); attributes shared by all media. Methods defined here make use of the properties :

• gamma - (complex) media propagation constant

• Z0 - (complex) media characteristic impedance

Which define the properties of a specific media. Any sub-class of Media must implement these properties. gamma and Z0 should return complex arrays of the same length as frequency. gamma must follow the convention:

• positive real(gamma) = attenuation

• positive imag(gamma) = forward propagation

Parameters

• frequency (Frequency object or None) – frequency band of this transmission line medium. Defaults to None, which produces a 1-10ghz band with 101 points.

• z0 (number, array-like, or None) – the port impedance for media. Only needed if its different from the characteristic impedance of the media. If z0 is None then will default to Z0. Default is None.

Notes

The z0 parameter (port impedance) is needed in some cases. RectangularWaveguide is an example where you may need this, because the characteristic impedance is frequency dependent, but the touchstone’s created by most VNA’s have z0=1 or 50. So to prevent accidental impedance mis-match, you may want to manually set the z0.

Attributes

Z0
alpha	Real (attenuation) component of gamma.
beta	Imaginary (propagating) component of gamma.
gamma	Propagation constant.
npoints	Number of points of the frequency axis.
v_g	Complex group velocity (in m/s).
v_p	Complex phase velocity (in m/s).
z0	Characteristic Impedance.

Methods

__init__
attenuator	Ideal matched attenuator of a given length.
capacitor	Capacitor.
copy	Copy of this Media object.
delay_load	Delayed load.
delay_open	Delayed open transmission line.
delay_short	Delayed Short.
electrical_length	Calculate the complex electrical length for a given distance.
extract_distance	Determines physical distance from a transmission or reflection Network.
get_array_of
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 (\(\Gamma_0 = 1\)).
plot
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	Convert 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.