skrf.media.Media

class skrf.media.Media(frequency=None, z0_port=None, z0_override=None, z0=None)

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

This class init’s with frequency and z0_port (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_port (number, array-like, or None) – z0_port is the port impedance for networks generated by the media. If z0_port is not None, the networks generated by the media are renormalized (or in other words embedded) from the characteristic impedance z0 of the media to z0_port. Else if z0_port is None, the networks port impedances will be the raw characteristic impedance z0 of the media. (Default is None)

• z0_override (number, array-like, or None) – z0_override override the characteristic impedance for the media. If z0_override is not None, the networks generated by the media have their characteristic impedance z0 overrided by z0_override. (Default is None)

• z0 (number, array-like, or None) – deprecated parameter, alias to z0_override if z0_override is None. Emmit a deprecation warning.

Notes

Full-wave simulations results can be networks with complex and frequency-dependant z0 port impedances. However, the regular touchstone (s-parameters) files generated by most VNA measurements are normalized to a single real value, e. g. 1. or 50 ohm. Manually setting the z0_port to a single real value enforce the second behaviour. The default (z0_port = None) is the first behaviour.

Attributes

Z0	Characteristic Impedance
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	Return Characteristic Impedance z0_characteristic.
z0_characteristic	Characteristic Impedance, \(z_0\).
z0_override	Port Impedance.
z0_port	Port Impedance.

Methods

__init__
attenuator	Ideal matched attenuator of a given length.
capacitor	Capacitor.
capacitor_q	Capacitor with Q factor.
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.
inductor_q	Inductor with Q factor.
isolator	Two-port isolator.
line	Transmission line of a given length and impedance.
line_floating	Floating 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.
shunt_resistor	Shunted resistor.
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.