skrf.media.media.Media

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

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) propgation constant
  • Z0 - (complex) characteristic impedance

Which define the properties of 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) – frequency band of this transmission line medium. If None, will default to 1-10ghz,
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

Notes

The z0 parameter 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
v_g Complex group velocity (in m/s)
v_p Complex phase velocity (in m/s)
z0

Methods

__init__ Initialize self.
attenuator Ideal matched attenuator of a given length
capacitor Capacitor
copy
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
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 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.