Interactive Mismatched Line


This is a demonstration of using IPythons interact function with some of skrf’s network creation methods.

As of IPython 2.0, the widgets in this notebook won’t show up on To view the widgets and interact with them, you will need to download this notebook and run it with an IPython Notebook server.

from IPython.display import YouTubeVideo
YouTubeVideo('JyYi_1SswXs',width=700, height=580)

from ipywidgets import interact
%matplotlib inline
from pylab import *

from import DistributedCircuit
from skrf import Frequency
import skrf as rf

# define a frequency object
freq = Frequency(0,10,1001,'GHz')

# create a Media object for RG-58, based on distributed ckt values
rg58 = DistributedCircuit(frequency = freq,
                          C =93.5e-12,#F/m
                          L =273e-9,  #H/m
                          R =0,#53e-3,   #Ohm/m
                          G =0,       #S/m

Mismatched Line

This demonstrates the response of a mismatched transmission line of a given length. Specifically, a line of electrical length \(d\) with characteristic impedance \(z_0\) is embedded in the coaxial environment (RG-58 ) with \(z_0 \approx 54 \Omega\). The resultant S-parameters are plotted in log mag and on the smith chart.

Log Mag

def func(d=180,z0=54):
    ntwk =rg58.line(d=d,unit='deg',z0=z0)

interact(func, d= (0,360,10),z0=(10,200,1),embed=True);

Smith Chart


def func(d=180,z0=54): ntwk =rg58.line(d=d,unit='deg',z0=z0) ntwk.renormalize(rg58.z0) ntwk.plot_s_smith(1,0) ntwk.plot_s_smith(0,0) draw();show() interact(func, d= (0,180,10),z0=(10,200,1),embed=True);
[ ]: