Plot S11 data

plot_touchstone_file.py

# Create a Smith Chart and plot the contents of a .s1p file
import numpy as np
import skrf as rf
from matplotlib import rcParams, pyplot as plt
import sys
from mpl_smithchart import SmithAxes

# output settings
out_title = "Smith Chart Output"

# set the default filename
fname1 = 'test.s1p'

# check if there is any command line filename
if len(sys.argv) == 2:
    fname1 = sys.argv[1]

print(f'Opening file: {fname1}')

ntwk1 = rf.Network(fname1)
sdata = ntwk1.s
sdata = sdata.reshape(sdata.shape[0])

# customize the Smith Chart functionality here:
SmithAxes.update_scParams(plot_marker_start='x', plot_marker_end='x', plot_marker_hack=True)

# create a figure and Smith Chart
plt.figure(figsize=(10,10)).set_layout_engine('tight')
ax = plt.subplot(111, projection='smith')

# plot the data
plt.plot(sdata, markevery=5, label="trace1", datatype=SmithAxes.S_PARAMETER)

# final decorations
legend = plt.legend(loc="lower right", fontsize=12)
plt.title(out_title, fontsize=18)

# save the plot to a file
plt.savefig("export.png", format="png")

# display the plot
plt.show()