Plotting microstrip impedance vs width using UliEngineering

#!/usr/bin/env python3
from UliEngineering.Electronics.Microstrip import microstrip_width
from UliEngineering.EngineerIO import format_value
from UliEngineering.EngineerIO.Length import convert_length_to_unit

# Compute the width for a 50 Ω microstrip using string args with units
w = microstrip_width("50 Ω", h="150 um", t="35 um", e_r="4.4")
# Convert result (meters) to mils and print
w_mil = convert_length_to_unit(w, "m", "mil")
print(format_value(w_mil, "mil"))

#!/usr/bin/env python3
import numpy as np
import matplotlib.pyplot as plt
from matplotlib.ticker import FuncFormatter, AutoMinorLocator

# UliEngineering imports
from UliEngineering.Electronics.Microstrip import microstrip_impedance
from UliEngineering.EngineerIO import format_value
from UliEngineering.EngineerIO.Length import normalize_length

# Constants
e_r = 4.4
thicknesses = ["100um", "150um", "200um", "1550um"]
# Copper thickness (defaulting to 35um as it wasn't specified but is required for calculation)
t_copper = "35um"

# Width axis: 1mil to 10mm linear
w_min = normalize_length("1mil")
w_max = normalize_length("10mm")
# For a log x-axis we need widths spaced logarithmically; use np.logspace
widths = np.logspace(np.log10(w_min), np.log10(w_max), 1000)

# Plotting
plt.style.use("ggplot")
fig, ax = plt.subplots(figsize=(10, 12))

# Generate colors
colors = plt.cm.viridis(np.linspace(0, 1, len(thicknesses)))

for h_str, c in zip(thicknesses, colors):
    # Calculate impedance for each width
    # microstrip_impedance uses math functions so it doesn't support numpy arrays directly
    zs = [microstrip_impedance(w, h=h_str, t=t_copper, e_r=e_r) for w in widths]
    
    ax.plot(widths, zs, color=c, lw=2, label=f"h={h_str}")

# Add a legend
legend = ax.legend(loc='upper right', fontsize='small')

ax.set_xscale("log")
ax.set_xlabel("Width (log scale)")
ax.set_ylabel("Impedance")
ax.set_title(rf"Microstrip Impedance vs Width ($\epsilon_r={e_r}$)")
ax.grid(True, which="both", ls="--")

# Axis formatters using EngineerIO format_value
ax.xaxis.set_major_formatter(FuncFormatter(lambda x, pos: format_value(x, "m")))
ax.yaxis.set_major_formatter(FuncFormatter(lambda y, pos: format_value(y, "Ω")))

# Enable minor ticks and add minor tick labels on the Y axis
ax.minorticks_on()
# For linear scale, AutoMinorLocator is usually good, or we can let matplotlib handle it.
# The template used LogLocator, but we are linear.
ax.yaxis.set_minor_locator(AutoMinorLocator())
ax.yaxis.set_minor_formatter(FuncFormatter(lambda y, pos: format_value(y, "Ω")))

# Style minor tick labels: 30% smaller and 70% gray
maj_ylabels = ax.yaxis.get_ticklabels(which='major')
if len(maj_ylabels) > 0:
    base_size = maj_ylabels[0].get_size()
else:
    base_size = plt.rcParams.get('ytick.labelsize', plt.rcParams.get('font.size', 10))
ax.tick_params(axis='y', which='minor', labelsize=base_size * 0.7, labelcolor='0.7', colors='0.7')

# Also set x-axis minor ticks and style them with smaller rotated labels
from matplotlib.ticker import LogLocator
ax.xaxis.set_minor_locator(LogLocator(base=10.0, subs=(2, 3, 4, 5, 6, 7, 8, 9)))
ax.xaxis.set_minor_formatter(FuncFormatter(lambda x, pos: format_value(x, "m")))

maj_xlabels = ax.xaxis.get_ticklabels(which='major')
if len(maj_xlabels) > 0:
    base_x_size = maj_xlabels[0].get_size()
else:
    base_x_size = plt.rcParams.get('xtick.labelsize', plt.rcParams.get('font.size', 10))
ax.tick_params(axis='x', which='minor', labelsize=base_x_size * 0.7, labelcolor='0.7', colors='0.7')

for tl in ax.get_xminorticklabels():
    tl.set_rotation(90)
for tl in ax.get_xmajorticklabels():
    tl.set_rotation(90)

fig.tight_layout()
plt.show()
plt.savefig("Microstrip-Impedance.svg")