hfsynpy 0.1.3

A Python library for synthesis and analysis of high frequency component (currently only microstrip transmission lines), providing accurate models and convenient tools for PCB and RF design.

hfsynpy

A modern Python package for high-frequency (HF) microstrip synthesis and analysis, inspired by the models used in KiCad. This library provides accurate, user-friendly tools for PCB and RF design, supporting both synthesis (width/length for target impedance and angle) and analysis (impedance, losses, phase shift for given geometry).

See the full documentation for all parameters, advanced usage, and API details.

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Features

• Synthesize microstrip width for a target impedance and electrical angle (input in degrees)
• Analyze microstrip properties for a given width and physical length (input in meters)
• Returns all results as well-documented dataclasses
• Outputs attenuation per meter (dB/m), effective permittivity, skin depth, and more
• Computes and returns phase shift (angle in degrees) for a given length
• No external dependencies required
• Well-documented, pip-installable, and tested

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Installation

pip install hfsynpy

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Quick Start

Synthesize Microstrip for Target Impedance and Angle

from hfsynpy import synthesize_microstrip

# Synthesize width for target Z0 using the functional API
syn_result = synthesize_microstrip(
    eps_r=3.66,  # Relative permittivity (3.66)
    tand=0.0037,  # Loss tangent (0.0037)
    h=1.524e-3,  # Substrate height (1.524 mm)
    t=35e-6,  # Copper thickness (35 um)
    rough=0e-6,  # Surface roughness (0 um)
    sigma=1 / (1.72e-8),  # Copper conductivity (5.814e7 S/m)
    mur=1.0,  # Relative permeability (substrate, 1.0)
    murc=1.0,  # Relative permeability (conductor, 1.0)
    frequency=2.45e9,  # Frequency (2.45 GHz)
    z0_target=50.0,  # Target impedance (50 ohms)
    ang_l_target=30.0,  # Target angle for length synthesis (degrees)
)
print("Synthesis result:")
print(f"Synthesized width: {syn_result.width * 1e3:.4f} mm")
print(f"Effective permittivity: {syn_result.epsilon_eff:.4f}")
print(f"Skin depth: {syn_result.skin_depth * 1e6:.4f} um")
print(f"Conductor attenuation: {syn_result.atten_cond:.4f} dB/m")
print(f"Dielectric attenuation: {syn_result.atten_diel:.4f} dB/m")
print(f"Physical length: {syn_result.length * 1e3:.4f} mm")

Analyze Microstrip for Given Width and Length

from hfsynpy import analyze_microstrip

# Analyze for a specific width using the functional API
ana_result = analyze_microstrip(
    width=0.79e-3,  # 0.79 mm
    eps_r=3.66,
    tand=0.0037,
    h=1.524e-3,
    t=35e-6,
    rough=0e-6,
    sigma=1 / (1.72e-8),
    mur=1.0,
    murc=1.0,
    frequency=2.45e9,
    length=50e-3,  # 50 mm
)
print("\nAnalysis result:")
print(f"Characteristic impedance: {ana_result.Z0_0:.4f} ohms")
print(f"Effective permittivity: {ana_result.epsilon_eff:.4f}")
print(f"Skin depth: {ana_result.skin_depth * 1e6:.4f} um")
print(f"Conductor attenuation: {ana_result.atten_cond:.4f} dB/m")
print(f"Dielectric attenuation: {ana_result.atten_diel:.4f} dB/m")
print(f"Angle shift: {ana_result.angle_deg:.4f} degrees")

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API Overview

synthesize_microstrip(...)

• Synthesize width for target impedance and angle (degrees)
• Returns: MicrostripSynthesisResult dataclass

analyze_microstrip(...)

• Analyze for given width and length (meters)
• Returns: MicrostripAnalysisResult dataclass (includes angle_deg if length is given)

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License

This project is licensed under the GNU General Public License v2 or later (GPL-2.0-or-later). See the LICENSE file for details.

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Attribution

This package is part of a Python translation of KiCad's C++ source code.

Original C++ code:

• © 2001 Gopal Narayanan [e-mail]
• © 2002 Claudio Girardi [e-mail]
• © 2005, 2006 Stefan Jahn [e-mail]
• Modified for KiCad: 2018 Jean-Pierre Charras <jp.charras at wanadoo.fr>
• © The KiCad Developers, see AUTHORS.txt for contributors.

Python translation and modifications:

• © 2025 Dominik Mair [e-mail]

This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version.

This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.

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For bug reports, feature requests, or contributions, please use the GitHub repository.