# qpdk > QPDK is an open-source process design kit (PDK) for superconducting quantum RF applications built on gdsfactory. It provides parametric quantum circuit components (transmon qubits, CPW resonators, Josephson junctions, etc.), analytical S-parameter models, routing utilities, and test-chip examples. Source: https://github.com/gdsfactory/quantum-rf-pdk; published as `qpdk` on PyPI. gdsfactory ## Pages - [QPDK — Superconducting Quantum Process Design Kit](https://gdsfactory.github.io/quantum-rf-pdk/index.html.md): QPDK, an open-source gdsfactory process design kit for superconducting quantum RF circuits; overview, installation and key components. - [PCells](https://gdsfactory.github.io/quantum-rf-pdk/cells.html.md): Gallery and API reference for all QPDK layout components (qubits, resonators, couplers, routing, etc.). - [Models](https://gdsfactory.github.io/quantum-rf-pdk/models.html.md): S-parameter and circuit models for QPDK quantum RF components. - [Samples](https://gdsfactory.github.io/quantum-rf-pdk/samples.html.md): Example QPDK scripts that assemble components into full chip layouts. - [Notebooks](https://gdsfactory.github.io/quantum-rf-pdk/notebooks.html.md): Jupyter notebooks demonstrating simulation approaches for superconducting quantum devices. - [QPDK Models](https://gdsfactory.github.io/quantum-rf-pdk/notebooks/all_models.html.md): This notebook evaluates and plots a selection of the S-parameter models in `qpdk.models`. - [Circuit Simulation with QPDK](https://gdsfactory.github.io/quantum-rf-pdk/notebooks/circuit_simulation_demo.html.md): This notebook demonstrates how to perform circuit simulations using the `qpdk` models and the `sax` ... - [Differentiable Transmon Circuit Simulation with Circulax](https://gdsfactory.github.io/quantum-rf-pdk/notebooks/circulax_transmon_optimization.html.md): This notebook demonstrates how to use - [COMSOL Full-Wave Simulation of a Coupled Quarter-Wave Resonator](https://gdsfactory.github.io/quantum-rf-pdk/notebooks/comsol_cpw_resonator.html.md): The shortest path from a QPDK layout to a driven COMSOL result: build a coupled quarter-wave - [COMSOL transmon capacitance and field](https://gdsfactory.github.io/quantum-rf-pdk/notebooks/comsol_qubit_capacitance.html.md): This tutorial walks the path end to end: build a QPDK double-pad - [Elmer Capacitance Extraction of an Interdigital Capacitor](https://gdsfactory.github.io/quantum-rf-pdk/notebooks/elmer_capacitance_interdigital.html.md): This notebook runs a quasi-static electrostatic solve with Elmer FEM for two - [FEM Dataset Lookup in SAX Models](https://gdsfactory.github.io/quantum-rf-pdk/notebooks/fem_dataset_lookup.html.md): Circuit models of superconducting layouts need electrostatic quantities such as - [HFSS Driven Modal Simulation of an Interdigital Capacitor](https://gdsfactory.github.io/quantum-rf-pdk/notebooks/hfss_driven_capacitor.html.md): This notebook demonstrates how to set up and run a driven modal (S-parameter) - [HFSS Eigenmode Simulation of a CPW Resonator](https://gdsfactory.github.io/quantum-rf-pdk/notebooks/hfss_eigenmode_resonator.html.md): This notebook demonstrates how to set up and run an eigenmode simulation - [Q2D Cross-Section Impedance of a Coplanar Waveguide](https://gdsfactory.github.io/quantum-rf-pdk/notebooks/hfss_q2d_cpw_impedance.html.md): This notebook demonstrates how to extract the characteristic impedance - [JAX Backend Comparison for Quantum Circuit Simulation](https://gdsfactory.github.io/quantum-rf-pdk/notebooks/jax_backend_comparison.html.md): This notebook loads recorded CPU, CUDA, and Apple Silicon (MPS) measurements - [Josephson traveling-wave parametric amplifiers with JosephsonCircuits.jl](https://gdsfactory.github.io/quantum-rf-pdk/notebooks/josephsoncircuits_twpa.html.md): A traveling-wave parametric amplifier (TWPA) uses a chain of Josephson junctions to amplify a weak s... - [Call qpdk from MATLAB](https://gdsfactory.github.io/quantum-rf-pdk/notebooks/matlab_integration.html.md): This notebook demonstrates calling `qpdk` (and through it, `gdsfactory`) **directly from MATLAB** - [Model Comparison to Qucs-S](https://gdsfactory.github.io/quantum-rf-pdk/notebooks/model_comparison_to_qucs.html.md): This notebook compares the S-parameter models from qpdk (using sax) against reference - [Monte Carlo Fabrication Tolerance Analysis](https://gdsfactory.github.io/quantum-rf-pdk/notebooks/monte_carlo_fabrication_tolerance.html.md): This notebook demonstrates how to run a circuit-level SAX simulation of the - [Transmon Qubit Design with NetKet](https://gdsfactory.github.io/quantum-rf-pdk/notebooks/netket_transmon_design.html.md): This notebook demonstrates how to use - [Optuna Optimization of Interdigital Capacitor](https://gdsfactory.github.io/quantum-rf-pdk/notebooks/optimize_capacitor_optuna.html.md): This example demonstrates using Optuna to optimize an interdigital capacitor - [Dispersive Shift of a Transmon–Resonator System with Pymablock](https://gdsfactory.github.io/quantum-rf-pdk/notebooks/pymablock_dispersive_shift.html.md): This notebook demonstrates how to use - [Pulse-Level Simulation of Superconducting Qubits with QuTiP-QIP](https://gdsfactory.github.io/quantum-rf-pdk/notebooks/qutip_qip_pulse_simulation.html.md): This notebook demonstrates how to use - [Resonator frequency estimation models](https://gdsfactory.github.io/quantum-rf-pdk/notebooks/resonator_frequency_model.html.md): This example demonstrates estimating resonance frequencies of superconducting microwave resonators u... - [Dispersive Shift of a Transmon–Resonator System with scQubits](https://gdsfactory.github.io/quantum-rf-pdk/notebooks/scqubits_parameter_calculation.html.md): This notebook demonstrates how to use - [CPW parametric amplifiers: layout and circuit models](https://gdsfactory.github.io/quantum-rf-pdk/notebooks/vacask_cpw_parametric_amplifier.html.md): A flux-pumped JPA uses a SQUID to modulate the resonance of a distributed - [Lumped Josephson parametric amplifiers with VACASK](https://gdsfactory.github.io/quantum-rf-pdk/notebooks/vacask_lumped_parametric_amplifier.html.md): A parametric amplifier uses a strong pump and a nonlinear inductance to - [Simulation](https://gdsfactory.github.io/quantum-rf-pdk/simulation.html.md): Circuit-model hierarchy and field-solver simulation helpers for QPDK components. - [Contributing](https://gdsfactory.github.io/quantum-rf-pdk/contributing.html.md): We welcome contributions of all sizes—bug fixes, documentation, new components, and improvements to ... - [Customizing QPDK for Your Process](https://gdsfactory.github.io/quantum-rf-pdk/customizing.html.md): How to fork QPDK into a process-specific PDK and keep the fork current with upstream releases. - [Security Policy](https://gdsfactory.github.io/quantum-rf-pdk/security.html.md): We provide security fixes for the latest released version of this project. Older versions are not ac... - [Code of Conduct](https://gdsfactory.github.io/quantum-rf-pdk/code_of_conduct.html.md): We follow the gdsfactory - [Justfile Commands](https://gdsfactory.github.io/quantum-rf-pdk/just_commands.html.md): The repository includes a `justfile` with convenient commands for common development tasks. - [Makefile Compatibility](https://gdsfactory.github.io/quantum-rf-pdk/make_commands.html.md): A `Makefile` is provided as a thin compatibility layer for the ## Optional - [llms-full.txt](https://gdsfactory.github.io/quantum-rf-pdk/llms-full.txt): Complete documentation in a single file.