Sources and Ports

rfx separates sources from ports:

sources inject fields without impedance loading
ports add an impedance model for S-parameter style workflows

Waveforms

Waveform	Signature	Use
`GaussianPulse`	`GaussianPulse(f0, bandwidth=0.5, amplitude=1.0)`	default wideband excitation
`ModulatedGaussian`	`ModulatedGaussian(f0, bandwidth=0.5, amplitude=1.0, cutoff=5.0)`	resonance work with reduced DC content
`CWSource`	`CWSource(f0, amplitude=1.0, ramp_steps=50)`	steady-state field visualisation
`CustomWaveform`	`CustomWaveform(func)`	JAX-compatible custom excitation

Sources

sim.add_source((0.025, 0.025, 0.010), "ez", waveform=GaussianPulse(f0=3e9))
sim.add_polarized_source((0.025, 0.025, 0.010), polarization="rhcp")

Use add_source() for ringdown and Harminv work when you do not want a load on the excited cell.

Ports

Method	Public role
`add_port(...)`	recommended lumped/wire port path for many RF examples
`add_waveguide_port(...)`	rectangular waveguide modal workflows
`add_msl_port(...)`	specialized microstrip-line S-matrix workflow
`add_coaxial_port(...)`	coaxial transmission-line reflection workflow via `compute_coaxial_line_reflection(...)`
`add_lumped_rlc(...)`	lumped network element at a cell

sim.add_port((0.01, 0.02, 0.01), "ez", impedance=50.0)
sim.add_port((0.01, 0.02, 0.0), "ez", impedance=50.0, extent=0.0016)
sim.add_coaxial_port((0.02, 0.02, 0.0016), face="top", impedance=50.0)
sim.add_waveguide_port(x_position=0.01, y_range=(0.0, 0.023), z_range=(0.0, 0.010))

S-parameter calculators

Use the calculator that matches the port family:

Primitive	Calculator
lumped/wire `add_port(...)`	`run(compute_s_params=True)`
lumped/wire `add_port(...)` in differentiable objectives	`forward(port_s11_freqs=...)`
`add_msl_port(...)`	`compute_msl_s_matrix()`
`add_waveguide_port(...)`	`compute_waveguide_s_matrix()`
`add_coaxial_port(...)`	`compute_coaxial_line_reflection(...)` for bounded one-port line reflection

run(compute_s_params=True) is not a universal port dispatcher. MSL, waveguide, and coaxial-line workflows use specialized calculators.

Before launching a long run, call the S-parameter preflight for the calculator you intend to use:

sim.preflight_sparameters(calculator="run")
sim.preflight_sparameters(calculator="msl")
sim.preflight_sparameters(calculator="waveguide")
sim.preflight_sparameters(calculator="forward")

Public boundary rules

Use sources for clean transient or resonance extraction.
Use ports when you need impedance-normalized outputs.
Use non-uniform workflows only with the relevant guide and validation checks.
Use coaxial line reflection only inside its documented envelope.
Advanced mixed-port workflows require a documented support entry before they are used in public examples.