Public Documentation

smithplot(z; kwargs...)

Plot lines on the Smith Chart.

Valid Keywords:

• color sets the color of the marker. Read ? scatter.
• colormap = :viridis sets the colormap that is sampled for numeric colors.
• linestyle = :rect sets the pattern of the line e.g. :solid, :dot, :dashdot.
• line_width = 2.8 sets the width of the line in pixel units.
• label = nothing
• reflection = false: Specifies whether it is a normalized impedance or a reflection coefficient.
• freq = Float64[] Array of frequencies associated with each represented value. Mainly used by DataInspector.

Examples

using SmithChart
using CairoMakie

fig = Figure(size = (800, 600))
sc = SmithAxis(fig[1, 1], cutgrid = true)
r = 0.6 .+ 0.15 * exp.(1im .* range(0, 2π; length = 300))
smithplot!(sc, r; color = :dodgerblue, linewidth = 2)
fig

```

smithscatter(z; kwargs...)

Scatter points on the Smith Chart.

Valid Keywords:

• color sets the color of the marker. Read ? scatter.
• colormap = :viridis sets the colormap that is sampled for numeric colors.
• marker = :rect sets the scatter marker.
• markersize = 9 sets the size of the marker.
• label = nothing
• reflection = false: Specifies whether it is a normalized impedance or a reflection coefficient.
• freq = Float64[] Array of frequencies associated with each represented value. Mainly used Mainly used by DataInspector.

Examples

using SmithChart
using CairoMakie

fig = Figure(size = (800, 600))
sc = SmithAxis(fig[1, 1], cutgrid = true)
r = 0.6 .+ 0.15 * exp.(1im .* range(0, 2π; length = 300))
smithscatter!(sc, r; color = :dodgerblue, linewidth = 2)
fig

vswr(v; args...)

Plots reflection data on a Smith chart, configured to visualize Voltage Standing Wave Ratio (VSWR) characteristics.

This function is a convenience wrapper around smithplot, with the keyword reflection = true set by default. It is intended for use when plotting reflection coefficients or S-parameter data, where impedance normalization is not needed.

Arguments

• v: VSWR value
• args...: Additional keyword arguments forwarded to smithplot, allowing customization of plot appearance and behavior.

Example

vswr(2.0; color = :red, linewidth = 2)

This plots a VSWR = 2 circle centered at the origin with radius 1/3.

See also: smithplot, smithscatter

datamarkers(ax::SmithAxis, gp::GridPosition, priority = 100; fontsize = 10.0, title = true, kwargs...)

Allows creating data markers with double click on the lines or scatter plots.

Arguments

• ax::SmithAxis is the SmithAxis.
• gp::GridPosition is a GridPosition. Example: fig[1,2]
• markerdict::Dict{Int, ComplexF64} is a Dict that stores the data of each marker. If you don't need

the values you can ignore this argument.

Examples

using SmithChart
using GLMakie

fig = Figure(size = (800, 600))
sc = SmithAxis(fig[1, 1], cutgrid = true)
r = 0.6 .+ 0.35 * cis.(range(0, 2π; length = 300))
smithplot!(sc, r; color = :dodgerblue, linewidth = 2)
datamarkers(sc, fig[1,2])
fig

NFCircle(F, Fmin, Γopt, Rn, Zo)

Computes the points of the constant Noise Figure Circle.

Arguments

• F: noise factor
• Fmin: minimum noise factor
• Γopt: optimimum source reflection coefficient related to Zopt or Yopt.
• Rn: noise resistance parameter
• Zo: Reference Impedance
• Np: Number of points

Example

using SmithChart

NF_to_F(nf) = 10.0^(nf/10.0)
Γopt = 0.5 * cis(130 * pi / 180)
NFmin = 1.6 # dB
Fmin = NF_to_F(NFmin)
F2dB = NF_to_F(2.0)
nf2 = NFCircle(F2dB, Fmin, Γopt, 20.0, 50.0, 361)

CGCircle(gi, Sii)

Computes the points of the Constant Gain Circle.

Arguments

• gi: It's gsource or gload and it's value is G / Gmax
• Sii: Reflection S parameter. S11 for Gs and S22 for Gl.
• Np: Number of points

Example

using SmithChart

S11 = 0.533 * cis(176.6 / 180 * π)
Gs_max = 1 / (1 - abs2(S11))
gain(dB) = 10.0^(dB/10.0)
g1 = gain(0.0) / Gs_max
c1 = CGCircle(g1, S11, 361)

StabilityCircle(S11, S12, S21, S22, inout::Symbol, Np; stable = false)

Computes the region of stability (or unstability) and returns a Makie.Polygon.

Arguments

• Sii: S-parameter
• inout: a symbol selecting source or load regions. Valid values are :load or :source.
• Np: Number of points.
• stable: Selects if the region corresponds to the stable (true) or unstable (false) region.

Examples

using SmithChart

S11, S12, S21, S22 =  [0.438868-0.778865im 1.4+0.2im; 0.1+0.43im  0.692125-0.361834im]
A =  StabilityCircle(S11, S12, S21, S22, :source, 361; stable = false)