S-Parameters › Smith Chart
Smith Chart — Plotter, Auto-Match & Network Calculator
Three tools in one page. ① Plotter: upload Touchstone or manually enter impedance points. ② Matching Designer: explore manually or hit Auto-Solve for instant L/pi/T component values. ③ Network Calculator: enter Z_source and Z_load, get every topology's component values immediately.
Reference Impedance
Ω
Add Impedance Point
Ω
Ω
Touchstone S11 Trace
Drop .s1p / .s2p here
or click to browse
or click to browse
Hover / Selected Readout
Impedance
—
|Γ|
—
VSWR
—
Return Loss
—
Γ Phase
—
Plotted Points
No points plotted yet
// Smith Chart — Z₀ = 50 Ω · hover to read values
Constant R circles
Constant X arcs
Points
S11 trace
// Key Formulas
Γ = (Z−Z₀)/(Z+Z₀) · Z = Z₀·(1+Γ)/(1−Γ)
VSWR = (1+|Γ|)/(1−|Γ|) · RL = −20·log₁₀|Γ| dB
Upper half = Inductive (+jX) · Lower half = Capacitive (−jX)
VSWR = (1+|Γ|)/(1−|Γ|) · RL = −20·log₁₀|Γ| dB
Upper half = Inductive (+jX) · Lower half = Capacitive (−jX)
1 — Load Impedance & Frequency
Ω
2 — Current Impedance
Z (after all steps)
—
|Γ| = — · VSWR = — · RL = —
Distance to centre
|Γ| = —
⚡ Auto-Solve — L-Network Solutions
Computes all valid 2-element L-network solutions analytically. Click any solution to load it into the designer.
3 — Add Element Manually
nH
4 — Matching Steps
No elements yet — use Auto-Solve or add manually.
Manual mode: Series L/C moves along constant-R circles. Shunt L/C moves along constant-G circles. TL section rotates Γ clockwise. Dashed preview arc shows where next element will take you.
Smith Chart Matching Designer — Z₀ = 50 Ω
Z_load
Matching path
Z_now
Target (Z₀)
Auto-solve paths
Matching Network Summary
Add elements or use Auto-Solve to see the network summary.
Smith Chart Movement Rules
Series L (+jX): UP along constant-R circle (inductive)
Series C (−jX): DOWN along constant-R circle (capacitive)
Shunt L (−jB): DOWN along constant-G circle (admittance plane)
Shunt C (+jB): UP along constant-G circle (admittance plane)
TL section: rotates Γ CLOCKWISE around centre
Target = chart centre: Z = Z₀, |Γ| = 0, VSWR = 1:1
Source & Load Impedance
Q
Ω
Impedance Ratio
L-network: exact 2-element match — Q is set by the impedance ratio (cannot be chosen freely). Works only when one impedance is larger than the other.
Pi/T network: 3-element match — Q is a free design parameter. Higher Q → narrower bandwidth but better harmonic rejection. Q must exceed Q_min = √(R_high/R_low − 1).
Pi/T network: 3-element match — Q is a free design parameter. Higher Q → narrower bandwidth but better harmonic rejection. Q must exceed Q_min = √(R_high/R_low − 1).
Enter impedances above to compute matching networks.