⚠️For educational purposes only — not a professional tool. Learn more
Smith Chart Impedance Tool
Interactive impedance matching tool: plot impedances, read reflection coefficient, VSWR and return loss, and get L-network component values.
Smith Chart
Use arrow keys to position the chart cursor and Enter or Space to plot. When a point is selected, use arrow keys to move it and Escape to deselect it.
Impedance Input
Quick Help
- Click anywhere to add a point
- Drag points to see real-time changes
- VSWR < 2 indicates good matching
- Center = Z0 (perfect match)
- Right side = high resistance
- Upper half = inductive
- Lower half = capacitive
Smith Chart User Guide
Interactive Features
- Click Plotting: Click anywhere on chart to select impedance point
- Manual Entry: Enter Z0, resistance and reactance for precise plotting
- Drag Interaction: Drag points to continuously update values
- Keyboard Plotting: Move the cursor with the arrow keys on the focused chart
- Circle Overlays: Toggle VSWR circles, reactance circles and labels
- Undo / Redo: Step back through plotted points
- Data Export: Save plotted points as a Touchstone (.s1p) file
Readouts and Matching
- Reflection Coefficient: Live impedance to Gamma conversion
- VSWR and Return Loss: Numerical values with colour coding
- L-Network Matching: Press Match to get series and shunt component values at your frequency
- Quality Factor: Q of the matching network
Smith Chart Navigation Guide
Chart Regions:
- Center: Perfect match (Z = Z0, Gamma = 0)
- Upper Half: Inductive reactance (+jX)
- Lower Half: Capacitive reactance (-jX)
- Left / Right Edge: Short circuit (Z = 0) / open circuit (Z = infinity)
- Outer Circle: Purely reactive loads (R = 0, |Gamma| = 1)
- Real Axis: Pure resistive impedances
Movement Patterns:
- Clockwise: Moving toward generator
- Counter-clockwise: Moving toward load
- Full Rotation: lambda/2 of line length
- Series Reactance: Moves along a constant-resistance circle
- Shunt Susceptance: Moves along a constant-conductance circle