Smith Chart
Plot a complex load impedance on a Smith chart and calculate normalized impedance, reflection coefficient, SWR and return loss.
Interactive starting-point Smith chart. Enter a load impedance and the tool plots its normalized impedance and reflection coefficient. Use the point to reason about matching networks or transmission-line transformations.
Read impedance on the chart
A Smith chart is a graphical impedance and admittance map. It becomes most useful when you need to understand how a load changes as you move along a transmission line or add a matching element.
Normalize the impedance to the characteristic impedance before plotting. A load that looks very different numerically can occupy the same position on the chart after normalization to a different reference impedance.
Use the chart to understand the direction of a matching transformation, then verify the final network with an analyser or simulation. Real components have loss and parasitics that an ideal chart does not show.
Use the chart to choose a matching approach
A Smith Chart is most useful when it turns a complex impedance into a visual matching problem. The chart normally works with impedance or admittance normalized to a chosen reference resistance, commonly 50 ohms. A point to the right or left of the centre represents a resistive component, while movement above or below the horizontal axis represents reactance. Constant-resistance and constant-reactance circles then show how a load changes as matching elements or transmission-line sections are introduced. The chart is not a substitute for a measurement: the plotted point is only as accurate as the impedance values supplied to it. Cable loss, connector discontinuities and frequency-dependent component behaviour can change the real installation. For practical work, compare the calculated point with an analyser measurement at the same reference plane and frequency. That makes the chart a design and troubleshooting aid rather than a purely theoretical drawing.
Next step in the workflow
Use the calculation as a starting point, then move to the tool that answers the next practical question.