AN 958: Board Design Guidelines

ID 683073
Date 6/26/2023
Document Table of Contents

5.6. Smith Chart

The Smith Chart is a graphical representation of the impedances in a complex plane. You can use this to analyze transmission line impedance matching networks and capacitive or inductive behavior of loads. Figure 88 shows a typical Smith Chart. If the impedance is inductive, it shows up in the top half of the circle; if it is capacitive, it shows up in the bottom half. The far-right point in the middle represents an open circuit; the far left represents a short circuit. The middle point (label 1.0) represents a perfect load match to the characteristic impedance of the line.

Figure 88. Smith Chart