The horizontal axis represents resistance (R): positive to the right of the origin and negative to the left.
Positive resistance which represents loss is on the positive X axis. Inductive reactance is positive (+Y axis) and capacitive reactance is negative (-Y axis). The X axis represents resistance (R) and the Y axis represents reactance (X). This graph shows the rectangular coordinates for any impedance. Graphically, these components are represented as a pair of axes at right angles, as in Figure 1.įIGURE 1. All impedances consist of resistance and reactance. The ARRL has made the QST articles available for downloading at Where Does the Smith Chart Come From?īefore discussing the chart, let’s back up a step. You can read these articles first or use them as references throughout this article. They provide as much background as you care to absorb, and deeper discussions than this article can provide. First described by Phillip Smith in 1939, there are a number of QST articles and a detailed Wikipedia page ( en./wiki/Smith_chart) on the Smith Chart.
