Noting that Z L is a complex number in the form of r+j y, you can manipulate the equation for Z L to determine that a locus of points representing constant resistance is a circle of radius 1/( r+1) centered at r/( r+1). In a Smith chart, resistance (red) and reactance (blue) are plotted on a grid representing Γ. You’ll also see it represented as the scattering parameter S 11. It’s the reflection coefficient (sometimes denoted as ρ), which we discussed in part 1. Normalization lets one Smith chart work with any characteristic impedance. This part elaborates on the Smith chart’s construction and provides an impedance-matching example. Part 1 of this FAQ looked at why you might use a Smith chart. The Smith chart remains valuable in helping to visualize how such circuits perform. A typical RF/microwave circuit includes a source, transmission line, and load. That circuit includes a source with impedance Z s, transmission line with characteristic impedance Z 0, and load with impedance Z L. Take a journey around a Smith chart to find capacitance and inductance values in a matching network.īefore computers became ubiquitous, the Smith chart simplified calculations involving the complex impedances found in RF/microwave circuits such as the one shown in Figure 1.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |