Connor RPI ECSE DepartmentĬonstant Reflection Coefficient Circle Scale in Wavelengths Toward Generator Away From Generator Full Circle is One Half Wavelength Since Everything Repeats K. The distance moved on the line is indicated on the outside of the chart in wavelengths K.

Rotate clockwise to move toward the generator (away from the load)

Any point on the line is found on this circle.

The circle passes through the normalized load impedance The center of the circle is the center of the chart.

Next, a circle is drawn that represents the reflection coefficient or SWR.

Thus, the first step in analyzing a transmission line is to locate the normalized load impedance on the chart.

Impedance divided by line impedance (50 Ohms).

Impedance Z=R+jX =100+j50 Normalized z=2+j for Zo=50 Smith Chart Constant Imaginary Impedance Lines Constant Real Impedance Circles K. Imaginary Impedance Axis Smith Chart Real Impedance Axis K.

The combination of intersecting circles inside the chart allow us to locate the normalized impedance and then to find the impedance anywhere on the line K.

The outside of the chart shows location on the line in wavelengths.

The Smith Chart is a clever tool for analyzing transmission lines.

all still have the same properties, but the results can be generalized to any line with the same normalized impedances K.

If the load impedance is normalized by the characteristic impedance of the line, the voltages, currents, impedances, etc.

The magnitude of the reflection coefficient, the standing wave ratio (SWR) do not change, so they characterize the voltage & current patterns on the line.Smith Chart Supplemental Information Fields and Waves I ECSE 2100 K.

Smith chart applet