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Using TSmithChart


The TSmithChart component is inherited from the TRChart component and is thus closely related to it. Many of the methods and properties of TSmithChart are similar or even euqual to their counterparts in TRChart. Thus we describe here only thoses properties and methods which differ from TRChart. Please refer to the section on How to Use RChart for further information on the common features.

TSmithChart is a little bit simpler as it does not support more than one data layer nor does is provide more than one crosshair. In additon, some of the more elaborate graphics elements (such as the 3D bars) of TRChart are also not available.

The coordinates of the circular chart are in the range between [-1,-1] and [+1,+1] since the chart coordinates are the real and imaginary part of the complex reflection coefficient:

However, there exist several methods to convert between the complex reflection coefficient and (normalized) complex impedances: CalcResistance and CalcReactance calculate the resistance (real part of the line impedance) and the reactance (imaginary part of the line impedance), respectively. The inverse conversion from the impedance to the reflection coefficient can be performed by the methods CalcReflectionReal and CalcReflectionImag.

The colors of the chart are similar to the RChart implementation with one specific exception: DiagramColor controls the color of the Smith chart (i.e. the circle of the definition range of the complex reflection coefficient). Further, TSmithChart is always isometric to guarantee that the displayed diagram stays circular, which has an effect on the setting the chart range. The most notably one is that the property RangeYHigh is read-only (the magnification of the chart is controlled by the properties RangeXLow and RangeXHigh, the range along the y-axis is adjusted automatically to ensure isometric behavior). The method CenterChart can be used to shift the chart to the center of the chart window.


Last Update: 2013-May-14