MICROWAVE MEASUREMENT 3.4.1 Smith Chart Parameters Smith chart consists of transmission line parameters such as normalized impedance, Zβ (the most common) or normalized admittance, Yβ or both. The normalized parameters are constructed on the complex reflection coefficient plane in two dimensions, that is using rectangular (i,j) and polar (r,Ο΄) scale. Normalized scaling allows the Smith chart to be used for problems involving various characteristic impedance /admittance for various transmission line or systems. Figure 3.4.1 shows separately the Smith Chart parameters that are: (a) the normalized resistances circles, where the value of the circles is shown by the horizontal line begin with 0 on the left of the green line and increasing to the right. (b) the normalized reactance curves, where the value of the curve is shown at the edge of the circle; i. half circle in red to represent pure inductive reactance + jxL(pure inductive susceptance, + jbL) ii. half circle in blue to represesny pure capacitive raectance -jxC (pure capacitive susceptance, - jbC)
(a)
(b) Figure 3.4.1: Elemen of Smith Chart - (a) Sets of normalized resistance(r)/conductance(g), and (b) set of normalized reactance(x)/susceptance(b) that touch at a point on the righthand side Page 19
