Graphical Determination of Two-Port Properties by the Bilinear Pole-Zero Method,

By locating the principle pole and zero of the relevant bilinear function and utilizing some lesser known theorems in Euclidean geometry a simple method is outlined for the evaluation of common design formulas for active bilateral two-port networks. The method is particularly suitable where simultaneous criteria involving power gain, voltage gain or other transfer ratios, stability or impedance level, must be satisfied in the presence of a variable parameter. Various transformations and their merits are outlined, one of the most important being a method for employing the Smith chart in the above evaluations. The relationship of this method to known Euclidean graphical procedures, e.g., the image circle and the Linvill chart is given, indicating these to be special cases within the more general theory.