ABSTRACT
Two-port equivalent circuits are widely used in RF and microwave circuit design to describe the electrical behavior of both active devices and passive networks [1,2]. The twoport network impedance Z-parameters, admittance Y-parameters, or hybrid H-parameters are very important to characterize the nonlinear properties of any type of bipolar or eld-effect transistors used as an active device of the power amplier. The transmission ABCD-parameters of a two-port network are very convenient for designing the distributed circuits such as transmission lines or cascaded active or passive elements. The scattering S-parameters are useful to characterize linear circuits and are required to simplify the measurement procedure. Transmission lines are widely used in matching networks of high-power or low-noise ampliers, directional couplers, power combiners, and power dividers. Monolithic implementation of lumped inductors and capacitors is usually required at microwave frequencies and for portable devices.
