The advancement of technology has made wireless communications ubiquitous, and thus they represent a major field of study nowadays. The demand for engineers able to design circuits and systems to operate in the microwave regime is increasing every day, and universities and graduate schools have to form them in the best possible way, giving them the abilities and competences needed to succeed in this field.

One of the motors for the fast development and evolution of wireless communications circuits and systems is the Metal-Oxide-Semiconductor-Field-Effect-Transistor (MOSFET or MOS Transistor). The MOS transistor is the basis for CMOS (Complementary MOS) circuits, which employs transistors of positive (P-Channel) and negative (N-Channel) charge carriers to achieve very low power consumption without degrading the required figures-of-merit of the circuit. Additionally, CMOS circuits can be fabricated at very low cost, which makes them attractive for a vast array of commercial applications.

Consequently, research on the high-frequency properties and behavior of MOS transistors is ongoing, and has become a very important of engineering curricula, both at the undergrad and graduate levels.

The purpose of this paper is to present an innovative approach to reading S-Parameters from Smith Charts that allows students to directly interpret the properties of the device under test (DUT). With this approach, they can easily judge several of the most important transistor parameters, such as matching conditions, open or short circuit non-idealities, input impedance and its capacitive component, the value of Source and Drain series resistances, leakage currents, channel resistance, substrate losses, and intrinsic capacitances, among others.