High-frequency small-signal analysis of a common source amplifier — clearly explained This video walks through the high-frequency small-signal analysis of a common-source MOSFET amplifier, starting from the full small-signal model with parasitic capacitances included. Each parasitic element is identified and its impact on high-frequency behavior is interpreted. Using KCL and nodal analysis, the circuit is analyzed step by step to derive the frequency-dependent voltage gain. The algebra is then s