Field-Effect Transistor (FET) Common Source (CS) Amplifier is one of the most widely used amplifier configurations in electronics, particularly in high-frequency applications. This amplifier utilizes a FET (such as JFET or MOSFET) in a common source arrangement, where the source terminal is common to both the input and output signals, and the signal is amplified between the gate and the drain.The common source amplifier operates by applying the input signal to the gate of the FET, which controls the flow of current from the source to the drain. The gate-source voltage (Vgs) modulates the channel resistance, allowing a varying current to pass from the source to the drain. This varying current is then converted into a voltage output by the load resistor placed at the drain terminal.When the input signal is applied at the gate, the resulting change in gate-source voltage (Vgs) causes a change in the drain current (Id). This current variation creates a voltage drop across the drain resistor (Rd), and the amplified output voltage is taken from the drain.