common collector circuit

In the above table, the collector load resistor Rc in the common emitter and common base amplifier circuit is the main component that determines the amplifier gain . (In addition to the resistor R, the load resistance also includes the inductance L of the LC resonant tank and the transformer primary coil inductance L in the transformer coupled amplifier).     In addition to the collector load, what determines the amplification gain is the internal resistance Rs of the signal source (in a multi-stage amplifier, it is the output resistance of the preamplifier , or the value after impedance transformation) and the external load resistance RL at the output end (in a multi-stage amplifier) In the first stage amplifier, it is the input resistance of the subsequent stage amplifier). Rs and RL have a non-negligible impact on the gain of the amplifier and must be considered in design and application.