Transistor Amplifier Circuits Unit 7 – RC Coupling
UNIT 7 – RC COUPLING
UNIT OBJECTIVE
At the completion of this unit, you will be able to demonstrate the operation of a two-stage RC-
coupled amplifier by using measured circuit conditions.
UNIT FUNDAMENTALS
Two amplifiers are cascaded when the output of the first amplifier is connected to the input of
the second amplifier. In a cascaded system, the first amplifier is called the first stage. The second
amplifier is called the second stage. Cascaded amplifiers achieve an overall gain higher than that
possible with one amplifier.
When a capacitor and one or more resistors connect the output of the first stage to the input of
the second stage, the amplifiers are RC (resistance-capacitance) coupled. With common-emitter
circuits, each amplifier inverts the input signal so that the output of the second stage is in phase
with the input of the first stage. The manner in which gain varies with the frequency of the input
signal is called frequency response.