Amplification circuit usually consists of several amplification modules, each of which consists of one or more transistors. When the input signal passes through the first amplification module, the transistor will enhance the signal so that the amplitude of the output signal is greater than that of the input signal. Subsequently, the output signal will pass through the second amplification module to continue to enhance the amplitude of the signal. This process can be repeated several times until the required magnification is reached.
Amplifier circuits have many applications, including communication systems, medical equipment, audio equipment and measuring instruments. They can make weak signals more obvious, thus making information transmission more reliable.