What is single stage transistor amplifiers?

Introduction: 

What is single stage transistor amplifiers?

on of the most important characteristics of a signal is its amplitude. sometimes a signal may have the desired waveform and frequency, and yet  can not be used because of its small amplitude.This is  because the circuits or devices, that are to be operated with such signal as their input,need definite levels of amplitude of signal for proper operation. Thus the amplification or strengthening of the input signal become imperative. The device that amplifiers the input signal is called the amplifier.


Almost no electronic system can work without an amplifier. For instance radio receivers amplify very weak signal until they are strong enough to make the sound audioable . The transducers employed in medical and scientific investigations generate signals in microvolt or milivolt range which are incapable to operate indicating instruments. so, these signals need amplification thousand and million times so as to be strong enough to operate indicating instruments.


We have studied that a properly biased transistor increases the amplitude of a weak signal and so acts as an amplifiers. so an amplifiers may be defined as a device that increases the current voltage or power of an input signal with the help of a transistor by  furnishing the additional power from a separate source of supply.
                                When only one transistor with associated circuit is used for increasing the strength of a weak signal, the circuit is known as single stage amplifier.  it may be emphasised here that a practical amplifier using a number of stage of amplification.

we know that a transistor alone can not perform the function of amplification and some passive components, such as resistors and capacitors, and a biasing supply is to be connected.when an ac signal is applied between the base and emitter terminals of a properly biased transistor. a small base current starts flowing.