Improvement of the Effective Bandwidth of Multistage Amplifier by Cascading the Individual Two Stage Feedback Amplifiers

For the enhancement of amplitude of the signals, amplifiers are the circuits commonly used, where transistors either BJT or FET or op-amps are commonly used as the active elements of the same. Even though single stage amplifier provides certain amount of gain, it may not be enough for some applications. In this scenario, employment of multi-stage amplifiers is one of the effective solutions. Multistage cascaded amplifiers are very much important in the electronic industry because of the higher gain provided by them. One of challenges associated with the existing multistage cascaded amplifier is that they will reduce the effective bandwidth in a drastic manner which should be avoided. Related research works show good improvement in gain, but they are facing the drawback of higher reduction in the bandwidth. In this research study, the individual 2-stage cascaded amplifiers with series shunt feedback in first stage are cascaded to generate the higher stage multistage cascaded amplifier (MCA) with enhanced bandwidth than the conventional MCA. The proposed design is an optimized solution that improves the bandwidth of the n-stage MCA nearly by a factor less than n with reduction of gain by some amount.