Home | | Electronic Circuits I | Frequency Response of Multistage Amplifiers

Chapter: Electronic Circuits - Frequency Analysis of BJT and MOSFET Amplifiers

Frequency Response of Multistage Amplifiers

The bandwidth of multistage amplifier is always less than that of the bandwidth of single stage amplifier.

Frequency Response of Multistage Amplifiers:

 

The bandwidth of multistage amplifier is always less than that of the bandwidth of single stage amplifier.

 

1. Overall Lower Cut-off Frequency of Multistage Amplifier:


 


2. Overall Higher Cut-off Frequency of Multistage Amplifier:

 

Let us consider the upper 3dB frequency of n identical cascaded stages as fH(n). It is the frequency for which the overall gain falls to 1/√2 (3dB) of its midband value.


Taking nth root on both the sides,

21/n = 1 + [ fH(n)/fH ]2

21/n -1 = [ fH(n)/fH ]2

Taking square root on both the sides,

 

√21/n -1 = fH(n)/fH

fH(n) = fH √21/n -1

 

In multistage amplifier fL(n) is always greater than fL and fH(n) is always less than fH. So the bandwidth of multistage amplifier is always less than single stage amplifier.




Study Material, Lecturing Notes, Assignment, Reference, Wiki description explanation, brief detail
Electronic Circuits - Frequency Analysis of BJT and MOSFET Amplifiers : Frequency Response of Multistage Amplifiers |


Privacy Policy, Terms and Conditions, DMCA Policy and Compliant

Copyright © 2018-2023 BrainKart.com; All Rights Reserved. Developed by Therithal info, Chennai.