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7 years ago in Research Writing By Tarushi Yadav

Formula for bandwidth of cascaded amplifier

My conducting my research in electronics. My research topic is ‘Simulation of Ultra-Wideband Low Noise Amplifier using Cascaded amplifiers’. Can someone help me derive a formula for bandwidth shrinkage of cascaded amplifier?

All Answers (3 Answers In All)

By Rahul S Khemnar Answered 7 years ago

Are you considering single stage amplifier or multistage amplifiers?

By Tarushi Yadav Answered 7 years ago

Well, am using multistage amplifier.

By Rahul S Khemnar Answered 7 years ago

OK. Consider the DC gain of each amplifier is unity. The amplifier transfer function is then given by
H(s) = 1/s+1
Therefore the transfer function of n such amplifiers are
A(s) = (1/s+1)n
Solving for -3db roll frequency,
|A(jw)| = |(1/jw+1)|n = 1/2
So that (1/(wt)2 +1)2 = 1/2
The denominator of LHS gives you the value of 2
Which in return gives you the final equation,
w=1/21/n-1

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