Two identical amplifiers each having an upper cut-off frequency f_H are cascaded with negligible loading effect. What is the modified f_H now?

Concept: Assuming all stages are identical and non-interacting (Proper impedance matching)\(f_{cascaded} = {f_H}{\sqrt{{2^\frac{1}{n}}-1}}\)​

where \(f_{cascaded} =\)Higher 3 -dB frequency of the multi-stage amplifier

 \(f_H\) = Higher 3 -dB frequency of all individual stages

 n= Number of stages in the multistage amplifier

 Putting n =2 we get,

 \(f_{cascaded}={f_H}{\sqrt{\sqrt{2}-1}}\)