Question

Cascading increases lower cut-off frequencies.

(a) True

(b) False

I had been asked this question during an interview.

My doubt stems from Cascaded Amplifier topic in portion General and Feedback Amplifiers of Analog Circuits

Answer 1

The correct choice is (a) True

For explanation I would say: Considering each amplifier has lower cut-off frequency fL1 then net lower cut-off frequency for a network of N cascaded amplifiers is fL = \(\frac{f_{L1}}{\sqrt{2^{1/N}}-1}\)

For N>=2, \(\sqrt{2^{1/N}}-1\) < 1, thus fL > fL1.